MAP INTELLIGENCE

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP80-01333A000300050001-1
• Release Decision: RIFPUB
• Original Classification: K
• Document Page Count: 432
• Document Creation Date: November 16, 2016
• Document Release Date: January 20, 1999
• Sequence Number: 1
• Publication Date: August 1, 1953
• Content Type: REPORT

Approved For ReleasAMOCKIMMMPtIAIRDTP80601333A00030005000-1-1
MAP INTELLIGENCE
FIRST EDITION
AUGUST 1953
ARMY MAP SERVICE
CORPS OF ENGINEERS
DEPARTMENT OF THE ARMY
WASHINGTON 16, D. C.
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71151.145
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AMS TRAINING AID NO. 6
MAP INTELLIGENCE
FIRST EDITION
AUGUST 1953
ARMY MAP SERVICE
CORPS OF ENGINEERS
DEPARTMENT OF THE ARM
WASHINGTON 25, D .0
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MAP INTELLIGENCE
Preface
College students who keep abreast of modern trends and techniques
are aware of the increasing number of maps being used for a variety
of purposes. Transportation agencies offer attractive maps of the
areas they service. Periodicals depict many phases of current events
upon simple maps and diagrams. Military and civic planners spend
hours in preparing and utilizing maps. Donald Duck waddles to South
America on a cartographic back-ground. In fact, no branch of modern
society is untouched by maps.
To utilize this tremendous increase in visual representation of
routes, statistics and tactical material, proper training in map
reading and construction is imperative to modern society. Thousands
of people are already employed by commercial and governmental agencies
to carry on the various phases of map preparation. These agencies
are increasing the scope of their operations daily but find that the
number of persons with adequate background and training to prepare
or use their product is limited. More systematic training of the
general and selected public will increase the quality and quantity
of map makers and map users.
MAP INTELLIGENCE is an outgrowth of experience acquired by the
Army Map Service in sponsoring an applied cartography program since 1951
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in selected colleges and universities. There has always been a
full realization that the text, APPLIED CARTOGRAPHY, contained
more material than could be adequately covered in one course.
The author, therefore, has attempted in the new text to separate
the many phases of map reading and interpretation from the
actual processes of map construction which will be presented in
a separate treatment and can be used as a separate course.
The primary objectives of NAP INTELLIGENCE is to give the
student (1) a general understanding of the many phases involved
in analyzing and interpreting different kinds of maps and (2) to
provide opportunities for applying what is presented in the
text.
The Commanding Officer of the Army Map Service will appreciate
reosiving comments and corrections directed toward improving sub?
sequent editions. Instructors and students should regard the
making of these suggestions as a cooperative endeavor to improve
the quality of future training and map utilization.
11
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TABLE OF CONTENTS
* ?4 1 0
Sting t,he,ScOefor Map IntellUence.
.Prqloguet . .
,De4initiqn of Terms
1 . . . .2
I
.Cartography. . t . . . t . ? . . .2
. ,Cartographic Representatioto 1 . . . .3
.Map Intelligence . ! 't t . . ? . .6
Vsqs or Cartographic ReprOex,.tations 1 ? . . . . .7
. 7
,General C:oncept . ; ; ? ; ? ? ? 4 ? 7
8
Site
Situation . 9
?General Education ... : . ...... 10
Classroom Illustration . . ..... . . . 10
,Tex7ua1 Clarification: . t : . ; : .. . .? 12
?ReSearch in Diverse kelds1 , . . . . . . 13
,Civil Planning and Rese4rc1 . . . 15
.Ownership RespqnsibilitY' , 1 . . . . . ,15
,Community Endeavors . . . . . . . . . . 16
Regional Integration.
. 17
, . . . .. :
,National.Unficationi ! : . . . . 19
International Cooperation 4, . ? . 20
Tilitary:Stratgy . . , 22
'Conversiqn froth Peace to 1A16.r . . . 22
'Many Maps for One War ' . 22
, .
Chapter II
',Loation,of Places . . t t
0 , 4
First',ImpreisiOns. ?. ; . . 25
Ge6graphIc coordinates : . . ,:
: . . . 26
Global Bases for CeograPhic COordinates : . . 26
Frame:of.Referdnce . : : 4 . .. . . 26
Ponta of Origin : : : '4 . ?: . . . . ? 33
;The Equator : .,: . ; ; ..... . . . 33
'The Prime Meridian . . . ....? .? 33
)Methods Of ilepiesentfnCGedgriphic Coordinates . .? . . 35
' 1The Sexagesi:mal SY'stem : : . . . . . . . . . 35
?Th C6nt6sitial'Systeth . : . '4 ..... . . 36
-Latitudeand LOnetude 5ym1o1s . ..... . ; 36
Cartographic Frameworks. : : : . . . '. . . . 37
'Clthracteristici of' Piojections '.. . 37
'Historical Ll'ackgrOund ' 37
Global Crit6ria for Evaluating Projections . . . 39
Attributes of an deal Projection . 40
Compromises of 'Existing 'PrOjections ? 41
iii
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. 4
Non-developable Surfaces . 48
Methods for Evolving Projections. ? ? . ?
Developable Surfaces E
Types of Projections 49
' Simple Conic '. '. , . . .' ? . ? . 50
?LaMbert 'Conformal COnic .. . ?. ? ? ? .?-? 53
-Alberls 'Conical Equal-Area. ? . * ? ? ? ? ? ? 55
..
Bonne. 0 . ? ? ? e o . ? ? 56
' POlyConic ? ? ? ? .. . . 58
'Modified Pdlyconic ? ? . . . 61
'
Sinusoidal , ' . I ? ? , ? .6 '? 62
'116-holographic . . ? ? ? $ ? ? ? 6 0 ,I. ? ? 64
Hdmolosine . . 65
Van ter Grinten . . . . ? ? ? 6 ? ? ? 67
Interrupted Projections. ? ? ,4 ? ? ? ? 4, ? 68
'Mercator, ', '. . .. ? . ? 70
-Transverse Mercator , . . . , . . . . 0 . . , . 73
Modification Of the Transverse Mercator for Military
purpOses :. . ? , . . -* . ? ? ? A 4 ? 75
,
-Azimuthal Proj'ections . 77
'Polar'GnOmonid0 ', ' . 80
"POlar Ster&ographic ? ... ? . ? ..... 4 ? ? 82
HRelationahiP of the 'Selection of a Projection to the Purpose
Area 'and Scale of the Map'. 84
Military Grids.> . .. , 0 . , ... . . ?. 85
From katicule to'Grid . . ? ? ? . . .. ? 85
. Reasons for Two Frameworks 86
:Locating'PlaceS . 87
'Giiring Directions. 0 . ? ? ? . .. ? .? ?? ? . . 89
Translating Distances . 92
Military Grid and Grid Reference :Systems ? ? .6 ? ? ? . 92
Universal Transverse Mercator Grid . .. ? ? ? ? . 92
, Universal Polar Stereographic Grid . 96
Military Grid Reference System 0 ? . ? . ? . 96
, ?
,PolyconiC Grid System . . .? ? . . . i , ? 99
,British Grid Systems. ? 0. f. .... . . .102
.Other Systems 0 6 4 4 0 . ? 6 * ? ? ? 4 .105
Measuring Devices: Scale . . . ? - ? ? . .105
Meaning of Scale . . ? . . . . . .? ? ? ? ? .105
.Classification of Maps According to Scale. ? ? , ? .109
Large Scale, . . . . . .110
.Medium Scale 111
Small Scale, . ? .111
Systems of Measurement 112
Crude Approximations 112
. Metric System 0 0 . 6 0 . ? . 113
Metric Convorsione a
, . 4 ? ? ? 4 4 .... s ,113
Adaptations of the English System 114
Notation of Scales 0 . . 115
Representative Fraction. . 115
Verbal Scale - One Inch to One Mile. . . . .- , . 416
Graphic Scale . , ? ? ? 0 ....... .116
?
How to use Graphic Scales .. . . . . . . . . .116
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Determination of Scale Values. . . . 118
No Scale Given 119
Representative 'Fraction Given; ." .. : . 119
-Graphic Scale Givdn : : : . : ... 119
Reduction; aid Enlargemeht 6f Scales' 120
laffect, of Reduction and Enlargement
120
ForMulae for Reduction and Enlargement
121
?Scaletxercise. ? ? ?
121
Control ? - ? ?
123
Cartographic Dependence on 'Other Fields
123
The' Meaning of Control ?
124
The Genesis -of Control
125
Datum Points and Datum Plane
128
. Datum Point ?
128
Mean Sea level or Datum Plane
128
Horizontal Control ?
130
Measuring Horizontal Distances with Tapes
131
Triangulation Field Work
132
Orders of Triangulation?
133
Public Land Survey System
134
Vertical Control
139
Relationship of Vertical to Horizontal Control
.
.
139
Markers for Control Points
144
Horizontal Control . .
?
144
Vertical Control e
.
.
144
Symbolization of Earth Patterns
.
145
Topographic Patterns
145
Contour Analyses from Training. Models
150
Control , , , . .
. ? ?
.
150
Contour Interval . e ?
S ?
151
Continuity of Contours . ?e . ?
.
152
Summits and Depressions
153
Slope Interpretation of Contours. ? . 154
Contour Response to Ridges and Valleys. . ? . .156
Man-made Alterations Expressed in Contours
158
Logical Contouring
159
Visualization of Topographic Features by Profiling. .
161
Construction of a Profile ? , , . ..
162
Form Lines - . , , ,
165
Color Interpretation of Topography .
165
Bands of Elevation
165
Shade of Color. .
166
'Hachure Method of Topographic Presentation ? ? .
167
Hydrography.. . ? ? .
169
Land Drainage ? ? . ? ? 0 a ? ? ? .
170
Streams
170
Lakes
172
Swamps. . . . .
? ? ? ? " 0 .
Oases,Springs and Other Special Hydrographic
Coastal Foreshore Features
Offshore Features.
Cultural Symbols . .
Population Symbols ? a
... 173
Features 174
175
? ? ?
176
178
? .178
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Transportation Symbols
Communications
_Boundaries
Vegetation ,
180
182
183
184
Strategit Importance.
184
Economic' IMPortance. . ? ? ? ? ?
?
?
.
.
,185
Marginal Data. . . . , ? ? ? ? ? ?
0
?
?
_.186
Map Identification. . ? . ? 0 ? ? * ?
?
?
0
g
.187
Sheet Identifications . . . ? ? . ?
?
?
.
.
.187
Index andIxdational Diagrams
.
.
.
.189
Separate Indexes. and Catalogues. . ....
.
.190
Significance of Dates . .......
.
.
.
.191
Sources and Type b of information Utilized
194
Coverage and Reliability Diagrams . . . .
.
.
Credit Notes . .. . . . . 0 . .. ' ....
.
.194
Data for Utilization of the Map
195
Reference Data . . . . ? , . . . .. '
.....
195
Declination Data
195
?
Chapter III
Planimetric Maps
201
Cadastral Information ... . .. : ...
.
.
.201
City Plans. . . , . . . . ? .. ,
.
...
.203
Highway Maps . . . . ' ?
204
Through-Way-Plans . ? . .... - ..
.
.
.
.
.204
Hypsometric Maps. . . . , . . , . . . '-
.
.
.
.
.205
Topographic Maps. . : . . . ' . . . . .
..
.
.205
Advantages and Limitations ? . ? ? ? ?
?
- ?
?
?
.205
General Adaptability of Topographic Map 6
207
Topographic Map _Interpretation Exercise '
210
Zonal Depiction of .Hypsometry ., . . 0 .
...
.223
Zones of Elevation in -Place of Contours .
.
?
?
?
.223
Illustrations of Zonation
224
Perspective Maps'
224
Specialized Types of Maps. . ? . . ......
226
Statistical Depictions
227
Essentials of Graphing. . . . . . . .
..
.
..
227
Types of Graphs
229
Statistical Maps. . . . .. ? ?
?
.
?
.
.233
.
Dot Maps . , . . 0- 6 ? .? 6 ? ......
233
Isoline Maps . . ?? ?? . ? 4 .. ...
.
.
.235
Isotherms . 4 ? .
235
Isohyets . . ? ? . . . . .
.
....
236
Isobars. '' . . ?? ? . . , , . ;
.....
236
Daily Weather Map . .. ., . .- ? .?
..
.-
.-
.
.237
Isogones . . ., . . ? . . '
.
, .
. .
?
.238
Isopleths . . . ? i I ?
238
Choropleths ,
238
Modelled Isoline Maps
239
_Graphs Superimposed on Maps .
239
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Special Patterns. , .
.
?
. .?
? ?
'
.
.240
PhysiGeology. ? , . . ? ? O O
ography.... . , . OO
, OOO
..
?
..
O ?
' ...
?
.
.
...222489194
. .242
Soils. . . ,, . . ....
. ?
. '
..
.
. -
.
.
.286
Minerals , . . . . . . . ? . , .....
Flora .and Fauna
? .....
287
288
, Medical Research
.
.
,Land Utilization . ,
289
Interpretative Cartography
290
Navigation and,Aeronautical Charts.
.
.
.
. .'
.
.293
Water Navigation charts
293
River.Charta . .. .
.
.
Pilot Charts ., .. .? ...
.
.
.
.
.295
Aeronautical Charts. ? . ? ? *
, . ,
?
?
?
c ?
?,?
.
.296
Sectional Aeronautical Chart.
.
.,
?
?
? .
.
?
.
.297
WOrld.Aeronautj.cal Chart
297
Aeronautical Planning Chart .
.
,
?
Relief Models.. ?. ? . I * ...
...
? ?
?
:
: :r'
Construction of Models . 299
Babson Model .. .. .. , 300
Utilization of Models ...... . 301
Model Exercise 302
, Chapter IV
, , t
Quality and Quantity of Coverage
Adequacy of Coverage .
National Standards of Map AcCuracy.* . . . . ?
Dependence,of.Adequacyupn National Economy . .
.
.
305
305
.305
.306
Dependence.of.Adequacy,upon Cartographic Acburacy.
*
.307
Areal Coverage of the prld by Topographic Maps . .
.
.309
Present Status ,
309
Exploratory Exercises .. . . .
.311
..Indexes of, Map Coverage
311
College Depository Program
314
Mapping Agencies and their Influence
315
United States
316
The United States Geological Survey . .
.
.316
The United States Coast and Geodetic Survey. ? .
?
.311
Agencies under the .Department of Defense
Other Federal Government Agencies
321
Canada.. . . ,.. ? ? ? ? ? ... ... .
.
.326
Department of Mines and Iechnical'Suryeys of Canada
.
.328
Army Survey Establishment of the Department of
_National DeXense . . . . . . ......
329
Provincial Agencies
.
The Americas.. , . . '. ' . ? . ' .......
.3Ag
Europe , . ,. .. .. .., .. . ,. ' .. ' ...... .
...
332
British
333
French
335
German
336
Italian
337
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Spanish
Portuguese . , , . .
Swiss. ,,, .. ? ? ? ? . .' .:
Belgium
Dutch. , ''. ? , . ip
Danish . . :
Norwegian ? . ? ? . ?
Swedish
Finnish ? ? . ? ? 0?
Estonian, Latvian and Lithuanian
..........
338
........
339
..
.......
339
339
,
??
, ?
0
?
?
?
340
?e.os
.??
340
340
?
341
.
. .
.....
342
Czechoslavakian . . . . . . . ...... .342
Polish . ..... . . . . .... . . .343
Hungarian: : : : .. . ? ? ? ? . ? ? 343
Austrian .. ? ... ? ? ? ? . . 343
,3
Rumanian ? a ?9? ?????0 ??? ?
? : 3
Bulgarian . . . . . . . ? ?? ? ? ??
44
Yugoslavian ? . ? ? ... ? ? ? 344
?
?
.......
....
.......
.
..
.
?
G
?
'
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: .
?
?
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,
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..
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?
0
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?
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.
? .345
. ,345
. ?345
. . 346
? ? 347
347
. ? 3444
. . 348
. ? 349
. . 350
351
, . 351
355
00
0.1?41
.
357
357
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.
. .
358
359
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..
?
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. .
360
360
361
?
?
?
?
?
? .
361
363
.
. ,
...
. .
363
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.....
.
364
.
......
364
,
.....
367
373
373
. "
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.
