MAPPING ACCURACY AND ARTILLERY EFFECTIVENESS

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP79B01709A000400010005-3
• Release Decision: RIFPUB
• Original Classification: S
• Document Page Count: 6
• Document Creation Date: December 12, 2016
• Document Release Date: November 7, 2001
• Sequence Number: 5
• Publication Date: November 3, 1967
• Content Type: PAPER

Approved Far Release 2 00 b1I09f * CIA-RDP79BO17fl.;l
DEPARTMENT OF THE ARMY
OFFICE OF THE ASSISTANT SECRETARY
WASHINGTON, Q.C. 20310
Coir71/LG ' `/ , t 3 : lS
3 November 1967
*Army Dbclass/Release Instructions On File*
Declass ifica''l teasre tthotinsv mfile
The Army, regarded as a weapons system, consists of people,
means for transport and communication, and firepower. To be
effective the Army must know, in considerable detail, the nature of
the terrain over which it operates. Topographic maps constitute the
principal means of providing this knowledge to the field commander.
While maps are important in planning operations and to answer
the questions "Where am'I? ", and "What is over the hill? ";-highly
accurate maps are required primarily because of their importance
as a component in the firepower system of the Army. It is the pur-
pose of this memorandum to illustrate the role of maps in the
artillery system and to assess the value that should be assigned to
map accuracy.
During the past decade, a great deal of attention has been paid
to improving the effectiveness of artillery shells to improving the
reliability and accuracy of artillery systems, and to developing
computers, communication gear, and meteorological measurement
techniques which will permit accurate coordination of fires from
dispersed artillery pieces. Thus, we should be able to bring upon
targets, as they are identified, sufficient artillery fire to neutralize
those targets efficiently. At the same time, much effort has been
given to the development of target acquisition and surveillance means
to permit detection of enemy movements and identification of useful
targets as they develop in the course of the battle.
The utility of all of these developments depends critically on
the availability of accurate maps. Without them, the sophistication
of other elements of the overall weapons system becomes virtually
useless, and the artilleryman is reduced to using his weapons as a
means of locating the target with respect to the firing pieces. It
was because of the lack of precision in maps, the lack of accurate,
rapid, range finding equipment, and the lack of computer facilities
to solve the ballistic problem in the field that the technique of
"forward observer-controlled" fire was developed. This technique
Approved.For Release `2002%(11/(19; : CIA-RDP79BO1709A000400010005-3
 Approved For Release..2QP(.0.1109 : CIA-RDP79BO1709A000400010005-3
Mapping Accuracy and Artillery Effectiveness (Cont'd)
demands the firing of a few "spotting rounds" into the target area
under the eyes of a forward observer simply to determine the loca-
tion of the target, so that multiple tube volleys may be delivered
in what is called "time-on-target" fire.
The effectiveness of time-on-target fire against personnel
depends critically on whether or not the enemy in the target area
has warning. Calculations by the Ballistic Research Laboratories,
based on experimental data for various target postures and various
kinds of artillery shell, indicated that, in general, the vulnerability
of a target may be reduced approximately ten (10) times if the target
is warned of incoming fire and the people in the target area have time
to seek shelter in foxholes. The system of using forward observers
to control fire provides that warning of necessity. If the available
maps are not sufficiently good to permit exploitation of the fire control
system to permit precise delivery of effective first rounds against
targets in known locations, then the ten-fold advantage of surprise is
denied us.
Accurate maps also have a role in the control of artillery fires
where surprise cannot be exploited. In many situations it is important
to deliver artillery fire on en., my units close to our own troops. Under
such circumstances, friendly units under attack will call for artillery
fire to be delivered as close to their positions as possible, even to the
extent of risking friendly casualties to assure effectiveness against
the attacking enemy. The closeness with which such fires can be
-called down depends not only on the accuracy of the artillery system,
but also on the accuracy with which the relative positions of the artil-
lery piece and the friendly unit can be determined. In any case, a
few tens of meters are significant in such operations.
It should now be clear that an accurate topographic map is
essential if our artillery fire system is to function effectively. In
view of the importance of topographic maps, the Army has given
great attention to accuracy requirements in order to avoid asking for
maps better than it really needs and at the same time to avoid accept-
ing significant degradation in its combat potential through maps which
cannot do the job. Translated into units useful for cartographers, the
Army requirements for accuracy of large scale (1:50, 000) maps are
as follows:
Approved For Release 2002101109 CIA-RDP79BO1709A000400010005-3
 Approved For Release OA /O1189r'* CIA-RDP79B01709A000400010005-3
Mapping Accuracy and Artillery Effectiveness (Cont'd)
Horizontal target location accuracy: 25m (CEP) or t 45m
(90% assurance)
Vertical target location accuracy: ? 10m (90% assurance)
The degradation of weapons effectiveness which would result from
relaxing these requirements has been analyzed for tube artillery and
missile systems planned for combat use through 1975 and beyond. The
following examples, for the 105mm and 155mm Howitzers, are illus-
trative of the results of these analyses and have been selected because
these weapons are and will continue to be most frequently used for
direct support of ground combat operations.
