TACTICAL MULTISENSOR RECONNAISSANCE (U) VOL. 2 TARGET CHARACTERISTICS(U)

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP67B00657R000300190001-7
• Release Decision: RIFPUB
• Original Classification: S
• Document Page Count: 84
• Document Creation Date: December 22, 2016
• Document Release Date: May 5, 2010
• Sequence Number: 1
• Publication Date: June 15, 1965
• Content Type: REPORT

Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SwW 8452-65-40
SECRET TM-65-2
SPECIAL HANDLING
COPY NO. _L
TACTICAL MULTISENSOR
RECONNAISSANCE (U)
VOL.2
TARGET CHARACTERISTICS(U)
15 JUNE 1965
SPECIAL HANDLING
SECRET
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.1 The Reason for Tactical Aerial Reconnaissance . . . . . . , . . 1-1
1.2 An Optimum Tactical Reconnaissance System . . . . . . . . . . . 1-2
1.3 Targets for Tactical Reconnaissance . . . . . . . . . . . . . . 1-3
1.4 Target Sensor Matrix . . . . . . . . . . . . . . . . . . . . . 1-8
1.5 The Reconnaissance Cycle . . . . . . . . . . . . . . . . . . . 1-8
2. Reconnaissance Sensors and Their Capabilities. . . . . . . . . . . . 2-1
2.1 Visual Observation . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.2 Photography . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.3 Radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
2.4 Infrared. . . . . . . . . . . . . . . . . . . . . . . 2-4
2.5 Electronic Reconnaissance (FLINT) . 2-5
2.6 Capabilities and Limitations of Remote Sensors . . . . . . . . 2-5
3. Photographic Reconnaissance . . . . . . . . . . . . . . . . . . . . . 3-1
3.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.2 Photographic Scale . . . . . . . . . . . . . . . . . . . . . . . 3-2
3.3 Photograhic Resolution . . . . . . . . . . . . . . . . . . . . 3-3
3.4 Target Characteristics . . . . . . . . . . . . . . . . . . . . 3-9
3.5 Evaluation of Photography as a Reconnaissance Sensor . . . . . 3-11
3.6 Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13
4. Radar Reconnaissance . . , , , , , , , , , , , , , , , , , , 4-1
4.1 General . . . , , , . , , , 4-1
4.2 Imagery Factors . . . . . . . . . . . . . . . . . . . . . . . 4-1
4.3 Foliage Penetration . . . . . . . . . . . . . . . . . . 4-4
4.4 Long Term Activity Detection . . . . . . . . . . . . . . . . 4-4
4.5 Moving Target Indicator (MTI) Factors . . . . . . . . . . . . . 4-6
4.6 Usefulness of Fine Resolution Radar . . . . . . . . . . . . . . 4-6
4.7 Evaluation of Radar as a Sensor , , , , , , , , , , , , , , , , 4-8
4.8 References, , , , , , , , , , , , , , , , , , , , , , , , , , , 4-8
5. Infrared Reconnaissance . . . . . . . . . . . . . . . . . . . . . . 5-1
5.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.2 Target Characteristics . . . . . . . . . . . . . . . . . . . . 5-3
5.3 Evaluation of Infrared as a Sensor . . . . . . . . . . . . . . 5-8
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
CONTENTS (Continued)
6. Electronic Intelligence (ELINT) Reconnaissance. . . . . . . . . . . . 6-1
6.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
6.2 Target Recognition Characteristics . . . . . ? ? ? ? ? ? ? ? ? . 6-4
6.3 Target Location Capability . . . . . . . . . . . . . . . . . . . 6-7
6.4 Signal Environment Considerations . . . . . . . . . . . . . . . . 6-8
6.5 Target Matrix Parameters . . . . . . . . . . . . . . . . . . . . 6-16
7. Target/Sensor Matrix . . . . . . . . . . . . . . . . . . . . . . . . 7-1
7.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
7.2 Matrix Format. . . 7-1
7.3 Quantitative Evaluation. 7-2
SPECIAL HANDLING iii
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
3-1. Three-Bar Resolution Target . . . . . . . . . . . . . . . . . . . 3-3a
3-2. Frequency of Occurrence versus Resolving Power for Film Type
4404 at 2:1 Object Contrast . . . . . . . . . . . . . . . . . . . 3-4
3-3. Resolving Power versus Log Exposure for SO-102 Film, D-19
Development, 6 minutes at 68?F . . . . . . . . . . . . . . . . . . 3-6
4-1. Data Recognition Probability versus Ground Resolution . . . . . . 4-3
4-2. Radar Mapping Capability at Low Altitude (Grazing Angle Effects
Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
4-3. Resolution Required for Target Identification (ft). . . . . . . . 4-7
5-1. Diagram of the Thermal Processes Associated with the Radiance
of an Infrared Target . . . . . . . . . . . . . . . . . . . . . . 5-2
5-2. Transmittance Through the Cloudless Atmosphere versus
Wavelength . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
5-3. Downdwelling IR Spectral Radiance . . . . . . . . . . . . . . . . 5-5
5-4. Wavelength Distribution and Magnitude of Emitted Radiation for.