. .
374
374
Albanian . . ..
Greek ?. . , , . ? , .
Overall ,CoVerage . . . . ,
Africa . ? . - . . . ' ..... .
Union of South Africa .....
? Northern Africa . '. . . .
Spanish Influence ' .. ' . ? .....
French Influence . . . .
Italian Influence ..... .
British Influence . . . ....
Asia
Southwest Asia . . .... ..
India, Burma, Pakistan, and Thailand
Indonesia . . ?? 9 0 ? ? 0
China .
Japan . . . .......
U.S.S.R., . 9 ?
Australia and New Zealand . . . . .
Australia
New.Zealand ? ? . ? .
Summary . . . . . ? ? ? ?
Chapter V
Thelible of Photography in Map Intelligence
Photographs and Maps . . , . .
Types of Photography , ...
Terrestrial -Photography . . .
Aerial Photography . ; .' ..
Factors Affecting Aerial Photographs
Physical Conditions
Political Conditions . d
Altitude in Relation to Scale
. . ,
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Ground Relief Distortions 377
Effects of Airplane Deviations . ? ? ? , . ? ? 380
Interpretation of Aerial Photographs 383
Effects of Clock and Calendar . .
Utilizing Shadows on the Photo
Value of Relative Tones
Surroundings ? . ? ? a 0 OOOOOOOOO
385
387
388
Applications of Photographs to Map Reading
389
Textual Contributions to Map Intelligence .....
.
.
.
392
Field Survey Notes . . . . . .......
.
.
392
Travelers' and Explorers' Notes
394
Periodicals and Newspapers . . .......
.
.
.
395
Pamphlets and Guides
.
397
The Importance of Names
398
Problems of Toponymy
398
Conflicting Origins
398
Problems Arising From Linguistic Variations
.
.
q
.
400
Translation vs Transliteration . . . . .
.
.
.
401
Importance of Linguistic Sophistication
.
.
.
402
Appendix ? . ......... . . ?
It
?
?
0
403
Bibliography 1 P ? ? 0 ? ? ? * ? ?
406
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LIST OF ILLUSTRATIONS*
Figure 29 DETERMINATION OF LATITUDE LINE
Figure 30 ZENITH AND DECLINATION
Figure 32 DETERMINING DIRECTIONS
Figure 43 SKETCH OF EQUAL AREA, NON-CONFORMAL PROJECTION
Figure 45A MERCATOR LATITUDE-LONGITUDE RELATIONSHIPS
Figure 45B CONSTANCY OF DIRECTION
Figure 48 DEVELOPABLE SURFACES
Figure 51 BASIS OF CONIC PROJECTION
Figure 52 SIMPLE CONIC PROJECTION
Figure 53 CONE-GLOBE RELATIONSHIPS
Figure 57 BONNE PROJECTION
Figure 59 POLYCONIC PROJECTION
Figure 62 FIT OF MODIFIED POLYCONIC sHEETS OF INTERNATIONAL
MAP OF THE WORLD
Figure 65 WORLD HOMOLOGRAPHIC PROJECTION
Figure 66 WORLD SINUSOIDAL PROJECTION
Figure 67 VAN DER GRINTEN PROJECTION
Figure 69 ILLUSTRATION OF THE DEVELOPMENT OF PROJECTION
NETWORK FOR A GLOBE
Figure 70 WORLD INTERRUPTED HOMOLOSINE PROJECTION
Figure 72 MERCATOR PROJECTION
*To facilitate compilation of the text and provide an easy
method for finding illustrations, each Figure has been numbered
to correspond to the page on which it appears.. Illustrations
have been kept as near explanatory textual material as possible.
If more than one illustration was used on a given page, each
was assigned a letter in the order in which they were discussed.
Illustrations, therefore, are not numbered consecutively and are
less in total number than the final Figure numbers might suggest
without the above explanation.
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Figure 74 RELATIONSHIP OF BASIC CYLINDERS TO GLOBE
Figure 75 TRANSVERSE MERCATOR
Figure 76 MILITARY TRANSVERSE MERCATOR
Figure 78 PLACEMENT OF LIGHT TO OBTAIN GNOMONIC, EQUIDISTANT,
ORTHOGRAPHIC, AND STEREOGRAPHIC SPACING
Figure 82 POLAR GNOMONIC PROJECTION
Figure 83 POLAR STEREOGRAPHIC PROJECTION
Figure 90 GRAPHIC DETERMINATION OF AZIMUTH
Figure 94 GRAPHIC REASONING OF NEED FOR CALE FACTORS
Figure 95 GRID ZONE DESIGNATIONS OF THE MILITARY GRID REFERENCE
SYSTEM
Figure 101 U. S. POLYCONIC GRID REFERENCE SYSTEM
Figure 102 WORLD POLYCONIC GRID REFERENCE SYSTEM
Figure 103 ARRANGEMENT OF LETTERING IN 500,000 METER BLOCKS OR
100,000 METER SQUARES
Figure 107 VISUAL PRESENTATION OF SCALE
Figure 117 MEASURING A CURVED LINE
Figure 131 TRIANGULATION NETWORK
Figure 135 GENERAL LAND?OFFICE MAP
Figure 142 DETERMINATION OF ELEVATIONS
Figure 149 MODELING TECHNIQUES
Figure 155A ILLUSTRATION OF UNIFORM SLOPE
Figure 155B ILLUSTRATION OF CONVEX SLOPE
Figure 156 ILLUSTRATION OF CONCAVE SLOPE
Figure 157 CONTOUR RESPONSE TO RIDGES AND VALLEYS
Figure 164 ILLUSTRATION OF PROFILING
Figure 196 MAGNETIC DECLINATION GRAPH
Figure 310 STATUS OF TOPOGRAPHIC MAPPING
Figure 312 STATUS OF GEODETIC CONTROL SURVEYS
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.Figure 324 INDEX MAP OF CANADA
Figure
Figure
325 STATUS OF GEODETIC TRIANGULATION IN THE AMERICAS
A. Central America
B. South America
327 STATUS OF TOPOGRAPHIC MAPPING IN CANADA
A. One Inch to One Mile
B. One Inch to Four Miles
Figure 371 FLIGHT LINES
Figure 377 RELATIONSHIP OF PHOTO DETAIL TO ALTITUDE
Figure 378 IDEAL RELATIONSHIP OF PLANE TO GROUND
Figure 379 DIAGRAM SHOWING PARALLACTIC DISPLACEMENT DUE TO
TOPOGRAPHIC RELIEF
Figure 381 DISPLACEMENT DUE TO TIP OR TILT
Figure 382 ALIGNMENT OF PHOTOS
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CHAPTER 1
Introduction to Cartographic Representations
Setti4a the .'cene Eu, 1:1t-i4ifigen6d
Prolo,09
"All the worldts a stage" - This and many similar analogies
have been written about the earth as a stage upon which the kalei-
doscopic roles of human life are enacted. Each person spends his
life in close association with the earth scenes and, if he is wise
and able in harmonious adjustment to them.' All known civiliza-
tions are and have been inextricably tied to some earthly base,
It is true that members of these civilizations may temporarily
take to the air. EVentually, however, contact must be made with
the earthts surface. Scientific development, thus far, has not
reached the place where any form of civilization can be suspended
permanently in the atmosphere. Man and his machines must still
? rely upon earthly maps and instruments, food, fuel and repairs.
Even as on the theatrical stage, many different kinds of sets
and props are used and abused upon the earth stage. Pilots and
navigators are acutely aware of the importance laf the props they
use in staging 'scenes on the seas ahd in the air. They stake their
lives upon the adequacy of their instruments, maps and charts.
They clamor for improvements in these props and quickly adopt them
?
when they are devised. The average man, by comparison, is often
just a "ham" in the use of cartographic aids. He neglects or is
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only vaguely aware of the place and function of maps in the unfold-
-ing play of life. As a consequence he spends, fruitless hours and
untold monetary sums searching for, waiting for, and missing cues.
The purpose of this text is to present the salient facts
about, and Some suggestions for, the fuller use of cartographic
representations in the "play" of modern life. "Representations"
is used deliberately here because emphasis will be placed 'tfirough -
out this text upon the fact that there is no single map, chart, -Or
plan which is completely adequate for all phases of recreational,
educational, commercial, and professional utilization. In terms
of our play analogy, an assumption of an "all-purpose map" is
like assuming there is a single prop to be used in any stage sit-
uation. Obviously, this assumption is ridiculous even though many
current 'television programs seem to endorse it by the omnipresent
gun:
Definition of Terms
Many discussions tecome confused and bog down because some
simple or technical term or phrase is not clear to all concerned.
Conscientious effort will be exerted, therefore, to explain new
terms as they are introduced. Because of a wide difference in
background ofistudents, however, some terms may creep in, Unex-
plained, that are new to you. Question these foreigners immedi-
ately and naturalize them into your working vocabulary of carto-
graphic terms. Here are a few to begin on:
Cartography
Cartography is considered to be the science of preparing all
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types of maps, charts, and plans, and to include every operation
from original ground surveys to final printing of hap copies..
It includes production in the following three classes:
Class I deals with the techniques employed in making maps,
charts, and plans entirely, or principally, from original sur-
veys and observations. Such data may be obtained from engine-
ering surveys on the ground, aerial or ground photographs,
electronic or other photogrammetric methods.
Class II uses a product of Class I, for example, a topo-
graphic map, as the base upon which to make and record additional
original observations. Soil classification maps, geologic maps,
aeronautical charts, etc., are typical examples. This class
would also include maps that are offic-compiled from maps at
scales different from the one being prepared and other intelli-
gence.
Class III consists of office-compiled maps on which are re-
corded statistical data of many kinds. These maps are made en-
tirely from existing and available data. Maps showing location,
extent and character of many physical, economic, and social facts
and factors are in this category.1
Cartographic Representations
From the above explanation, it is apparent that cartography
lAdapted from Base Maps for World Needs prepared by the Com-
mittee of Experts on Cartography for the United Nations. New
York:Lake Success, Sales No. 1949 1.19, 1949, p.51 This pam-
phlet providet a good general summary of the topic and should be
scanned by everyone interested in maps.
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means the actual preparation of all forms of maps, charts and
plans. The term cartographic representations, therefore, will be
used in this text to include all the products of cartography in..-
stead of spelling them out each time. It has been adopted by the
author for the following additional reason. There are no current clear-
cut dsfinitiohs'of or distinctions among maps, charts and plans.
111.a.- At One time the distinction between maps and charts
was based upon the idea that maps portrayed land features prim-
arily. If water bodies intervened, as in the case of continen-
tal or world depictions, they were included only to maintain the
desired relationships among land masses.
Charts.- Were used primarily to show details of large water
bodies. Only a limited extent of the coastal areas needed as a
flsetting" for the water features were included. Bathymetric de-
tails (depths), currents, and other aids or hazards to navigation
usually were shown on these charts.
When man took to the air, he needed some special form of car-
tographic representation to aid him. Since this need was related
to a branch of navigation, it was probably logical to classify the
maps made for this use as charts. Actually, the aviator soars
over both land and sea.. In his flights the ocean depths are of
no great consequence to him since he flies well above them. His
only concern is in safely traversing the water in the shortest
distance and time commensurate with the capacity of his plane and
the number of stops necessary for refueling and conducting mili-
tary or civilian operations. As he approaches land or flies above
it, however, he is concerned with terrain features, especially
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relief, ground indentifications, and landing fields. Special
aeronautical information is superimposed upon topographic maps
for these purposes. 'Thus the aeronautical chart is often a
topographic map with navigational aids and data added to it.
Flans.- The third category, "plan", is usually ap?died to
maps that show a large amount of detail of a small area. For
example, a city plan generally shows the transportational pattern
of streets, railroads, and water bodies where they exist. It
also may show prominent buildings and other spots of civic pride
or interest. Some plans are made especially to show property
lines for ownership and taxation purposes. Once again, however,
some foreign countries, notably Great Britain, use the term plan
to include maps of greater areal extent than ono village, town
or city.
Each of the above types of cartographic representations will
be elaborated in greater detail later. These first generaliza-
tions are offered to illustrate the intermingling and overlapping
of terms and types. In the final analysis, each type is meant to
accomplish a common objective and that is to show a part or all
of the surface of the earth and any of its features selected for
a specific purpose. The selection may entail: the relief of a
given land area or, that below a water surface; the natural fea-
tures such as drainage and vegetation; and tho man-made cultural
features or, it may entail a combination of two or all such de-
tails. If those selections are correlated with some organized
network which establishes a locational pattern for the earth, the
end product is a map. Since "map" is a simple word, it is and.
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often will be used instead of the longer "cartographic representa-
tions" in this and other texts.
Intelligence
Several names were considered for this introductory course in
map reading and interpretation. Nap Intelligence was finally se-
lected because of its connotation and denotation. On the one hand,
it implies that someone, namely you, is to make intelligent use of
maps to gain a vast amount of knowledge concerning the earth, its
patterns and their interrelationships. This can only be accomp-
lished by using Intelligence in analyzing and interpreting the
material shown on and among maps.
On the other hand, you will be helPed toward the acquisi-
tion of a professional definition of Map Intelligence which anti-
cipates as well as interprets maps. By this definition Map In-
telligence is taken to mean the Product resulting from the pro-
cessing of all geographic, cartographic and related information
that provide data necessary for the preparation or interpretation
of maps charts, and plans. In this definition, I-elated infor-
mation refers to all documents, facts or observations that may
throw light on the varied aspects of map interpretation and/or
preparation. The methods by which information is manufaCtUred
into intelligence are: collection, selection, evaluation, an-
alysis, interpretation, and integration. In practice, some of
these are combined into a single operation, but basically the
distinction among them still exists.
A short discussion, at this point, of the many ways that maps
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are or can be useful in modern life should help you to understand
'why some map intelligence is needed by every conscientous citizen
of the world.
Uses for Cartographic nesentations
Location of Elallt
General Conata
The most universal and apparently time-honored use of maps
is for locational purposes. It is trite, but none the less perti-
nent to remind you of th, fact that wars and continuing emergen.-
cies have created unprecedented map consciousness among a tre-
mendous public. Nearly every family or person has had some friend
or relative visiting or invading an unfamiliar place. The stay-
at-homes, consequently, demand a map upon which to locate the
foreign spot. Too often, these folks are frustrated in their
efforts because map reading is as foreign to them as the spot
they seek. To lessen the consternation which ensues, newspapers
and even comic books have included simple diagrams as substi-
tutes for maps. News commentators, broadcasting through the
medium of television, have slot up blackboards in the studio.
Sketches made on these boards during the broadcast indicate the
approximate location and relationship of places in the news.
(Even this crude technique overcomes some of the laymen's fear of
maps and may lead ultimately to more accurate maps and capable
map users.)
There are two reasons for locating a place: To find its
site or precise geographic location and to determine its situa-
? tion.or location in relation to surrounding features. The
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average map patron is usually more concerned with the latter rea-
son even though he may not think of his intention as "situation".
Every proficient map user, nontheless, should be familiar with
the two terms and their implications.
Site
Any material object from the smallest blade of grass to the
tallest skyscraper or highest mountain occupies a definite site
on the face of the earth. Even supposedly mobile objects occupy
-
a specific site at any given instant of time. This instantaneous
fixation is the basis for motion pictures in which a series of
"stills" are turned rapidly to create the illusion of motion. In
the case of either the film or the earth site, its exact position
can be determined and recorded. In mapping only the positioning
of fixed objects is practical.
The degree of precision with which sites can be located de-
pends upon the adequacy of the map itself and the ability of the
user to read it. Methods by which an exact location can be shown
cartographically will be discussed later. At this point, let it
suffice to say that some maps are so hastily or so designedly
drawn that it is extremely difficult or impossible to pin-point
exact locations. One commonplace example will illustrate this
statement:
Literally millions of "road maps" are distributed each year
by American petroleum companies. These road diagrams satisfy
or confuse automobile enthusiasts and cartographic laymen. The
term diagram is used here instead of map since in most cases
these eXamples are not true maps. So long as route numbers, city,
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town and village names and distance approximations between them
are shown, the average user is satisfied. Road-map makers have
learned that precise methods for locating places will not be used,
and so have devised index ambers and letters for zonal, not pre-
cise, location of a place. Anyone who has tried to transfer in-
formation from such a soor0e. to a more precisely drawn map base
can vouch for the grossneas of zonal locations.