When 105mm Howitzers are used against enemy troops at ranges
of a few kilometers, the number of rounds to produce a specified level
of casualties increases by approximately 25% if the current require-
ment for ? 10-meter vertical target location accuracy is relaxed to
? 40-meters. Ammunition for Army 105mm Howitzers in South Vietnam
is presently issued at a rate of approximately 20 rounds per tube per
day, resulting in a 105mm ammunition cost of approximately $150
million per year. The 105mm Howitzer is normally employed for in-
direct, unobserved fire for up to 80% of its targets. In possible 1970-
75 conflicts, up to half of this could be targetted from large scale
tactical maps, with the balance being used for harrassing and inter-
diction fire. If maps of the required ? 10-meter vertical accuracy are
available for locating targets for unobserved 105mm Howitzer fire in
such a future conflict of the present level of intensity, the increased
effectiveness as compared with using maps having -1 40-meter vertical
accuracy, can be valued at approximately $15 million per year.
The 155mm Howitzer is planned as the primary artillery weapon
for fire support at ranges of 10 to 20 kilometers through the mid-1970's.
For 155mm Howitzer battery fire against enemy troops in company-
sized cantonments at these ranges, calculations show that approximately
25% more rounds are required for the same target coverage if the
required 25-meter horizontal target location accuracy is relaxed to 50-
meters. For the current level of intensity in Southeast Asia, 155mm
Howitzer ammunition is being expended at a rate of more than 30 rounds
per tube per day, also representing a cost of approximately $150
million per year. Thus, for this level of intensity and again assuming
80% unobserved fire, half of which is targetted from map data, the
Approved For Release 20 / 7`lsM9 ;'.;CIA-RDP79BO1709A000400010005-3
 Approved For-Release 2002/01/09 : CIA-RDP79B017Q2J 000400010005-3
Mapping Accuracy and Artillery Effectiveness (Cont'd)
degradation in 155mm Howitzer effectiveness can also be valued at
approximately $15 million per year if the requirement for horizontal
target location accuracy is relaxed from 25-meters to 50-meters.
Over and above the dollar values cited, the advantage of surprise
against enemy troops which can accrue from accurate, unobserved fire
can be assigned a significant value in achieving the field commanders'
objectives. Assuming that, on the average, half of the troops engaged
by such fire will be caught in vulnerable postures (standing, as opposed
to crouching in foxholes), the BRL data indicates a factor of 5 increased
effectivenes4 for all such engagements. If a significant percentage of
targets engaged are troops, say 50%, the overall effectiveness of a
dollar spent on ammunition would at least be doubled. To achieve
comparable levels of effect by increasing ammunition expenditures
would cost 2 - 3 hundred million per year, for the example cited. The
real savings are more difficult to quantify - since they lie in shortening
the time required to "win". At Vietnamese expenditure rates, these
savings are measured in billions of dollars per month. The cost of
preparing the data bank from which adequately accurate maps can be
prepared is less than I day's cost of the current war.
The importance of accurate military topographic maps is such
that there is no doubt that an investment of $30 - $100 million to assure
their prompt `availability is amply justified. Attempts to fill the re-
quirement with marginally adequate acquisition means would be to risk
the necessity of doing the whole job over again.
Charle. L. Poor
Deputy Assistant Secretary of the Army (R&D)
Approved For Release 2002/01/09 : CIA-RDP79B01709A000400010005-3
 'O'-' pproved~ &rW"a9s9'21~&bI/O rtii bP'MB h''F89 OdMU60 Ob-3
0 50
VERTICAL -`.CCURACY OF TARGET LOCX ION, 90% ASSURA:;CE
(,METERS)
10-
30
Approved For Release 2002/01/09 CIA-R
~% ~
0'A($1 c:v ^ .
0 1\1
 1051rn 11014ITZER . u : : ' : : d... - u i !1
Approved For Release 2002/01/09 : CIA-RDP79BO1709A000400010005-3
vn'@:1 )on System
1.05i-.an Howitzer, M10 1A1
Ni. Projectile, TNT loaded
C1:ai: ;e 5, 6km range, 29? angle of fall
L thality against personnel:
.Scw-ld ing: 390 square meters
prole: 330 square meters
Crouching
in fog,-holes: 40 square meters
50
100
200
Number of Rounds to Inflict 307 Casualties
Tar et Radius meters
All' Standing
50
100
200
z Prone and 50
? Crouching in fox-holes, 100
200
All Crouching in 50
fox-holes 100
200
Vertical component of Target I~hcation Error, 907 assurance
-1Om
55
70
152
64
82
179
129
166
358
506
656
1448
28 meters (range).
4 meters (der1. ~~~i.e,,)
error, per TARS-75: 25m (CEP)
Allowable target location
Total predicted error: 39 meters (range)
(includes precision, met, etc)17 meters (d(.-flecti,;n)
?10m
?20m
?30m
-+40m
?50m
56
59
66
73
82
71
75
81
89
97
153
156
161
.168
176
66
70
77
86
96
84
88
96
104
114
180
183.
189
197
206
132
140
154
172
192
168
176
191
208
229
360
366
378
393
412
516
542
595
656
728
665
691
739
800
872
1454
1467
1495
1529
1585
tflU r~ ICI':!
i-.T 3 Ya' l':.`-":'ALS
VOD
Approved For Release 2002/01/09 : CIA-RDP79BO1709A000400010005-3