Situation
In defense of road maps; it should be said that their pri-
mary function is not to pin-point sites but rather to aid motor-
ists in selecting routes and estimating distances along them.
Road maps clearly identify major roads by route numbers assigned
to them. They show distances between individual populated places
by means of small numbers and between selected towns by means of
symbols such as red stars, and similar colored numbers represent-
ing the mileage between these smbols. Thus, the map-user
really places more stress on situation than site since he is lo-
cating one place in relation to another.
Determination of situation is probably the most common ob-
jective of the general map public. They are not so much in-
terested in pin-pointing places as they are in finding out
roughly whore a place, say Hiroshima is in relation to a con-
tinent, (Asia), the rest of Japan, or to Tokyo. They are seek-
ing a general orientation of one place in respect to something
they know or have vaguely heard about.
T.11,6tter-injOrMed map reader has a similar objective
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in ascertaining the situation of an earth feature. The major dif-
ference between him and the novice is that he examines the 'feature
in relation to appropriate details surrounding it, such as trans-
portation, vegetation, drainage, or other natural and cultural
features. Such utilization requires more accuracy than any road
map pretends to achieve.
General Education
Classroom Illustration
You may assume that classroom wall maps are adequate media
for location analyses and other forms of map reading. Unfortuna-
tely, this assumption has widespread acceptance because most stu-
dents are accustomed to staring at wall maps throughout their edu-
cational career and have had little Opportunity to evaluate(their
limitations by comparison with other types of maps.
Any canny cartographer or intelligent map user understands
the purpose of wall maps and the reasons for their limitations.
In the first place, most such maps are designed Tor clarity and
good distance visibility. Since the map is to be used in fairly
large rooms, colors, symbols and identifications are selected to
be seen from most pats of the room by individuals with normal
eyesight. Furthermore, publishers must anticipate a large volume
of sales to justify the expense of producing such a map. Because
highly localized maps have a limited sale at present, these pub-
lishers offer maps that are generalized enough to be sold in
widely separated areas such as throughout the Continental United
States. Consequently, the average wall map is designed to bring
out broad generalizations and overall relationships among country,
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continental, and world features rather than to show detailed in-
formation about any one place.
Each student should learn to appreciate the fact that most
wall map depictions are restricted by the size of the media on
which they are presented in comparison to the infinitely greater
size of the land mass they represent. On them a large pottion ,
of the earth's surface is squeezed into a few inches. This com-
pression precludes any detailed visualization. Only a few of
the most salient features can be shown and even these are gen-
eralized and stylized. Further elaboration of this limitation
will be presented later in the discussion of scales and symbols.
Another limitation of many continental wall map series is
related to the importance of continents in comparison with their
size. For example, Europe is a small sub-continent of Asia. So
many important countries and cities have grown on this continent,
however, that they crowd each other on a map. Most wall map
series, consequently, show Europe on a comparatively much larger
scale than the other continents in order to maintain visibility
of details. As a result, students often acquire the impression
that Europe is much bigger than it actually is. Correction of
this erroneous impression should be achieved by consistant re-
ferral to a good globe which is the only true proportional
representation of the entire surface of the earth.
Presentation and acceptance of these and several other
limitations should strengthen your realization that classroom
wall maps are valuable teaching devises for showing locations of
selected details. Only preliminary generalizations concerning
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patterns of earth distributions and their relationships should
be expected from the average commercially produced wall map.
Textual Clarification
Increasing map-consciousness and the resultant demand for
cartographic representations have influenced many modern publica-
tions. The tendency during the last twenty or so years has been
to include more and more visual aids in text books. The expense
involved in meeting such demands is one strong factor in the in-
creased cost of textbooks. Do you get your money's worth by
using these aids in clarifying the textual material presented?
A wealth of simple but clear maps in texts enables the
reader to pick up details about general or specialized regional
discussions.: The awakening concept of including inset maps to
orient small local areas to larger and more familiar masses is a
aecided asset and should not be ignored or neglected.
Textual maps should,be used not only to clarify the material
presented therein but also to provide understanding of features
that 'cannot be shown on or gleaned from wall maps. The ability
to achieve this correlation is one index of intelligent map '
ability.
Quite obviously no specialized purposes can be assigned to a
discussion of textual maps since they can run the whole gamut of
map utilizatiori. Their only limitations depend upon the foret.'_
sight of the author, the amount of money that can be expended on
the project and the ultimate ability of the reader to digest
their meaning.
If no maps are included to cover a special phase of textual
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development, grab an Atlas). Atlases cover a wide variety of gen-
eral and interpretative cartographic representations. Once you
have mastered the organization and learned the extent of mapped
information in the Atlas at your disposal, use it as easily as
you do a table fork. Make it the tool for conveying food for
.thought about earth features from book to mind.
Research in Diverse Fields
Althou6n maps are a valuable tool of the geologist and
geographer, they are not the exclusive possession of these
groups. Good cartographic representations save thousands of
words and help to crystalize facts and figures in diverse fields
of interest. No branch of knowledge is exempted. In medicine,
the distribution or localization of diseases, physical weaknesses,
availability of medical care, sources of drugs and standards of
medical proficiency are only a few of the factors reducable to
maps. Maps shOwing the geneis.and ev6luticn of- wor'ds,.alPha-
bets and inflections would be helpful to anyone interested in
languages. Physicists and psychologists, sociologists and
seismologists, economists and etymologists, theolcgists and
thespians all have theories, principles and findings that can
and should be shown cartographically. It seems to the author
that the burden of students might be lightened if some advocates
of special disciplines were forced to reduce their circumspect
discussions to simple map terms.
Anyone; doing.research in specialized fields involving
detailed analysis and interpretation of small areas must go be-
yond the preliminary generalizations made on small scale maps.
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Such research demands accurate and detailed representations of
the area in question. The researcher, therefore, learns to
evaluate and use many different types of maps at varying scales.
Many of these maps will be the product of other research for en-
tirely different purposes.
'Versatile utilization can be made of maps that reveal dis-
tribution patterns. Such patterns graphically illustrate the
truism of world interrelationships. Th,)y emphasize the simi-
larity of cultural and natural complexes in far-flung,parts of
the world. These conditions can be broken down into various con-
tributing components by careful study of the distribution patterns
of heterogeneous data,. For example, large sections of land in
Utah Ar?entia and India rec.uire some form of irrigation if pro-
ductive agriculture is to be carried on. Specific engineering
problems and agricultrual techniques in each area are dependent
upon local conditions and economic stage of development. Even
among these there may be common denominators which facilitate in-
terchange of teohni4ues4,
Although fuller understanding of an area is achieved by
superimposition of maps of many types of distributions, some in-
sight accrues from examining just the transportation and communi-
cation patterns. The unification and economic advancement of an
area is reflected in the complexity of its transportation net-
work and the possibilities for raoid exchange of ideas through
communication channels. Something can even be inferred about
the social stage from patterns of the sales of comic books and
golf clubst
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Students correlating distribution patterns shown on maps
must be cautioned constantly to cheek their map findings care-
fully with other sources. litman beings inject unsuspected in-
gredients into the most logical products of sensible correla-
tion. Political religious and proVincial biases often curtail
or obstruct the optimuM utilUation of a given area or idea.
Normally such adaptations are explained in reading materials,
not on maps.
Civil mads1441E and Research
Ownership Responsibility
Several phases of cartography are of special value to civil
activities. One of the prOoaLltiona to We taken by a sensible
prospective property owner is to verify the boundaries of the
land ie intends to buy. He may run in trouble in clearing his
title in many areas even within the United States. Involved
A
inheritance, claims by adverse possession (squatters' rights) or
confused disposition of large estates has created conflicting
and overlapping claims. (The saying, "It takes a Philadelphia
lawyer to understand it." arose from the fact that during the early
settlement of eastern Pennsylvania, so many domestic and foreign
dispositions were made of the same land, that many Philadelphia
lawyers spent a large shars of their time, and gained their repu-
tations, in settling land disputes.)
In areas where such problems have been untangled or consti-
tute a minor proportion of the total property settlement, care-
ful records of property disposition are usually kept. Often
maps depicting all the property lines and survey markers in a
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given place are available at the Recorders' offices.
Property owners generally seek,the%protection of fire and
Other forms of insurance. Since such insurance rates are based
upon location, construction and evaluation of property, accurate
records of these factors are compiled and kept up-to-date. One
of the' best sources for this type of information for populated
places in the United States are the Sandborn Insurance Atlases.
There are approximately 2000 volumes covering both incorporated
and unincorporated places where growth has been sufficient to
warrant formal compilation of actuarial statistics. Each volume
cover
a specific area and includes a wealth of detailed informa-
tion about each individual piece of property, including water
supply, public'utilities and similar related data. Anyone doing
an urban study will find these atlases invaluable.
Community Endeavors
Modern development of new areas and redevelopment of old ones
take planning. Maladjtistments are inevitable unless there is
constant checking. Often the rapid growth of an area gives rise
:to inadequacies not envisioned by earlier groups. Mbst.modern
cities that have evolved from older nucleii are classic illustra-
tions. Original city fathers could not foresee the congestion,
lateral growth, and internal deterioration resulting from scienti-
fic innovations concocted by their grandchildren.
Modern society has given birth to marvels.. On the other
hand, it has nurtured urban monstrosities. Extensive and costly
transformation must be planned to make cities socially and eco-
nomically more acceptable. Transportation arteries which were
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adequate for the traffic flow of yester-year are now suffering
from arteriosclerosis. If the blood of modern transportation is
to flow, constrictions must be eased and new arteries created by
engineering surgery. Older editions of maps are used as X-rays
to identify the danger spots. New maps must be prepared to in-
sure overall diagnostic improvement. Four lane arteries that do
not serve the heart are poor solutions which can be avoided by
proper analysis of the total transportation system.
Industrial and residential locations are planned by taking
into consideration transportation, sanitation, taxation, recrea-
tion, and many other l'ations". Each of these factors is develop-
able upon maps which afford clearer visualization of their re-
lationships than many thousands of words of text.
amLaal Integration
Greater than the problems of urban planning but intimately
associated with them are those arising from regional integration.
Urban conglomerations are often nucleii for regional activities.
The size of the urban nucleus is no index of its importance to
regional.integration. A very small town may be the focus for
political, legislative, financial, commercial and transporta-
tional facilities and thereby exert a tremendous influence on
the surrounding region. The approximate extent of such a service
area constitutes one form of regional analysis which can be de-
duced from special maps or reduced to them.
Regional integration may, and usually does, go far beyond
the confines of the service area of a particular community.
Divergent interests may stymy rapid integration. Nevertheless,
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if enough time is permitted to elapse, many of these groups will
encounter problems they cannot solve alone, and will thereby be-
come _reconciled to cooperation. Both private and public interests
undertake projects which will lead ultimately toward these ends.
.A few examples will serve to illustrate the immediate needs and
long-range planning toward regional goals that can be aided by
adequate mapping and maps.
Development of iron ore deposits in new -areas requires sur-
.veying of the extent of-the promoters' holdings. Maps of geo-
logical structure and terrain must either be made or procured :
from existing sources, before actual operations can begin. Re-
gional planning must also be done to- insure workers comfort and
the steady flow of the necessary supplies and products. Sources
of water, construction materials, and food must be sought and in-
-mired. If the project develops into a successful, large-scale
operation, it will influence the whole region around it. Research
and cartographic representations will be needed in guiding this
development. The steel companies, or company involved, will
reach out for the assistance of other groups and government.
There are many examples of regional planning of developed
and poorly developed areas in the United States. One of these
is the Missouri Valley Authority. The Missouri Valley Authority
regional integration is envisioned through master plans encom-
passing about 1/5 of the land area of the United States. Thou-
sands of maps have been compiled and are being used in various
phases of this project. Some degree of success is being
achieved through acceptance of a few of the findings and re-
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coMmendations of the Aut4or4.-ty even though it has not cleared
ill of the political hurdles set before it. Maps are strong
selling aids in showing small groups how local projects con-
tribute to their personal ed economic betterment.
National Unification
S;ze, shapo, location, abundance or-lack ofnaturarresourees,
and the social, political and. economic stages of development are
tactors that influence national unification. Maps of these per-
tinent factors are indispensable to students of individual and
collective national scenes. In studying the problems of Brazil
in striving for national unification, for example, the great size
of the nation, which is larger than the United States, must be
evaluated in terms of the poor to nonexistent transportation fa-
cilities over most of the interior areas, Natural resources and
factors such as climate must be examined to anticipate whether
they will aid or hinder national unification. Native and/or im-
ported population must be considered as potential workers.
Whether they will work together, fight among themselves or not
work at all can be anticipated in part from their cultural and
natural backgrounds. All these and many more tangibles and in-
tangibles will help a student to understand what Brazil or any
other country must face in working toward real national unity.
Many variables constantly present themselves which either
complicate or simplify the situation. Sectional jealousies and
economic fear become strongly entrenched in isolated, under-
developed or poorly endowed areas. Many of these sectional
biases grow purely on the basis of ignorance of the value of
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national unity. Development of education, transportation and com-
munication tend to break them down. Examination of maps showing
these factors may give a clue to the local condition in relation
to its degree of national cooperation.
It is very helpful to have maps or a mapping system estab-
lished in advance of internal national growth. Unfortunately,
these aids were not ready in many of the nations of the world.
Consequently, staggering sums of money and time have been wasted
in conducting individual and overlapping projects. As the rail-
roads pushed across North America, for example, they ran limited
surveys and made choices of rights-of-way that were poor and
would have been unnecessary if adequate topographic mapping had
been available. Just the cost of fuel required to pull steep
grades and to carry heavy trains along needlessly winding routes
would have paid for many series of topographic maps covering the
entire continent.
At a later date, maps were sought for diagnostic improve-
ment of areas struggling toward better development. Industries
often consider and eliminate these areas since no adequate maps
are available to show the suitability of sites for constructing
factories or warehouses and their relation to markets and ma-
terials. All of these are tied up with national unification
since they strengthen the exchange of goods and the optimum uti-
lization of manpower and other resources.
International Cooperation
Indications and actual evidence of the feasibility of in-
ternational cooperation have been accumulating rapidly in the
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last three or four decades in spite of, or because of, world un-
rest 'and conflict. Some of those cooperative endeavors begin at
the very root of international understanding which is the indivi-
dualls right to live decently. The Food and Agriculture Organi-
Zation, because of its obligation to work for the improvement of
agriculture, forestry and fisheries, endeavors to promote the
rational use of land and the renewable natural resources. Nothing
is more basic to life than this. While FAO is working toward
such a goal, CARE is attempting to make life more bearable in
the interim.
Gigantic strides, unheralded to the common man, are being
taken by many other working groups within the United Nations
master organization. Educational programs are in progress which
include representatives from many nations. A group of geograp-
hers has been studying the teaching techniques and tools basic
to the dissemination of sound geographic information. One of
the important geographic tools is maps. They serve the edu-
cators, agriculturalists, and all branches of United Nations.
In recognition of their importance, a small cartographic sec-
tion of United Nations is working on the availability and dis-
tribution of maps all over the world.
One type of map has been decidedly influenced by inter-
national agreement. The International Civil Aviation Organi-
zation (ICAO) was responsible for.establishing the Standards
and Recommended Practices for Charts for special and general
purposes for air navigation. It has. standardizedthe symbols
and allocated areas of responsibility for the production of the
4
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1:1,000,000 World Aeronautical Chart. Such an undertaking illus-
trates the general trend toward standardization of commercial,
professional and even military procedures through international
concert.
Military Strategy
Conversion from Peace to War
The interdependence among peoples and nations becomes pain-
fully obvious when national and international maladjustments lead
to war. When times of crises arrive, many nations are caught
with their planning down. Valuable hours are lost in scurrying
around to find out who can contribute what and how much to cor-
rect peace-time short-sightedness. Prior planning lessens the
danger of such confusion and may even prove indispensable to sur-
vival. Knowledge of the distribution and requirements of vital
industries is requisite to prompt conversion from peace to war.
If strategists can call for and get a great variety of maps, their
task is simplified. Maps of flyways and byways; barrens and
forests; steel mills and grist mills, and thousands of other cul-
tural and natural distributions contribute to and indicate re-
arrangement of the master strategy.
Many. Maps for One War
Conflicts of global proportions are the price paid during
the evolution of a unified "One World." As more and more of the
parts are drawn into the whole, greater conflicts seem inevit-
able. Tactical operations in modern warfare take into account
not only far-flung theaters, but also great numbers of men and
materials. These necessitate all types of maps in astronomical
22
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quantities. During World War II the newly created Army Map
Service, alone, produced 40,000 different maps and distributed a
total of 500,000,000 sheets. Execution of the North African
t44paign within this war required 10,000,000 copies of 1,000
she'ts. For the Normandy invasion 3,000 sheets were prepared
and 70,000,000 copies disseminated.1
A single movement may require several different types of
maps for its execution. If it is to be a combined land sea and
air operation, air and water navigation charts must be procured
and studied for approaches and landing maneuvers. Beach heads
and landing strips are studied on existing maps or plotted on
new ones. Large scale maps for the foot soldier must be coordi-
nated with tactical maps and charts for jet pilots. This in it-
self is no small feat when you consider the difference in dis-
tance traversed in a given time by the marching columns and the
phenomenal jet plane. The pilot of the latter would hardly be
able to locate the area covered by the former's map before he
would bie many miles away.
Raised relief models help field and headquarters officers
visualize the types of topography with which they must cope.
Routes for long-range movements, places for concealment can be
tentatively selected and later checked with larger scale maps.
Planimetric and topographic maps, charts and plans each
play a part in the detailed planning of overall and localized
...emsamm./../.1?????????.????????????ImIII..11/11.00.11.
litArms and the Map - Millitary Mapping by A.M.S.0 Print Vol-IV
No. 2, 1946
?IIIMIIIIIII/m11/11???????????MIMENIFINMIIII?IMONII.????????1.1101.10
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strategy. These may be confiscated from the enemy, borrowed from
allies or supplied by topographic units in the field and military
and/or civilian mapping agencies back home. The net results of
acquisitions from all sources equal huge volumes of maps. These
volumes mean little, however, unless the individual maps are re-
liable and the personnel who accumulate them know how to use them
competently.
Lengthy definitions and discussions will never make you a
map expert. Acquisition of this skill can come with the analysis
and use of individual maps. Analysis should come logically be-
fore any intensive use, so that you understand the prop you are
using. The best way to learn about a thing is to actually or
mentally take it apart or put it together. Since we are dealing
with the. products of cartography, we must take them apart to de-
termine what ingredients were combined to make them.
24
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.CHAPTEA 2
Map Ingredients
First Impressions
As the curtain rises on the first act of a play, the audi-
ence is pleased or dissatisfied by its initial glimpse of the
scenery. If the individual parts of this scenery have been well
_selected and arranged, the spectators will not immediately be
aware of the parts unlesa their attention is directed to them by
a specific action. Others may consciously or subconsciously be-
gin to analyze what makes the scene appropriate to the mood and
circumstances.
Maps have the same general reception. Many will look at
them, note that they are oprettyfi or "ugly? and overlook the
contributing details. Oter more sensitive individuals will
analyze what makes the map both attractive and useful.
From the largest wall map to the smallest desk edition, an
earnest effort is usually exerted to make each one as attractive
as possible since too often uaye appeal!' is the only factor con-
sidered in the adoption or rejection of a map. Even better-
informed prospective map-users will be influenced by this con-
sideration in selecting from among several accurate maps. Any
map that is pleasing to the eye encourages further inspection of
it. Such appeal is achieved by application of color wherever and
whenever it is feasible; by clear symbolization of the features
shown; by careful placement of identifications, and by pleasing.
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combinations of lettering.
All of the above should be combined with other aspects be-
fore a map becomes a really valuable tool. Utility is achieved
by careful selection of information; by adequate aids to utili-
zation of the information, and by some accurately determined
method for locating area and details within this area both in re-
lation to the map itself and to the portion of the earth repre-
sented.
Test your first impressions of several maps available to you.
Consider why you react as you do to them, Then let us begin ana-
lyzing the many ingredients needed to make a map appealing and,
above all, useful.
Geographic Coordinates
Global Bases for Geographic Coordinates
Frame of Reference
Any map is a representation of a part or all of the earth.
It is tied inextricably to the earth and to be useful it should
show how the tie is accomplished from earth to map details. This
necessitates a frame of reference, which is a very popular term
in academic literature. Connotations of this term frequently be-
come exceedingly involved. When applied to global and map repre-
sentations, obtuseness is unnecessary. The Cartographic "frame
of reference" means a systematic network of lines upon which
?
land and water positions of the world can be located. This net-
work is referred to as a system of geographic coordinates.
To determine the origin and practicality of geographic co-
ordinates we must first review a few simple facts about the earth.
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The earth can be represented as a sphere.for most practical pur-
poses. (From the standpoint of physics, it is inevitable that a
rapidly rotating mass, such as the earth, should assume an essen-
tially spherieal shape over a long period of time. Furthermore,
since the earth is rotating upon an axis, centrifugal force
causes it to bulge away from the center and flatten near the
poles, thus creating an oblate spheroid. This bulging makes the
equatorial.about 27 miles longer than the polar diameter. Con-
verted to circumference difference it 10 24,902 miles compared
tO 24,860 or 42 miles. Slight variations, which have been com-
puted for these differences will be discussed later. The dif-
ferential is so slight that the earth will be called a sphere
for purposes of this review.)
The next plain fact is that the earth is too big to deal
with as a unit. It must be divided in some manner. Geographic
coordinates provide convenient reference points for the deter-
mination of location, distance and direction relationships on
the surface of the earth or its representations. Many compli-
cated trigonometric formulae are available for establishing a
network of these lines on a sphere. Frequently, mathematicians
and educators take delight in flaunting their knowledge before
non-mathematical-minded students. The result is a fear of and
confusion about the way the earth has been divided by means of
geographic coordinates for convenience of its inhabitants.
These coordinates are actually no more complicated to use than
a simple graph having a X and a Y axis. Instead of being called
X and Y, however, they are called latitude and longitude or,
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parallels and meridians.
Latitude - The X coordinates are latitudes or parallels.
When the earth is assumed to be a sphere with a north south
axis, a line can be drawn midway between the two poles and at
right angles or perpendicular to this axis. 'Mi.; midline is the
Equator, and latitude means the angular distance north or south
of this midline. Since the Equator is the line of origin from
which latitude is measured, it is labelled 0 latitude. Then
from the Equator to each pole is one forth of a circle (3600) or
900. Consequently, whenever the degree method of angular mea-
surement is used, latitudes can never be numbered more than 90.
(Another method for dividing a circle will be discussed later.)
Since you are working with a round earth even though lati-
tude measurement in terms of angles is logical determination of
the origin of these angles is difficult to visualize unless
you can use your imagination. To help you see how these angles
can be derived graphically, you must imagine thatthe earth has
been cut in half from pole to pole. In Figure 29 you now see the
earths' polar circumference as a circle and the equatorial
and polar axes or planes revealed in their true perpendicular
alignment, intersecting at the center of the earth. Another
line has been drawn to represent a plane of latitude. By
drawing a radius from the axial intersection to the point where
this plane cuts the circumference and extending it slightly, we
can measure the angle of any latitude in question. Perhaps you
remember that when two lines are drawn parallel to each other
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PLANE OF LaTITLIDE
QU a TOR 161 .
POL.
? ' 29
and a diagonal line is drawn between them, opposite angles are
equal. Thm the angle fomed between the radius diagonal and
the equatorial axis, A would be. the same as that formedty the
plane of the latitude with the radius AI.
The ahgle.in Figure 29 :I, approximately 30(1,, Therefore,
.the par-11 1 of latitude i 300 N of the equator. Any number
of other latitude lines could be determined in a similar fa?
shion. They mint not be even degree units, but might be
minutes,Seconds- or.fracticn of seconds or one degree apart.
Multiple, degreeanits are-often used on maps and globes simply
to lessen the theoretically possible maze of lines but any line
that is parallel to the evator is theoretically a latitude
line.
Another approach itay be code to the same problem by.. using.
factors which can be seen ,;in the surfaCe of the earth without
visualivinc two a' ha a. buried in the exact aenter of the
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earth. This method can be applied at two dates in the calendar
year and at the instant when the sun reaches its highest point
(or noon) in the sky on these dates. The dates are tonincident
With the vernal and autumnal equinoxes, or March 21 and roughly
September 22. If the sun cooperates, an observer at any given
spot on the surface of the earth can calculate the angle the sun
makes with a point directly overhead. Overhead is the Zenith and
the angle of the sun from it, is Declination. See Figure 30.
(This declination can be
proved to equal the latitude
of the observer.) All obser-
ZEIOTH L__
vers standing the same dis-
tance from the equator re-
cord the same angle. If a line
were drawn around the earth '
connecting their locations, it
would be a complete circle of
1//
y assmava
latitude. FIGURE 30
After you comprehend the derivation of latitudes, it is
necessary only to remember that latitudes are lines running
parallel to the equator and are used like city blocks to tell
haw far north or south of the equator a particular spot or
long street (parallel) is located.
Longitude - The next consideration is where along a partIcular
latitude,l-in the example, 30?N, a given spot, X, is located.
Locating X could turnout to be an earth-encircling journey if ,no
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limiting coordinates were supplied. Derivation of these coor-
dinaes is more difficult than derivation of lalitude is.
There is no true'E-W axis to correspond to the N-S polar axis.
Dividing the globe into two hemispheres and running meridians
parallel to the dividing line would Man a complete disregard of
a fundamental sun-earth relationship and pole to pole orientation.
You know that the Sun is one of the stars in the planetary
system of which Earth is a part. The earth moves about the sun
at the rate of one revolution every 3654 days. As a result of
this revolution earth inhabitants seem to see the sun move
through one complete path in the sky each year. Furthermore,
as the earth rotates on its axis, daily sun patterns are drawn*
If observers could be lined up along a straight line running from
N pole to S pole, they would all see the sun reach its highest
point in the sky for the same day simultaneously. Other obser-
vers oriented along a N-S line to the east of the first group-
would have already completed a like experiment and those to the
west would be awaiting their turn. An infinite number of lines
extending from pole to pole could be drawn in this fashion and
each would be a meridian.
Each meridian would be one-half of the equatorial circum-
ference or Great Circle in length. All would converge at the
two poles. It is common sense to realize they could not be
parallel to each other as the latitude lines are. Instead, they
are equally spaced along any parallel, but the distance between
meridians along succeeding parallels decreases poleward from the
equator.
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When the zero meridian is established, common-sense again
dictates that numbering around ,the circle must stop somewhere or
-else 0.would coincide with_360. upon completion of the numbering.
The meridian.whichtogether with 0 on the opposite side completes
a great circle, consequently, is numbered 180?. Moving eastward
from 0, under this sywteml'numbers increase to 1800 and then .I-
crease back to 0. All numbers eastward between 0 and 180 are la-
belled E. Those progressively eastward from 180 to 0 are labelled
74 It is now possible to locate an exact spot in terms of its
latitude north .or south ofthe equator .and its longitude east or
-west of the Prima Meridian and 1800..
Determining Directions. -.Notice the numerical values for
meridians increase in the direction, relative to the PrimeMeri-
dian, for which they are to be named. The same is true- for
It is useful to remember this axiom. You may be called
upon to work with a map of a small area which does not include the
equator, prime meridian or 180?. By noting the progression of
w.
00 80 70 60 50 40 10 jo 10
/ /0
10
40
F'IGuas 32
latitude and longitude numbers, you will be able to fit the par-
ticular sheet into its proper earth position. In terms of east-
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west, north-south coordinates, where are A and B on figure 32?
Do not confuse the locational east-westcvalues assigned by
the above technique with active movement in either direction.
1:04 ;an travel around the world always going either east or west
relative to a fixed starting point by following a compass in
either direction. In contrast, however, directions always
ckange when you move across the poles. For example, from Green-
land to Antarctica is south. If you proceed over the south
pole 4nd move toward Siberia, you will be going. north.
Points a Origin,
The Equator
The Equator so logically is a point of origin for the deter-
mination and numbering of latitudes, that no conflict has ever
arisen, so far as the author knows, over using it for this
purpose.
The Prime Meridian
Dissension and divergence have been common to the choosing
of a point of origin for meridian numbering. Almost every country
at one time used a zero meridian passing through some nationally
prominent place, such as a capital or, a place where an out-
standing observatory was located. Increasing contacts, occa-
sioned by travel and economic and political associations, created
navigational and cartographic confusion in trying to coordinate
such a variety of prime meridians. One of the earliest attempts
to settle on one prime meridian was made by an international
group meeting in Paris in 1634. They decided to select a neu-
tral meridian rather than one then in use by any country,
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They chose 19? 55' 03" W of Paris. Since this was an awkward'
string of numbers to handle, the geographer, Delisle, shortened it
to 20? W of Paris. By association it soon came to be thought of
as the Paris meridian in disguise which discredited its intended
neutrality and strengthened the arguments for an adoption of an-
other point of origin such as Greenwich.
Most of the major nations of the world finally came to a
common agreement at the International Conference which was held
at Washington, D.C. in 1884. By this time, Greenwich had slowly
gained popularity and was being used as the Prime Meridian on
more than 3/4 of the maps and charts published throughout the
world. Since this choice was based upon a first order observa-
tory that also had wide influence upon time synchronization, the
conference logically endorsed Greenwich as the Prime Meridian.
Even today, however, there are some 20 different prime meri-
,dians_in use. Although many of these are seldom seen, some of
them appear on important foreign map series and should be recog-
nized. Many older European map series are based upon Ferro,
which is the western-most of the Canary Islands. A meridian pass -
ing,through this region was long thought to be the western limit
of the world. As knowledge of the world increased, mapping kept
pace in many respects, but Ferro Meridian has been retained into
the present century.
The Pantheon in Paris which is 20 201 13.95" east of Greenwich
is another origin of longitude used on many map series compiled or
influenced by the French. Spanish maps were based on still an-
other, through Madrid; Norwegian, on Oslo; and Italian, on Monte
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Mario in Rome.1 Most new mapping compiled in these countries is
being converted to Greenwich, but some of the other origins per-
sist or appear on sheets that are still extant. These examples
are sufficient to warn users of foreign maps to beware. Check
the origin of longitude! Any calculations based on Greenwich
would be false and would cause incorrect interpretation or cor-
relations if some other meridian had been used as the prime
meridian.
Methods of Representing Geographic aagagsa
Sexagesimal 2.7.:Lam
Just as there are variations in the origin of longitude so .
are there variations in the methods for representing geographic
coordinates. One variation arises from different methods used
in the division of a circle, The degree system that was used
above in the determination of latitude and longitude distances is
the one with which you are familiar. .It is a part of the sexa-
gesimal system which is based upon divisions of sixty.
The whole sexagesimal numbering system evolved from ancient
observation of and reverence roc heavenly bodies. Since many
ancients were shepherds, they obviously had ample opportunity to
watch the sky. ' They noted that the moon waxed and waned every
30 days: One moon round was called a moonth. Twelve moonths
(months) elapsed from spring to spring. Since this completed
a cycle or circle, 30 x 12 made 360. All circles were divided
accordingly. Sixty was an even multiple or divider of 12 and
'See Appendix for complete list.
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360: so was used to represent the number of units in 1 degree, I
minute, etc. this sexagesimal system became the basis for the
English units of measurements for many things besides a circle--
of which, more later.
Centesimal System
Ciroles can be divided in,other liays 'in site Of the-saction
of:long-usage giVen to 360?degrceS 60 minutes and 60 seconds..
The centesimal system was originated in France in the 18th century.
It is based on a decimal subdivision of the circle. The complete
circle is divided into 400 parts called GRADES, or more commonly,
_Grads. Each grade is divided into 100 minute's and each minute
into 100seconds. Values may be written in grades, minutes and
seconds or merely in grades and a decimal fraction. For example,
4,grades, 97 minutes, 30 and 25 hundredths seconds = 4G 0-30.25
or 4.G973025. Note: minute and second symbols slope in the re-
verse of sexigesimal symbols.
If you wish to convert from the centesimal to the sexigesimal
or vice-versa, you work on the basis of a quadrant which equals
100G or 90?. One grade, therefore, equals .9 degrees.
4G 97\30.25 x .9 = 4?.4757225
.4757225 x 60 minutes = 40.2E0.53335
.53335 x 60 seconds = 4?28'32.601u
Thu,
If a greater degree of accuracy is required, .of or .000001G =
.003".
Latitudd and Longitude Symbols
LatituL.e and longitude are shown on maps in several ways.
Usually, when only the geographic coordinate method is used, the
latitude and longitude lines are drawn from neat line to neat
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line on the map sheet. (The neat line is the finishing line
around the body of a map and should not be confused with the
margin beyond). Each line is appropriately numbered in the mar-
gin. Ordinarily, the lines representing full degrees are comb-
pletely numbered and intermediate lines are numbered by minutes
or seconds, omitting the larger units. (Refer to: USGS Ten-
nessee: Chattanooga).
In cases where full lines running across the body of a map
might interfere with detail or are unnecessary to the reading
thereof, a system of ticks and crosses is employed. Ticks are
placed inside the neat line and true vertical-horizontal croSses
are distributed throughout the sheet where latitude and logitude
lines intersect. such crosses are often called INTERCEPTS. (An-
derson Island, Sheet 1478 11 NW)
Some foreign maps contain only marginal notations of latitude
and logitude. A long straight-edge must be used between these no-
tations if internal intersections are desired. (Wolfstein West,
Sheet 58 W)
Cartographic Frameworks
Characteristics of ProJections
Historical Background
The task of the cartographer would be far less complex if
the earth were flat, as the early Christian theologians insisted.
Convenient discs were mandated by them as the shape of the earth
in spite of many scientific hypotheses and proofs that the world
was round. These clerics may have believed that they could keep
track of their flock better on an earth that had definite linear
extent. ("World Without End" was written many centuries latter
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when sphericity of the earth was a generally accepted fact.)
Furthermore, religious adherents and potential converts could be
kept in order by gruesome tales of horrible monsters inhabiting
the border regions. Religious followers also feared entry into
Hads by falling off the edges of the flat earth. Few wanted to
attempt to disprove this depiction of terrestrial limits by shov-
ing off into monster-infested seas and supernaturally inhabited
lands. Such bravery was built up gradually through succeeding
generations. A few men of each generation pressed outward a .
little farther from the familiar and well defined Mediterranean
lands. When they lived to tell such tales as Marco Polo and
many forgotten adventurers recited, others took heart. Columbus
symbolizes many men who conquered fear to prove the earth is round.
While the adventurers were pushing the physical frontiers
further and further afield, mathematicians and scientists were
broadening the cartographic horizons. The historical develop-
ment of maps is a fascinating tale. Many excellent books are de-
voted entirely to the subject. The reader is referred to these
if he is interested in the background for present cartographic
achievements.1 Historical cartography had to be omitted from this
present text because of time and scope factors. It is felt that
you will have a full enough schedule in learning how to use and
interpret maps of the present century.
10ne of the most scholarly but at the same time enjoyable volumes
is Lloyd Brown, The Story of Maps New York: Little BrOwn, 1949.
Others are listed in the Bibliography at the end of this text.
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Global Criteria for Evaluating Projections
So many varieties of projections have been devised and have
received limited or widespread acceptance that the average person
is either lost or, by inertia, fails to recognize any difference
among ,projections. As soon as he learns there is no such thing
as an all-purpose map base and accepts the conclusion of a news-
paper writer who titled his article "All Maps are Liars"10 then
he must learn some method for evaluating the strengths and weak-
nesses of individual projections. The 5lobe itself provides the
necessary tools. Let's take the time to identify these tools so
we can use them. Take your turn at the classroom globe to verify
and digest the following points;
(1) The equator is a line drawn mid-way between
the two poles and perpendicular to the polar
axis.
(2) Each line of latitude is parallel to the
equator.
(3) The interval or spacing between each parallel
is equal to the same number of degrees.
(4) The equator is the only great circle line of
latitude.2 All others are small circles, the
1"All Maps are Liars" - New York Times, Sunday Map,azine, '
Oct. 11 1942.
2A treat circle is any circle whose plane passes through the
.center Of the globe and cuts the circumference at two points
180 degrees apart.
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total length or circumference of which de-
creases in relation to their distance away
from the equator.
(5) Each ilieridian is a great circle in length.
(Two opposite meridians make one great cir-
cle.)
(6) All meridians converge at the two polar points.
(7) Spacing between meridians is equal along any
parallel, but the total space between
meri-
dians decreases poleward.
(8) Latitude and Longitude lines cross at right
angles.
(9) All areas are in correct scale ratio to earth
measurements.
If you-will digest the meaning of these criteria, you will
have a usawli :or the dissection of any projection to decide its
general value for a particular job. You must, of course, know
whether shape size, or direction accuracy is most essentials
Attribute* of an Ideal Projection
An ideal projection would conform exactly to the global cri-
teria and any map developed on it would truly represent earth fea-
tures Su oh a nap would contain four important attributes required
of a perfect projection. These are:
(1) Mapped areas conform to their true earth shapes
(2) Areas retain their correct size in ratio of
earth to map scale.
0) Directions anywhere on the map are identical
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to true earth directions.
(4) Stated distances anywhere on the map are in
correct proportion to true earth distances.
In essence then, these four properties control conformality
,*f shape, equality of area and correctness of directions and
distances. If all were present, the much-sought perfect pro-
jection would have been achieved.
Compromises of Existing Projections
The very nature of the relationship of round earth to flat
paper makes a perfect projection impossible. Any large part of
a spherical surface cannot be laid out on a flat surface with-
out shrinking, breaking or stretching it somewhere. It follows,
therefore, that it is impossible to lay out a flat unbroken net-
work of lines that will conform to all the global criteria listed
above. Consequently, it is.equally impossible to achieve the
four properties required to make a perfect flat map. The problem
has stumped the experts, but has led to many compromise projec-
tions which contain one or more of the properties or close approxi-
mations to them. These are obtained in the following ways.
ConformaliLz - in cartography means that the shape of a map
surface at laz given spot is identical to the shape of the corres-
ponding spot on the earth. This definition sometimes causes con-
fusion when it is falsely enlarged to imply the shape of a large
area such as a continent. "At any given spot" is underscored to
emphasize the restriction of conformality to small areas or. spots
and not extension to overall shape.
On any given projection, the angle at which each parallel
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crosses each meridian governs-the shape of the area adjacent to
intersection. According to our global criteria each meridian
crosses each parallel at right angles. Preservation of right
angles-together with the same scale along the parallel and meri-
dian at any point makes a projection CONFORMAL.
An ordinary pack of index cards can be used to illustrate
conformality or the loss of it by alteration from right to acute
or obtuse angles. Take the whole pack of cards and stack it ver-
tically, taking care to Maintain right angles at the corners.
Draw a vertical line down the center of one side. Assume that
this line and the vertical edge lines are meridians and the planes
of given cards are parallels. Any earth feature correctly drawn
on this assumed network, or projection, will be conformal.
Now push the individual cards in such a way as to change the
edge angles but not the unity of the pack. One edge of the pack
will now approximate the shape of a meridian as it varys in re-
sponse-to changing the angle of each card (parallel) to the edge
line (meridian). The overall length of the once vertical edge
will be expanded while that of the central vertical remains
constant (Note: A new central vertical must be drawn for each
change in card arrangement.) Call the vertical the central
meridian and the outer edge the limiting or bounding meridian.
On the globe each meridian is equal in length; whereas, on the
card illustration, the edge line is longer than the central
vertical. Any map shape drawn under these conditions will not
conform to its original earth shape even though its area is pro-
served. Figure 43 shows this on an actual projection net on
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SKETCH OF EQUAL AREA, NONeCONFORULL PROJECT 1014
90
90 ao 70 60 SO 40 30 20 q0 10
A
FIGURE 43
which the meridian length between AeB is shorter than between C-B.
True Directions -.Quiz masters delight in stumping contes-
tants by asking, "Which is farther north, the northern boundary
of Maine or the northern boundary of Minnesota?". This question
has probably been asked enough time so that many know the correct
answer, Minnesota, without appreciating why it doesn't look it on
many maps.
This "false" look is due to the fact that parallels have
been stretched into circles which bend equatorward near the
center of tho projection and curve upward toward the edges. To
avoid this misinterpretation of directions, the student learns
that direction e true along projection lines. Relative
direction must be read in relation to these lines. In other
words, to ?see the reason fel- the correct answer to the quiz,
the Maine and Minnesota boundaries are determined in relation
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to a nearby parallel, let's say 500 N. Maine's northern boundary
is definitely south of this parallel (479) while one section of
Minnesota's lies north of it (519).
Iffilen conformality is present, directions will be correct
along parallels and meridians. Correctness in any direction
and conformality can be achieved by uniform distortion of net-
work intervals when the lines of this net are kept at right
angles. The famous Mercator Projection was developed for the
express purpose of retaining true direction, not only along
projection lines, but also diagonally between them.
On the Mercator, all parallels and meridians are straight
lines constructed at right angles to each other. Because meri-
dians should converge at the two poles, there is distortion of
the poleward intervals between them when they are kept parallel
as on the Mercator projection,. To compensate for this stretch-
ing, Mercator determined the amount of exaggeration of inter-
vals between longitudes along each parallel north (or south) of
the Equator. Then he increased the size of intervals between
each successive line of latitude, which should be equal, in
the same ratio as the longitude interval distortion at that
latitude. Study the diagrams opposite which present graphi-
cally what Merdator did mathematically,
44
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Lortic:%:,-Lomi;icroch,
vialfZP
Li
LAT! -root' ....4:51,16.1TUrre
C.'. tk1 C-t=
---
O.. C 1ccz ?
t.) 'FE Ci) L POC
LINES
OU 5T 4T P ? LI_j& 1W TOE
ISTO T ONI
PLJ T k.10143 C kIVERGEN C, Of
t?-1
RI rj 5.
FIGU
The purpcse cf trtcbfl'g par7ae1 intor-vals in the sane
ratio as meridian intervo'L; is to make direction q ooristant even
thr'ugh mnp ddstano,03 L. can ink.roas4A7Ly distnrted polar.
Ohservethat w. the .xoemr-ing cgrii anilrgiug the S12e of
the square does not change ri-le diroctior f the dia,Tonal.
FIGURE 4513
Projections (.4,n also bc contructed on a plane from one
arbitrary centr41 point to Lake cotion trm!. in thi6 type
projection, tha .f.:;drecticin at all -1),-Lnte on the ql.Ap, z:117, taken
rroL the central mint, -tu5.? same aa thay are on the earth,
Lt dcas not necesarily follow, humwer, that directions -taken
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Al]. projections which evolve from a central point on a plane
are called AZIMUTHAL. Azimuth means direction. Many of the nine
global critg4a and one or more of the desired map properties are
sacrificed to achieve correct azimuths or directions, but equal
area Cart /1/0 $11441100.
ay...4 int- Tne mai;-maker must choose between conforMality
and equal arat or equivalence. These two axe mutually eeclusive
on a map, although they are criteria derived from the globe net-
work, An BWAL Ana 4ap preserves the correct ratio of mapped
areas to those pn the teeth. To do this en a flat surface means
that shape muat be sacrificed or compromised. Our card experiment
substantiated this statement. During its progress, no card was
added or subtracted, so the total area remained constant ,as shapos
were changed.
Figure 43 illustrates equal area as well as non-conformality.
It can be proved that if the total length of each parallel 4nd that
of the central meridian are drawn in true proportion to earth scale
and if the parallel and meridian spacing is also true, then ttbe re-
sulting map is equal area.
Most equal area projectdons are the result of advanoed mathe-
matical formulae in which area has been the major consideration.
The Figure just referred to shows a projection on which the meri4
diens are sine curves and the length ot each parallel is found by
taking tha cosine of the angle of the latitude times the length of
the equator. After the length of each latitude is thus determined/
each is then truly spaced along a central meridian of proportionally
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correct length in relation to true earth distance.
True Distances - There is no specific formula for attaining
true distances. Proportional correctness of distances is deter-
mined in several ways and may vary within as well as among map
sheets. Normally, distances will be fairly accurate near the
central meridian if a projection is hung on one. When parallels
are drawn to scale and correctly spaced, distances will be true
along them. Calculation of diagonal distances may be very
erroneous on small-scale maps unless they are of the equal area
variety. More will be said about the determination of distances
in the discussion of scales, but a preliminary word of caution
is in order here. Be sure of the properties of the projection
you are using, and assume generally that distances you derive
from zaps covering large areas are only approximations. Check
these estimates against more accurate sources if distance values
are critical.
Methods for Evolving Projections
The term projection is actually a misnomer when applied to
all types of geographic networks. Most of them cannot be pro-
jected. Projection means literally reproducing an object by
its shadow, Many so-called projections are actually derived
mathematically and could never be developed from shadows. Long
usage, however, has SID firmly entrenched the term, projection,
in reference to any geographic framework, that no attempt will
be made in this text to refute it.
Generally, projections can be divided into two groups
derived from the difference between true projections and other
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means of development. These groupsare based upon.developable
and nony-developabie surfaces.
?uty212e1041 Surfaces
\ Atly enrface that can be flattened and is capable of receiv-
ing lines projected or drawn directly from an assumed globe, is
developablet this.category are cones, cylinders and planes.
A cone maybe wrapped around a globe and a source of light fixed
so that it will cause shadows of the geographic network to be cast
on thor,inside of the cone. The shadow et can be drawn and the
cone cut open and 14i flat to reveal the projection in a work-
ing position? Cylindrical projections can be developed in simi-
lar fashiOn. A third developable rface s a plane. It can be
oriented to',a globe at. any one selected spot as this diagram shows.
DVELOPABL6 SUaFAGS
LINE OF P I t-4 T Or
TAPJG?Ecticy T4WGENCY
FIGUAE 48 '
ELTZAtIillitSurfa's
Many projections have evolved as slight modifications of the
basic cone, cylinder or plane to globe relationship. Any line may
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be curved or straightened to achieve better proportions. Such
modifications that are simple enough to visualize the resulting
projections, are classed with the developable group. Actually,
though, they should be placed in the non-developable group. As
DAme implies, these projections can never be transferred by
401444 of a'source of light casting shadows on surfaces capable
of being flattened. All non-developable projections are derived
by mathematical computations and formulae. Fortunately, the re-
sults 'of, much of this advanced thinking have been reduced to
tabular form which requires a minimum of mathematical skill to
translate into map projections.
Types of Projections
We will not be greatly concerned with all the refinements
for computing and constructing projections. We will be concerned
though in developing your ability to recognize and evaluate se-
veral of the most popular types. Any part of the following dis-
cussion can be amplified by studying more technical treatises.
Such detailed treatment can be found in several books listed in
the Bibliography.
One of the factors to be kept in mind in choosing or ana-
lyzing a projection is the amount of earth area covered by the
map. Any type of projection is suitable for maps of small areal
extent. Fidelity is good near the point or line of tangency and
usually for short distances on either side of it in the case of
developable projections. (TANGENCY is defined as the place where
the basic globe touches the map surface, Figure 48) On non-
developable projections, fidelity is good near the point of origin
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or along lines that have been constructed true to earth specifica-
tions. It is only when we deal with large parts or all of the
earth that we must be critical of and careful in our choice of
projections.
There is no way by which projections can be divided into mu-
tually exclusive classes. Many texts attempt to group projections
as conic, equal area, and azimuthal. Closer examination will re-
veal that most projections may fall into two of these classes and
the attempt to make them fit one class leads to confusion. This
author has attempted, therefore, to present projections in a tran-
sitional order without drawing any classification boundaries be-
tween conical, cylindrical and plane derivations leading to con-
formality, equivalence, or azimuthality.
Simple Conic
Although the basic conic projection is rarely used for other
than small areas, it is worthy of comment since it is the basis
for many conical variations.
Projection is easy to visualize and easy to construct. An
assumed cone is wrapped around a globe (Fig. 48B) so that it is
tangent along a given parallel located between a pole and the
equator, but not at either one (A Gone made tangent to the equator
becomes a cylinder, Fig. 48A; and tangent to a pole, a plane, Fig.
48C). The remaining parallels are arcs of concentric circles
emanating from the apex of the cone whose height is established
by the selected standard parallel. The radius of each circle is
determined by the extension of truly spaced latitude intervals
on the globe to the cone. This extension alters the spacing as
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can-bovseen,en Fig. .5, longitude intervals are calculated
and stepped off along the standard parallel. Straight line meri-
dians are drawn through these points to the false pole estab-
lished by the apex of the cone.
EQUATOA
.3A313 OF CONIC PROJECTION
LINE. OF reMGI4ay
OR. 5T -$DOKI) LLEL
? ? ? ? 65.
Each latitude is
.APrx_,,?.4.1111111111111111111111 centric circle
an arc of a con-
P1111111
114411
?1? 04t
4101# \
,
\
\
True longitude
spacing along
30?N
Meridians are
straight lines
drawn from apex
through points
\ established on
30?
FIGURE 51
All.angles are.rightangles so a map developed on this fan-
like network would be nearly conformal and that is about all that
canbesaid for it.. One slight change, however, will improve it.
Latitudes can. be spaced truly rather than according to where their
shadows:fall on the cone. The pole is no 16nger a point, but be-
cemaS a small circular parallel When this change is made. The
resultant projection is a SIMPLE CONIC or just CONIC.
This projeCtion can be recognized by its equally spaced
-parallels which are arcs of concentric circles and by the straight
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51.
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line meridians equally spaced along any parallel and converging,
but not meeting at the pole. Fig. 52.
SIMPLE CONIC PRO.LCTIuN
EQUfITOR
FIGUR3 52
The Simple Conic Projection is most appropriate as a frame-
work for middle latitude areas near a deliberately selected point
of tangency which becomes the standard parallel. This projection
is not used for world maps because of the extreme accrual of dis-
tortion in the hemisphere opposite the one in which the standard
parallel is selected. The opposing pole would not be a point,
but a great ',hoop skirt". Even in the same hemisphere, features
are distorted poleward or equatorward as can be seen on Fig.52,
and by comparing the shape of North America on this figure with
that shown on any good globe.
'Distances are true along the standard parallel and are fairly
accurate along meridians. Shapes and area are also generally good
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in this limited area. Great circles can be represented by nearly
straight lines anywhere on the map and are straight lines along
meridians. Thua, the Simple Conic Projection is easy to construct
and is acceptable for mapOng middle latitude areas of limited la?
titudinal but unlimited longitudinal extent.
Lambert Conformal Conic
We have seen that mapping along a standard parallel of a
conic projection cones close to fulfilling the desirable proper?
ties of a flat map. Thie area of acceptability can be* increased
by aelectiag two atandard parallels instead of one. Care must be
exercised, however, in the selection. If parallels are too far
apart, compreaaion will make the internal distances too short and
the external distances too great in relation to true distances
along the standard parallels. You can see, in Fig. 53 that the
surface area between the two atandard parallels is cut Off by the
edge of the cone. Mils roughly illustrates why scale adjustments
must be Made to compensate for the loos. Fotice, too, the greater
divergence of the cone away from the globe when the two parallels
FIGiaz 53
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are widely spaced.
Generally, the two standard parallels are selected to be one-
sixth and five-sixths respectively of the total central longitude
distance to be represented. For examplel'there will be a maximum
scale error of 21 per cent for a map of the United States based
on 330 and 45?.N. By this choice, the maximlm error for the eco-
nomically most important area between 301? and 47i? is only i of
one percent; and the greater 21 per cent occurs in southern
Florida. If the standards are placed at 29? and 45?, a maximum
of 1 1/5 per cent is obtained, but at the expense of the central
portions.1
These percentages mean an error in mileage equal to the per-
centage value in'100 miles, i.e., one half of one per cent equals
mile in each 100 miles. The length is too short between the two
standard parallels and too long beyond them. In other words, on
a map of the United States based on 330 and 45?, the total distance
from coast to coast on longitude 390 is about 13 miles too short
and in the same distance along 25?, would be about 75 miles too
long. This is not 'bad when you consider there are approximately
3000 miles over which to distribute the 13 miles, and only portion
of the United States near 25? is the narrow tip of Florida which
would be less than 2 miles too wide on the projection, The re-
maining Parallels ai-e'arcs of concentric circles'spiced at in-r
creasingly-lai.ger intervais"north'and gouth of thestandard
'Statistics concerning various projections have been adopted
from:Deetz,C.H.and Adams, 0.S. Elements of MIE Projections. U.S.
Dept.of Commerce, Coast and Geodetic Survey, Special Publication
No. 68.
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parallels in a manner similar to those shown for the basic conic
in Fig. 51. Arcs of longitude are represented in their true
lengths along the two standard parallels. Straight lines are
drawn through these points to intersect at the point of origin
for parallel arcs. The scale adjustment and right angled inter-
section of parallels and meridians makes this a conformal pro-
jection. The projection can be recognized by the combination of
characteristicsIlisted above.
Conformal Conic Projections are well-adapted to mapping
problems involving wide longitudinal and limited latitudinal
extent. The change in scale which makes directions true and the
retention of correct shapes makes the projection suitable for
Aeronautical and Radio Direction Finding Charts for cross-
country flying.
Albers Conical Equal-Area
Further mathematical refinement of the relation of latitude-
longitude s-pacing was made by Albers to create and equal area pro-
jection. He calculated the radii for two standard parallels se-
lected at one sixth of the meridianal distance from both the
north and south limits of the map, so as to make the projection
equal area. Next he stepped off arcs of true longitude along
each standard parallel and drew straight line meridians through
them to the center of origin for the parallels. This center is
not the pole. A pole is represented by a circle as it is in the
Simple Conic. Because equal area is maintained, the remaining
paraIlels are spaced at decreasing intervals north and south of
the two standards.
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When a map of the United ,States is based on 29i and 45i?, the
distance error is kept'to'14.,per pent. It is about 1% too larie
in the central areas. This error is hardly greater, as Raisz points
out, than the expansion and contraction of paper with changes of
humidityl. Areas are made equal, and directions are very close
to true. Although the projection is not strictly conformal, shapes
are good within the reasonable limits of the two standard par-
allels. Consequently, in the author's opinion, it is the best
projection available for maps of any east-west and north-south
extent roughly equivalent to that of the United States and should
enjoy wider popularity than it does.
The recognizable traits of this projection are the straight
line meridians that converge toward, but do not meet, at a pole
which is represented by a circle instead of by a point and, by
circular parallels that are spaced at decreasing iftteiArals north
and south of the two standard parallels.
Bonne
Another mathematically-derived variation of conic projections
is the Bonne. This projection is developed upon a standard par-
allel selected preferably somewhere in the middle latitudes. A
cone is made tangent at this point and the distance between the
point of tangency and the apex is the radius for describing the
arc of the selected parallel. Fig. 57
A central meridian is constructed as a vertical in the
1Raisz, Erwin General Cartography New York: McGraw-Hill,
19481 p. 75
01.1111.Mmmos?Owomme.
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4. POINT Fo oe5cR :BING ARCS OF
PA RA LLELs.
NoRTH F'aILE
5-C CE NT RA L M4E1;1%041 rci
FIGURE 57
middle of the map sheet and truly proportioned latitude intervals
stepped off along it. The arc of the standard parallel is de-
scribed with radius as above, to establish point (A) on exten-
sion of the central meridian. Each parallel is drawn as an arc
from this point to its correct intersection with the central
meridian. Longitude intersections are truly and thus equally
spaced along each parallel. Meridians are drawn as curves
through identically numbered longitude points on succeeding
parallels. The result is a winged-shaped network base for an
equal-area map. AS you study Fig.- 57, you will realize that
the network would get entirely fantastic if it were extended
to cover the world.
Obviously, on the Bonne projection, shapes are not con-
formal, but arereasonably correct near he central meridian.
Distances are true along the central meridian and each parallel.
Directions are true along projection lines but Ilot between them.
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Thus, the projection is well suited to areas of considerable la-
titudinal extent and can be used to include continents as wide
lgagiltUNilminy,as auraiia. No projection will provide complete
socuracy for this large land mass so the Bonne is often used be-
cause the curved parallels and meridians come closer to right-
angled intersections than is the case on many projections. This
,relationship creates less distortion of shape and retains the
equivalence of area sought in depicting many distributions where
direction and absolute conformality are not essential.
The Bonne Projection can be identified by the following
characteristics. All parallels are arcs of concentric circles
emanating from a common point beyond the pole and cutting the
central meridian at truly spaced intersections. All meridians
are flattened curves except the central meridian which is a
straight line. Intervals between longitudes decrease toward the
polar point but are equally spaced along each parallel.
Poluonic
There is always good correlation of earth and map details
along the line of tangency, as we have observed in previous ex-
amples. Since accuracy is the objective of mapping, why not in-
crease the number of tangent points by utilizing many cones in-
stead of one? The best results, in answer to this question,
would be obtained by drawing an infinite number of cones tangent
to a, basic globe at fractions of one degree apart. Drawing such
an illustration would unfold only a plethora of lines. Fig. 59
will demonstrate the principle, however, with a few cones placed
15 degrees apart.
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POLYGONIC PAOJLCTIoN
COIN4E5 TA NG E NT 41T
15 ? Te ftvoc.5
HE
AS'
FIGURE 59
The polyconic projection is constructed from a central verti-
cal along which latitude intersections are truly spaced. Non-
concentric circles are described from these points with a radius
equal to the length of the basic cone from its point of tangency
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to its apex. This fixes the center for each circle at successive
(not common) points on the extension of the central meridian. The
equator is kept as a straight line. Meridian intersections are
truly spaced along each parallel and connected by flattened curves
from the pole through these points.
The resulting projedtion is a compromise which approximates
but does not have any of the desired characteristics of a perfect
map. Increasing the number of tangent points is offset by the
scale error and distorted relationship of parallels to meridians
away from the central meridian. Al], details are badly distorted
on the outer edges if the projection is developed to include a
hemisphere as can be seen on Fig. 59.
The polyconic projection was devised by Ferdinand Hassler,
first director of the Coast and Geodetic Survey, in 1820, to fit
the mapping needs of the essentially coastal-bound United States.
It was well suited to this purpose because of the largely north:-
south orientation of the states. Quadrangles based on this pro-
jection can be fitted together for any distance north-south, pole
to pole if necessary. East-west quadrangles.away from the central
meridian will not fit. Possibly the only reason this projection
gained such popularity was due to the fact that complete tables
were worked out for the world based on polyconic computations.
These tables made construction of sheets comparatively easy. Most
of the quadrangles of the Geological Survey consequently have been
based on the Polyconic which is as good as any conic projection
fo* small areas but is questionable for large area coverage.
Special characteristics are difficult to recognize on U.S.
60
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Topographic quadrangles that are normally less than one degree
in extent. In this interval both parallels and meridians curve
so slightly that they are treated as straight lines. Furthermore,
lateral distortion is slight when individual sheets are developed
from rather closely spaced central meridians. On maps of larger
areas, the projection can be recognized by the straight-line,
central meridian and equator, and by the non-concentric parallels
and flattened curved meridians which intersect each other at
increasing angles and distances away from the central meridian,
but are equally spaced along any given latitude or longitude
line.
* Modified Polyconic
The modified polyconic is included in this appraisal of
projections because it was adopted for the International Map of
the World series discussed in the next chapter. The modification
consists of making the central meridian scale a fraction smaller
than it should be, causing the scale to be true on two separate
meridians, 20 on either side of the central one. Scale is kept
true on the bounding parallels which are constructed like those
for the Polyconic. These bounding parallels are divided truly
and meridians are straight lines joining the corresponding points
of the top and bottom parallels.
When the conference members were debating the merits of
projections for the TM, they disapproved the Polyconic because
the curved parallels and meridians would not permit a number of
sheets to be fitted together. (Individual sheets are 40 x 60
to latitude 600 and mar be 4 x 12? poleward from 600. Inclusion
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way U. S. Topographic quadrangles do.) Consequently, the modifi-
cation was made to the Polyconic so that every sheet edge Sits ex?
actly with the corresponding edges of its four adjacent sheets..
More than five sheets will not fit perfectly. Fig. 62. Obviously,
the projection was not intended for and is not adaptable to a
single map of the world.
Fit of Modified Polyconic Sheets of
International Map of the World
, FIGURE 62
=midge
If the Bonne projection were made tangent at the equator, it
would have the same characteristics as the Sinusoidal projection.
This projection is easier to understand, though, if its development
is explained in another way. To do this we can elaborate on the
brief explanation and diagram given on page 43 illustrating equal-
area and non-conformality. The equator is laid down as a straight
line drawn in correct ratio to the length of the earth equator. A
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central meridian of true length is erected at right angles to the
equatorial line. Straight lines are drawn parallel to the equa-
tor and spaced at true latitude intervals along the central meri-
aut. The total length of each parallel is in true proportion
to its earth distance which can be obtained by taking the length
of the equator line times the cosine of the angle of the lati-
tilde. For example, the cosine of 600 is 0.500 or in other words,
the length of the 60t4 parallel north or south is the length
of the equator. True longitude spaces are stepped off along
each parallel. Meridians are drawn as flattened (sine) curves
through the points established on each parallel to meet in a
point at the poles.
By construction, the projection is equal area. Distances
are true along each parallel and the central meridian. Directions
are true along projection lines. Shapes are compressed in polar
areas because of the rapid convergence of meridians toward the
polar points and are greatly distorted toward the edges of a
hemisphere or world map network in response to the elongation of
meridians along the periphera. On the other hand, shapes are
reasonably good in equatorial areas to 400 poleward due to the
slight decrease in the lengths of parallels around the bulge of
the earth in this zone. The Sinusoidal projection, therefore,
is best suited for mapping near a central meridian or in lower
latitudes, although it is used for world distribution maps be-
cause of its equivalence.
Distinguishing characteristics are the equally spaced
straight line parallels intersected by curved meridians which
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are equally spaced along each parallel but converge to a point at
the poles. The overall appearance of this projection somewhat re-
sembles a top.
All of the preceding projections can be explained or i4us-
trated by the relation of cone to globe even though historically
it is known that many of them were developed purely by mathematics
without recourse to the cone concept. Later attempts at simpli-
fication brought out the conic relationships. The next few pro-
jections have never been resolved beyond the mathematical stage,
but can be simplified in explanation.
Homolographic
Molleweide is given credit for the homolographic projection
although others produced similar results. Homolographic means a
proportionality of areas on the globe with corresponding areas on
the map. The main idea is to open out a sphere sq as to have not
only the whole earth on one map, but,aloo to have given areas the
same as their corresponding areas on the globe. To achieve this,
Molleweide cemputed the area of a hemisphere and then of a circle
encompassing the same area. Next, he added the area of a hemi-
sphere on each side of the circle to form an elipse. Fig. 65.
When we construct the Homolographic graphically, the equator
is twice the length of the diameter of the constructed circle, or
central meridian. The area enclosed between consecutive parallels
is computed by the law of equal surfaces, and straight lines are
constructed perpendicular to the central meridian to enclose a
comparable area on the elipse. Parallels, therefore are not
equally spaced but occur, rather, at decreasing intervals poleward
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polar points in much more flattened curves than the rounded Homo-
lographic meridians. Consequently, there is always a change in
the curvature at 400. Study Fig. 70 to confirm this point. All
the other recognizable traits are the same as those for the two
contributing projections.
Van Der Grinten
Another oval-shaped projection can be obtained by lopping
off the polar areas of the circle based Van der Grinten projec-
tion that is used for some maps of the world. The basic pro-
jection is evolved from a circle whose area is equal to that of a
globe of one half the diameter of this circle. The central med.-
%
dian and equator are straight lines. The central meridian is
VAN DER GIT
45
FIGUaE 67
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unequally divided into parts of 180? from pole to pole, while the
same diameter representing the equator is equally divided into
parts of 360? (Fig. 67)
This projection is neither conformal nor equal-area and has
no properties of scientific value. It does present a fair uni-
formity of shapes and less distortion than some equal-area pro-
jections and so is adequate for imparting pictorial impressions.
Interrupted Projections
No one, uninterrupted map of the world can be both:conformal
and equal area. Shapes, however, are found to be most nearly
correct near the central meridian of equal-area world maps and to
become more distorted the farther they are removed from it. A
large number of interruptions can be used to correct this fault
at the expense of unity and readability. Since no spherical print-
ing presses have as yet been prefected that are commercially
feasible, maps for world globes are usually printed as gores on
flat paper and then fitted to a sphere. Polar areas are printed
as small circular maps that cap the gore-fitted globe. Fig. 69
illustrates how the globe map looks. Extreme segmentation of the
earthls surface features makes it impractical for use as a flat
map. The principle can be followed however, by using a number of
central meridians selected to minimize interruptions of the de-
tails to be shown. In other words, interruptions can be made to
occur in ocean areas if continuity of land masses is desired or,
vice versa. If both land and water distributions are to be shown
at the same time, the choice of an interrupted projection is an
unsatisfactory one even if it is justified on the plea of economy
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VIA& \-il \11 \d1
AIItli
,
FIGURE 69
of space or interrelationship of patterns.
Usually when improvement of land shapes is desirable, lone..
tude lines that come nearest to the middle ofeacheontinent ex".
cept Eurasia Are selected as central meridians, No one central
meridian can lessen shape distortion on a land mass as wide**,
longitudinally, as EUrasia. As a raanit,, a apmprop4peipslist be
reached that usually favors Eur0/09- 111 actuslity since pxopeis
. .
the sMaller but more psportant p,art of the, Europe?Asia?Complex.
69
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NOTE DEFLECTION OF MERIDIANS AT 40th PARALLELS'
FIGURE 70
Interruptions have been introduced on many of the world pro-
jections which show the equator as a straight line but those Most
commonly seen are Interrupted Sinusoidal, Homolographic or Homo*
losine.
Mercator
One projection for world mapping that has enjoyed long and
Continued popularity is neither interrupted nor equal area.
Gerhard Kremer, whose latinized surname becomes Mercator, de-
? veloped his famous projection for the benefit of 'Sailors of the
Sixteenth century who had limited navigatichal-equipiment with
. which to plot and keep: on their intended course... These
navi-
gators needed a map or sailing chart on'which they could lay
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their courses with nothing more complicated than a straight edge.
Mercator made possible the straight rhumb line by the method
shown on page.45 A thuMb line is a line that crosses each
parallel and each meridian at a constant angle. It mar become
complicated to plat if it develops as a spiral or curved line
in r6sponse to the peculiarities of many projections.
? Although the Mercator projection can never be projected,
since it is mathematically computed, it was inspired by the idea
of a cylinder tangent at the equator. Spacing of parallels is
worked out mathematically from the basic cylinder to globe re-
lationship. A horizontal line is drawn in correot ratio to the
globe equator. Meridian intervals are stepped oft truly along
this Equator line and parallel meridians erected perpendicular
to it. Instead of allowing the parallel spacing to fall as it
would on a gnomonic- cylindrical projection, each is spaced in
proportion to the increasing meridian spacing distortion pole-
ward. Such proportioning makes intervals between parallels less
exaggerated than the gnomonic cylindrical, but, nevertheless,
makes the projection impractical for mapping poleward of approxi-
mately 75 or 80 degrees and impossible for polar areas. In the
days of Mercator, this weakness was not critical since little
was known of polar areas, and they were not involved in the navi-
gational business of the times. How times have ohangedl
AlmoSt every educated person has heard of the shortcoming's
of the Mercator projection for a world map. Overall areas,
1. For a definition of Gnomonic, see page 79
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shapes and distances are increasingly enlarged away from the equa?
tor. Critics of the projection are always quick to point out that
many false Concepts of the comparative sizes of land masses are
due to the widespread use of the Mercator in classrooms. Then in
MERCATOR PROJECTION
Latitudes WO south to 78? north
11
?
.1e
III.
11
0
1
III
I
al
1
1
180 165 150 135 120 10590 75 60 45 50 15 5
FIGURE 72
78
15
eo
41-5
30
15
15
30
45
60
45 60 75 90 OS 120 135 150 165 180
the next breath, they often suggest. substituting a polar projection
which you will soon -see is just as false in -a different -way. The
truth of the matter is that inadequate teaching and explanation are
at fault and not the projections. True shape and, spatial and
size relationships among continents can only be acquired from a
globe. Even the globe medium has a limitation. Because of spheri?
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city, the whole world cannot be viewed simultaneously. In this
respect, ,a Mercator based map is superior. It shows the whole
world on a simple network that retains directions and relative
positioning of continents except in respect to the poles. Learn
its limitations and appreciate its advantages before you are
tempted to join the antagonists or protagonists of any projec-
tion.
Study Fig. 72 and do your own listing of the recognizable
characteristics of a Mercator projection.
Transverse Mercator
Thus far, we have been examining projections that are tan-
gent to or developed from a parallel of latitude. There is no
reason, however, why a longitude or even a diagonal line might
not be used. Although this is not a new idea, it has gained
its greatest popularity in the present century. The English
and other European map makers had used the Transverse Mercator
for several military map series before its value was finally
appreciated by U. S. map makers. By international agreement a
slight modification of the standard Transverse Mercator pro-
jection was adopted in 1948 by many of the allied nations for
military mapping of the world.
We will consider the standard transversing first, and then
the adopted modification. A Transverse Mercator can be con-
ceived upon but not developed from a cylinder tangent at any
given great circle except the equator. Except in special
cases, tangency is fixed along '?reat-circle formed by two
opposing meridians as shown in Pig. 74. It is not the Equator)
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RELATIONSHIP OF BASIC CYLINDE.6 TO GLCBis
-A.
R SVER5E MERCATOR
CYLINDER AXIS t Qact T OR
IDCNTICAL.
FIGURE:74
on a Transverse Mercator, therefore, which is true to _scale and
correctly divided, but a central Meridian. Just as the Equator
is the only line true to scale on the ordinary Mercator, .the cen?
tral meridian is the only line true to scale on theTransverse
Mercator. Al]. parallels except the equator are curved and their
lengths, while not -exactly true to scale, do decrease poleward.
The poles, which cannot be represented on the Mercator because
the polar axis is parallel to the plane. of the cylinder (Fig.
74A), can be ehown on -a Transverse Mercator since they are in
the plane of the tangent line, Fig. 75. Distances between
meridians increase outward from the central meridian in either
direction toward higher numbered meridians. The intervals in?
crease in the same ratio as latitude intervals increase pole?
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ward on the Mercator. Meridians converge at the poles and are curved
lines except for the straight meridian. Parallels and meridians inter-
sect at right angles to aid conformality. Distortion of distances is
relatively slight near the tangent meridian. The projection serves
therefore, for mapping belts that are narrow longitudinally and wide
latitudinally.
TRANSVERSE MERCATOR
? .
10 70 00
00 TO 00 50 40 , goittlot
-----
....
1
,
imperative that maps used for these purposes be conformal and
also provide accurate distances. It was found that maps approach-
ing this ideal could be created by modifying the standard Trans-
verse Mercator Projection. Such modification is achieved by
assuming a secant rather than a tangent cylinder. When the
inder is tangent to a globe, the radius of the cylinder is equal
to that of the globe resulting in no distortion of mapping along
the central meridian (tangent line). Thus, distances and shape
are true along this line and are distorted eastward and westward
75
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from it. In projecting military maps, the axis of the cylinder is
identioal with the equatorial. plane. (Fig. 74B). The Cylinder is
made elliptical in dross section so that it cuts through the glebe,
as in Figure 760 along two lines parallel to the central meridian.
Seale is true along these two Meridians and the rest of the projec?
tion is manipulated mathematically to equate the stretch in longi?
tude with that in. latitude.. No attempt is made to project the
MILITARi TRAN4VLASE MSRGATOR
Fimas 76
world as a whole on one sheet. Instead, the project is broken into
zones, each with its own central meridian. A special military frame-
work has been devised to facilitate the use of this zonal mapping.
Refinements of the framework are discussed in the .next group of map
ingredients called grids.
The Transverse Mercator Projection is used for military mapping
76
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between 80 north and 800 south latitude at any longitude. Be-
cause of the special characteristics and requirements for polar
maps, another projection was adopted to complete world mapping
in the areas from 800 to the poles. This Polar Stereographic
leads us to the third type of graphic presentation of projec-
tions, those based on planes, which we will discuss briefly
before concluding with the projection in question.
Azimuthal Projections
tOMM???????????????
Arty nbtwork that can be presented graphically by projection
from globe to plane has only one point that touches the assumed
globe, (Fig. 44). Directions are true from this point at any
angle. They are not necessarily true from other points. All
directions measured in terms of angles from a given point are
called azimuths. Hence the name AZIMUTHAL is assigned to plane
projections emanating from a given point. The given point of
origin may be the poles or any other selected place. Many in-
teresting maps have been developed to show an important city
as the liprojectionn pole or center of terrestrial activity. .
All directions can be measured truly from this city to any
other rival or complementing city in a manner similar to using
spokes from a hub.
In the simplest azimuthal projections, all meridians are
straight lines radiating from the point of tangency and are
equally spaced along given parallels. These parallels are
spaced in relation to where rays from a source of light cast
shadows of latitude lines on the plane. The light could be
placed anywhere, but four basic placements will illustrate the
77
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principle. Figure 78 shows these placements and the relationship
of light rays to plane. For purposes of demonstration, only one
A
GNOMONIC
row own. sumo woo.
Source of light at intinit
makes all rays parallel*
ORTHOGRAPMC
EQUIDISTANT
Plane of projection
HIC
FIGURE 78
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ie cVnaa;essVO.re
point of tangen4 is a pole. Ticks on each globe represent true'
lattUde spacing along theCircUmference.
GnoMenic.- The source of 'light ie_attne: Center of the globe
gtdmen, This Greek name may have been derived from mythology.
Something was responsible for internal disturbances that the
ancents observed. Since there had to be an explanation tor every-
thing and the scientific geologic one of volcanism and diastro-
phrism, had not been expounded, the Greeks invented a group of
people called gnomes who inhabited the center of the earth and
pushed the earth's crust around!
These same gnomes push latitude projection lines far away
from their true spacing as can be seen on Fig. 78A. Stretching
inereo,5es ,so rapidly away from the point of tangency that it
???...,...p? .?????.
becomes impossible to project 90? away from the point. If ex-
tensions of light rays are constructed accurately, the 90? ray
would be parallel to the plane of projection and so would never
touch it.
ste/magslois. - Some distortion of latitude intervals can
be eliminated by placing the light at the antipode or point on
the circumference 180 degrees removed from the plane of projec-
tion. Spacing still increases away from the point of tangency
but the distortion is not so great. Projection of 900 falls
well within the limits of a plane of reasonable length and points
nearly 180 degrees away can be drawn if the plane is extended an
unreasonable distance. These relationships are shown on Fig. 78D.
- Placement of light conforms to the sun-earth
79 -
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relationship in orthographic projections. The sun is so far re-
moved and so much larger than the earth that its rays strike the
earth perpendicular to the plane of projection. Notice in Fig.
78C that the spacing decreases away from the point of tangency
which is the reverse of the previous two, It is apparent that
only 90 degrees on either side of the tangent point can be pro-
jected from such a source of light.
Equidistant - Instead of having latitude spacing increase
or decrease away from a point, it can be equally but not truly
spaced by rigging the saurce,df:light. Figure 78B shows the light
in a predetermined position by which the distance between it and
the axial point on the circumference is equal to the radius of
latitude 45. Graphic derivation of the distance at which to place
the light for Equidistant projection is included in Fig. 78C.
It should be noted that sources of light can be applied to
other than planes. This was indicated in the explanation of the
equatorial aspect of the Mercator evolved from a gnomonic cylin-
drical concept. Furthermore, azimuthals, like other types of
projections, can be devised mathematically. These are impossible
to reproduce or illustrate by reference to a source of light cast-
ing shadows of a network of global lines on a developable surface.
Only two azimuthal projections are to be given as examples.
Explanations for other more complicated types will be found in
texts dealing primarily with projections and not heading deli-
berately in the direction of using projections as one ingredient
in map reading.
Polar Gnomonic
The Polar Gnomonic projection is widely used for navigation
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The choice of projection is not especially critical for map
sheets covering a small area if the projection is carefully and
accurately constructed in relation to this area. Even the ex-
perts will admit that it is impossible to recognize the projec-
tion used on very large scale map sheets.
When the area to be mapped extends over considerable lati.
tude and longitude the choice of projection is critical and must
be made on the basis of the properties that are most essential
to good depiction of the entity to be shown and the purpose for
which it is to be used. Letts take distance (scale) as one
case in point. Distances can be made correct along 1) all meri-
dians and one or two parallels, 2) along all parallels and one
or two meridians; they cannot be correct along all parallels and
all meridians. If a conformal projection is chosen, then if scale
along a given parallel is too great, scale along its intersecting
meridians will also be too great. If an equal-area projection
is chosen, then if scalealong given parallels is too great it
will be too small along meridians. The choice among equiva-
lence, conformality and azimuthality throws out some other
property, especially or small scale maps covering a large area
such as the U.S., the U.S.S.R., Africa, or the world, and so
it goes, since most human activity is a compromise with per-
fection.
Mgit46. Grids
From Graticule to Grid
In all of the above discussion, any organized network of
latitude and longitude lines, regardless of whether they can
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be projected or not, has been called a projection. Some cartogra-
phers, however, would object to this since they prefer to differ-
entiate the projectable from the non-projectable varieties by
calling the latter grids. Addition of the term "military grids"
leads inevitably to confusion with this method of grouping pro-
jections. Personnel at the Army Map Service and many other map
makers and users, consequently, have decided to call any orga-
nized framework of latitude and longitude used for maps, a
GRATICULE. The necessity for determining the mechanics of the
map network derivation is thus eliminated. Furthermore, a re-
ference intended to mean geographic projection will not be con-
strued to mean MILITARY GRID or simply GRID.
Reasons for Two Frameworks
Representation of large sections of the world on a rec-
tangular graticule would violate most of the criteria for an
accurate map, and would distort earth features beyond usefulness.
In order to represent an area with a minimum of distortion, the
graticule is therefore adopted first :(earth features to be mapped
will be drawn to conform to this framework). After the projection
is selected, some spot on it is chosen as point of origin and some
direction indicated for orienting thy military grid. A GRID is
a rectangular system of coordinates composed of two sets of paral-
lel lines drawn at right angles upon a plane map surface. This
grid is superimposed upon the map graticule and extended over the
entire area controlled by the graticule. A definite relation-
ship then exists between any grid intersection and any adjacent
intersection of latitude and longitude. The grid system is used
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in sealing distances determining directions and locating points.
Although any convenient unit of linear measurement can be adopted,
yards and meters are most commonly employed on military grids.
1;42..0.12,.g Points
Accurate locations can be given in terms of geographic co,..
ordinates, Any high degree of refinement in pin-pointing an
objective, however, requires a lengthy enumeration of letters
and numbers. For example, the exact geographic location of the
Lincoln Memorial in Washington, D.C. is 38053'20.221T. L., 770
03102.199M.
Translation of this long list of numbers to or from a grati-
cule would be complicated. It would necessitate the inclusion of
more latitude and longitude lines than are normally found on a
finished map;. Attempting to interpolate the site of the memorial
between more widely spaced lines would be inadequate on those
graticules on which intervals between parallels and meridians
are not uniformly correct.. A map reader can locate the Memorial
more quickly and accurately by using the military grid. Each
grid interval is the same as any other interval on the same sheet.
Interpolation between the grid lines can be done with a ruler or
even the straight edge of a piece of paper.
Locating objects on a grid is accomplished 1* a set tech-
nique which does not vary from map to map, or hemisphere to
hemisphere. This technique is always to begin in the southwest
(lower left-hand) corner of a sheet and read the coordinates
? to the right to the desired distance and then up along this
line to the point being located. In short: READ - RIGHT - UP.
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The map sheet showing the Lincoln Memorial is not available
to you, but one of the Hagerstown series will do just as well to
illustrate how to apply the above technique. On Hagerstown Sheet
5463 II NW our objective Will be Rockdale School. (To make you
more appreciative of the efficiency of locating Places'bYgrid
references, try to find this school by the "search" method. Then
see how much simpler locating places can be When you fallow the
grid technique.) There are three different Sets of grid numbers
printed in black, blue and brown on this sheet; the fourth set of
values in the margin represents geographic coordinates. Black
numbers are UTM grid numbers; the blue, the overlapping UTM grid;
and the brown, U.S. Polyconic. All of these will be explained
later. Now we will be concerned with only the black grid numbers.
In the lower left (SW) corner find 264000m E. Read RIGHT
along the lower margin until you find 267 from which the three
small zeros 000 have been atitted:for,-convenience. Read on .9
of the way toward 268. Keep your finger on this estimated spot
and refer back to SW corner to read the first full grid line UP
from the corner which is4390 000m a continue to read up until.
you arrive at 4400. Estimate .9 of the distance beyond this
number toward 4401. The Easting (reading right) is 267.9 and the
6 ?
Northing (reading up) is 4400.9. In writing these grid coordil-
nates the elevated numbers and decimal points are omitted and
all figures are written as one unit with the Easting part of the
coordinate first, thus: 679009. There is Rockdale Schooll Note
that the terms Easting and Northing arise from the fact that read-
ing is relative to the fixed southwest origin for map sheets of
88
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any area in the world.
Giving Directions
So long as two places lie on exactly the same graticule
line, giving direction between them is easy since only one of the
four cardinal points of the compass is involved. When map di-
rections involve "boxing the compass", they become less defini4-:_
tive and tend to be confusing to the average map user. Further-
more, you recall that there are types of projections upon which
diagonal directions between coordinates are not true to earth
directions.
When a military grid is used as the basis for giving di-
rections, many of these complications and inaccuracies are
averted. In describing the position of one point on a gridded
map with reference to some other point (origin to objective)
the azimuth system is used. An AZIMUTH is the angle formed
between two N-S lines passing through-the center of the given
origin and objective. (These lines may be magnetic, true or
grid north lines, of which more later.) The azimuth determines
the direction and is used instead of the compass points in givi.
ing direction.
The procedure for determining azimuth is shown graphically
on Fig. 90A on which it is assumed that the parallel lines re-
present grid lines "lifted" from a map. To determine the di-
rection from origin (A) to objective (13) draw a straight line
(X) between the two points and extend it to the nearest grid
line (26). Orient a protractor with its 0 on the grid line and
it indicator on the intersection of the grid and extended lines.
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OZ
431-410,
LINES
90A
A. Determining direction
from a grid with a
protractor.
01 ?
25
aezeci iv E
ON
B. Azimuth interpretation
of compass readings.
_FIGURE 90
Read the protractor clockwise to the point where the extended line
meets the protractor (Y). The number of degrees read at this point
is the azimuth (202) or direction from A to B. Figure, 90B illus-
trates how the azimuth $ in this case 2021 is the key to giving
directions without having to spell out that B is south by-south-
west by south of A.
No other manipulations are necessary in using azimuths on A
map. Whenever grid azimuths are used with a compass in the11411$
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they must be adjusted to magnetic north to insure proper inter-
pretation of compass readings. Such adjustments are accomplished
by use of declination data explained later in this chapter.
Giving soldiers instructions in compass directions could be
disastrous. By the time a beleaguered soldier had interpreted
the lengthy notation and applied it to a graticule to get his
bearing, the enemy might have spotted him and made any further
use of the map unnecessary. With aid of a compass and the
military grid hewould need less time to determine his position
and head in the direction of safety as you can now readily see.
A word of caution is probably not amiss at this point.
Zero azimuth is not always north. Azimuth is often taken from
the south.point on land and from the north point on sea. Thus,
the diagram on the preceeding page might be a sea azimuth, and
the land azimuth for the same problem would be 22 which is equi-
valent to the back azimuth in the first case. (202-180= 22)
A comparison of terms reveals that they all mean the same
thing, direction. You would probably ask for direction; a
soldier or astronomer would ask for azimuth, and land surveyor
would ask for bearing. Bearing and azimuth mean the same thing
to 9001 since azimuths are measured in terms of a whole circle
and bearings in terms of a quadrant of a circle. The answer
shown on Fig. 90B might look something like this.
By:. The Average Man Southwest
Marjners Compass South Southwest by south-SSWS
Suvvaaera Bearing 3 22?W
Land azimuth 22
Sea azimuth 202
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Translating Distances
Unequal spacing of graticule intervals, inadequacy of one '
bar scale for an entire sheet and many other weakneses arising
from geographic determination of distances also make the grid
a useful complement of the graticule.
Grid spacing, of one thousand and ten thousand yards or
meters depending upon the scale of the map, creates perfect
squares of equal size over the entire map. These squares can be
subdivided into smaller units by inspection or through the use
of a straight edge. All distance values remain constant and so
diagonals can also be drawn and distances measured along them.
Short distances can be given in terms of parts of units. Such
measurements are important for local operations. An added advan-
tage of grid units over geographic units is that the latter must
be converted to distances by means of tables while grid units re-
present distance and so require no conversion.
Military Grid and Grid Reference Systeme
Universal Transverse Mercator Grid-
To achieve a comprehensive and uniform coverage of the world,
several agencies and countries have adopted a common military grid
system. For example, United States military large and medium scale
map series covering the world are being constructed on or converted
to the Universal Transverse Mercator Grid system (UTM). This
system is based upon the Transverse Mercator Projection. Deriva-
tion of coordinates for the projection is based upon computations
for a given spheroid.
The military Transverse Mercator Projection as you remember
9
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from the previous discussion of it (see page 73) is used in zones
60 wide. The longitude of origin for each zone is the central
meridian which is arbitrarily numbered 500,000 and is called a
FALSE BASTING (labelled E). False easting numbers are assigned
to each vertical grid line with their values decreasing toward
the westepn and increasing toward the eastern limit of each
zone. Zones are numbered from east to west around the world be-
ginning with 1 at 180 to 174? W and increasing eastward to 60
on zone 174 to 180? E. Each zone is bounded by meridians which
are multiples of six degrees W or E of Greenwich. At the junc-
ture of one zone with another an overlap of approximately 25
miles of one grid over the next is made on maps to insure
accuracy of correlation.
Because of the secant character of the graticule, scale
factors must be employed when longitude distances are being
computed for projections or when grid distances are converted.
to actual East-West distances for precise control of artillery
firing. The reason for these scale factors is shown in Figure
94. The ordinary map user, however, need not be concerned
with scale factors in giving or using grid references.
The latitude of origin in all zones is the Equator. FALSE
NORTHING (N) numbers are assigned to latitudes beginning with
0 meters at the Equator for the northern hemisphere and with
10,000,000 at the Equator for the southern hemisphere. These
numbers increase in value from the origin to the latitude
limits of the UTM which are 80? N and 80? S.
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Approved FKREtelm8914feWtAlpiatRS)A38010143A000300050001-1
1
1.0011'
Scale
Too
Large
Scale Factor
0.9996
Scale Scale
Too . Too
Small Large
1.
60
43
Grid and Secant Projection Lines Coincide at A 81: B
FIGURE 94
- Spheroids - You have just been introduced to the LIU Grid.
Now you must meet its partners, the Spheroids.' Each spheroid.
controls the business of dispensing coordinates for a particular
area as shown on _Fig. 95. The ideal, of course, would be to have:
the whole world based on one spheroid. Strides are being made in
this direction with the International Spheroid. At present, how-
ever, five spheroids are used because regional surveying, for
+NOON
-1A spheroid is an geometric figure describing the size and
shape of the earth developed from measurements of the earthts
surface. Accepted spheroid figures are used for computation of
all exact projections but were not introduced in the section on
projection because they would have added little then, but are now
essential to the UTU grid explanation.
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> 73
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c)
GiID ZONE D-iJIG TIuNS OF THE MILITA3Y G4D RSFER3NOS LinTE. THE DE6IGNATIL,NS IuwrIFy
_& THE PoLAR ham.$ AND 6GE.-4, BY 8?N.-6. DIVISIONS UF THE GLOBE B4 80%. AND 80?S.
04
01
1
i
1 has been adapted t9 one of the spheroids. Selection of these
t.
1
1 spheroids is based on the fact that the men who did the original
i
1
e *tip rtived-folyRsil e:azie-200=4/1181tiCIAar0P50,11A333A00j1300050001-1
?
. , .
computations of them produced more precise results in one area
?
-
than in others of the world. Subsequently volumes of tables were
coMpleted to sive fizures adjusted to each spheroid. Since the
computation of spheriod tables is a lengthy process
'
existing
tables are being used for the best portions of each Of the five
spheriodS until hew 'tables are completed for the International
. ,
used for finding and plotting grid
' Spheroid? These tables
coerdlr,,e,t,e0,
1 eXid
are
pic convergence of meridLins
impractical for ,
near the poles makes the UTM
reason 4 arid
Tc'T areas?
For this
basa on a pr jJ:cticn i prcerTolo,
Piti:cr is :o cork en; )rc1l866't
based et tlo -Internanal Spheruid.
The Univol Polar Sterc.ographic Grid (UPS) adapted to this
pro
CT:A-
the poles and is
s wprld coverage in combination with the UTM
POilr are2,3?o sfmpay divided into two parts by-the 180o
and 00 r!cridirs
dinar:,/ use,
based
n Greenwich, Scalp factors are available
but again '4-ley are unnecessary for -
or?
u:f
e
arz ernce System
?
.The UTM or UP5 Grici is all that is necessary for reading
single map sheets b'Jt reference to specific sheets and areas
ceeeittes a reference system Numerical grid references_alone
96
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II
Ii
fl
II
Avi
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might be interpreted to mean 120 places in the world as a result
of similar numbers in 60 zones and 2 hemispheres in the UTM arid
system. Thus, the Military Grid Reference System is designed
for the MU .12-41 UPS srids.
For cOnvenience in using the Reference System, the world is
divided into large, regularly-shaped, geographic areas each of
which is given a unique Grid .Zone Designation. Between 80? 3
and 80? N the world is divided into areas 6? east-west and 8?
north-south. The columns, 6? wide, aligned from west to east
are identified by the UTM zone numbers from 1 to 60. The rows,
8? high, aligned from south to north are identified by letters.
Starting at 80? South and proceeding northward to 80? North the
rows are lettered alphabetically beginning with C. through X and
omitting I and 0. Reading RIGHT UF the combination of the
column (zone) number, i.e., 3, and the row letter, i.e., P,
gives the Grid Zone Designation, 3P. -Fig. 98.
These areas are further subdivided into 100,000 meter
squares based on the grid covering the area. &oh aeuare is
identified by two-letters called the 100,000 Meter Square
Identification. This identification is unique only within the
area covered by the Grid Zone Designation. Anyone using this
Identification must, therefore, be careful to include the
proper Grid Zone Designation. Numerical references within the
100,000 meter square are given to the desired accuracy in terms
of casting (E) and northing (N) arid coordinates. For the
sample point given on Hagerstown, Sheet 5463 II N.W., the Grid
Zone Designation is 18 S. The 100,000 Meter Square Iuentification
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UTM GRID ZONE' DESIGNATIONS
FIGURE 98.
(opposite)
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APPENDIX A
180r 1 Mr 2 1 Al 3
6 7
8 II? 9 av 10
11 n 12
13 ? f-APPIPM91,48rgr cQ!ease VP/ Vii./21 028: Ce 1A-11PtloY 714414 454 46814(41484 LAY VP IN Q21, -41 4
4
ZEMLYA
FRANTS.MIOSIAA
45 46 N? 47 48 49 50 51 52 53 , r 54 e 55 ,- 56 , r 57 r 58 50 66
ME,NIAINAMHZGAILyn
BO SHEMIN
OSTROM
ea
see
Ifiltur
Be RISC
AP
36
32
16
16
I
xr.rr.,,
24
21
32
36
AA
UNIVERSAL TRANSVERSE MERCATOR SYSTEME DE NUMEROTATION DES
GRID ZONE NUMBERING SYSTEM FUSEADX DU QUADRILLAGE UTM
AND ET
INDEX TO SPHEROIDS TABLEAU DES ELLIPSOIDES
60
72
Note: A provision is made for a mini?
murn qVerlap area of Me zone
and spheroid junctions. Trig lists will
include coordinate values on both
zones in the overlap area. The over?
lap area N restricted to fire control
and survey operations and does not
apply to grid references. Grid refer?
ences will be ',mt. Strietly to the
zone boundaries.
The boundaries between spherOids
fall on full degrees of latitude and
langitUde.
CI rke 1866
Clarke 1880
Everest
Besse!
I ternational
Note bene: Pour les jonctions des
fuseaux et des ellipsOides, une zone
recouvrement d'un rninimun de
50 milles est pravue. Dans les zones
de recouvrernents, les carnets des
point geodesioues pOrteront les coo,
donnies pour les deux fusee ux. Les
zones de recouvrement ne uervent
que pour l'artillerie et les !eves et ne
sont pas applicable aux relerences
de quadrillage. Cell s?el seront
taes ngoureusernen aux ',mites des
fuseaux.
Les limites entre les ellipsoides se
trauvent sur leS d grds pleins de
latitude et longitude.
A
1 " 2 '" 3 " 4 5 ' 6 7 8 2 9 10 ? 11 " 12 IC 13 ppro edi
(e11ease3
Ii
/0414
IA-
o-- $1,333A00083
44 "' 45 ' 46 ?? 47 '"? 48 ??' 49 " 50 ' ? 51 22' 52 2 53 " 54 " 55 '? 56 '" 57 "2 58 '" 59 " 60
FOURTH EDI TION?AMS
PRwrpo By ARMY MAP BERyl[E, toRp9 OF ENGINEER, 3 53 ,V4255
Approved For Release 2000/04/18 : CIA-RDP80-01333A000300050001-1
is TU ond numerical reference is 688959.
For reference purposes the ?polar areas are divided into two
A
zones by the 0? -- 180? meridians which form a diameter of the
Universal Polar Stereoj.aphic Projection extending from 80? to
the poles. References are made to Y in the western half and to
Z in the eastern half of the north polar grid; and to A and B
in similar relationship in south polar areas. E4CiI is further
subdivided by 100,000 meter square identifications.
It is not necessary for you to digest further refinements
of. this system at present. A com,lete analysis is given in
books devoted to the development and utilization of grids and
grid references.1
ELyamia Gr.id gistem
U.S. 119.14LeDic - The Grid Sytem for Proi:;ressive Ms ;f
the United States is based upon the Polyconic Grid. Older
military topographic maps of the United States show this system
so that even though all new mapping in this category use the
UTM u,rid, you will find examples of the Polyconic ystem still
in use. Furthermore, during the period of transition, both
grids are shown on map sheets as you noticed on the Hagerstown
map sheet used to demonstrate how to read grid numbers.
The United States is divided into 7 zones each 90 of longi-
tude in width with a degree overlap on each side. The
1 '
For precise breakdown of the Reference System, see Army Map
SerVice"Tuchnical_Manual No. 36 Gride,and Grid Referenceb or
Department of the Army TM5-241 to 16-1-233 The Universal Grid
Systems' ' ' ? , .
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overlapping area can be shown on two sets of maps, one on each .
grid system thus making it possible to have progressive maps
for each zone. Although the System is called progressive, it
is actually an interrupted system with the overlap acting as a
stepping stone to the next system of coordinates. Each zone
has its point of origin at a central meridian which is 4i de-
grees from either edge of the zone, but is actually a multiple
of 80 from 73? W due to the 1/20 overlap of zones. (The longi-
tude 73? 1' obviously is the practical eastern limit for the U.S.).
Each central meridian is numbered 1,000,000 on the grid. Values
increase to the east and decrease to the west from the Central
meridian. The latitude line of origin for all zones is 40030' N.
This line is numbered 2,000,000 on the grid. Values increase
to the north and decrease to the south of the standard parallel.
Grid references are identical in each zone.
For complete reference purposes the zones are lettered from
east to west beginning with A for the New England area and bnd-
ing with G on the west coast.
The whole system was inspired by the French Quadillage
System based on the Lambert Conformal Projection and is very
similar to it. Certain modifications were necessary because
.the French system is expressed in grades and metes and the
.United States system in degrees and yards. The diagram on the
following page shows the grid reference system.
100
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...... t
.____7....?... r , .? ,,?. .,,,..
, ...,,,_, ...?,., ,........ _ , ?c1,-_
1 .,. 0, ......-In
-c
, f
I/ 't -1)',
:------17.? . -i-',Ir--'-1---,:'71-7T-7.-1,7 \ 1 l \ X
A.--.1..,---I',El r, '
7 !!! r ,, rf 1,,,,,,,,, , .., i 1 ,,- ' 1,,