Certain Targets . . . . . . . . . . . . . . . . . . . . . . . . 5-6
6-1. Radio Electromagnetic Spectrum . . . . . . . . . . . . . . . . . 6-2
6-2. Soviet Radar Disposition (No. 1) RF Frequency versus Pulse
Repetition Frequency. . . . . . . . . . . . . . . . . . . 6-20
6-3. Soviet Radar Disposition (No. 2) RF Frequency versus Pulse
Repetition Frequency. . . . . . . . . . . . . . . . . . . 6-21
6-4. Soviet Radar Disposition (No. 3) RF Frequency versus Pulse
Repetition Frequency. . . . . . . . . . . . . . . . . . . 6-22
6-5. Soviet Radar Disposition (No. 4) RF Frequency versus Pulse
Repetition Frequency . . . . . . . . . . . . . . . . . . . . . . . 6-23
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
S%001 Nof
SPECIAL HANDLING
1-1. Basic Target List . . . . . . . . . . . . . . . . . . . . . . . . 1-4
2-1. Remote Sensor Comparison . . . . . . . . . . . . . . . . . . . . 2-6
3-1. Resolving Power Values for Representative Aerial Emulsion, 1/mm . 3-7
3-2. Targets Characterized by Detail Level . . . . . . , . . . . . . . 3-10
3-3. General Camera Information for Flight Altitudes of 1000 and
30,000 feet at Flight Altitudes of 1000 Knots . . . . . . . . . . 3-12
5-1. Characteristics of Certain Targets . . . . . . . . . . . . . . . . 5-7
6-1. Radar Classification by Function . . . . . . . . . . . . . . . . 6-5
6-2. Postulated Soviet Strategic Radar Environment for Baltic Sea Area
(1967-1970 Period) . . . . . . . . . . . . . . . . . . . . . . . . 6-10
6-3. Tactical Emitters Associated with a Soviet Combined Arms Army . . 6-12
6-4. Soviet Ground Communication Equipment . . . . . . . . . . . . . . 6-15
6-5. Predicted 1967 Radar Environment for North Vietnam . . . . . . . 6-17
6-6. Target-Associated Radar Complexes . . . . . . . . . . . . . . . . 6-18
7-1. Target/Sensor Matrices . . . . . . . . . . . . . . . . . . . . . . 7-5
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
Commanders of military units require current intelligence about the enemy
forces with which they are, or may become, engaged. To satisfy this need, the
unit's intelligence element maintains a data base comprised of basic intelligence
information compiled prior to hostilities (frequently by higher headquarters),
and current intelligence derived from such sources as prisoner of war interro-
gation, defectors, surface reconnaissance units, and - most important of all -
aerial reconnaissance.
Airborne tactical reconnaissance systems in current usage are capable of
collecting large quantities of intelligence information. They employ optical
cameras, infrared detectors, radar, electronic intercept equipment, and visual
observation in the collection process. They may overfly the enemy's territory,
or they may fly along the periphery. The primary function of tactical aerial
reconnaissance is to obtain information about changes to the previously known
enemy order of battle and an assessment of our offensive actions. The urgency
with which this information must be made available to the commander and his
battle staff depends upon whether hostilities are possible, imminent, or under
way.
Under actual combat conditions, the commander requires current intelligence
in real time. Today, tactical reconnaissance systems can provide real time re-
sponse only through visual observation and radio transmission of the data. In-
formation collected by photographic devices and other sensors is not available
until the aircraft has returned to a base at which the film can be developed and
.the electronic records processed. The records must then be interpreted, and the
derived information collated with data from other sources, before the intelligence
picture is complete,
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
'S
SPECIAL HANDLING
A requirement exists to minimize the time between activation of the sensor
and delivery of the finished intelligence to the commander. An obvious solution
would be to provide the capability to process and interpret the sensor records
while the aircraft is airborne, and to relay the required information to the com-
mander by data link. Techniques for inflight processing of some, if not all, of
the sensory records are available today. The possibility of inflight interpre-
tation is more remote. This study is concerned primarily with an evaluation of
the usefulness of the various sensor records to the interpreter, without regard
to the techniques used to process them. The nature of tactical targets and the
ability of each sensor to record interpretable data about them are the main sub-
jects of this discussion.
1.2 AN OPTIMUM TACTICAL RECONNAISSANCE SYSTEM
To iterate, the primary function of tactical aerial reconnaissance is to ob-
tain information about changes to a previously compiled data base or order of
battle. This function can be satisfied if the collected sensor records enable
the interpreter to detect, locate, identify, and describe elements of the enemy's
forces quickly and accurately. The information content of such records thus can
be much less than would be required for a detailed technical analysis of military
equipment, but must be greater than would be required to compile a map or chart
of an area.
The tactical commander is essentially concerned with factual answers to
questions such as "How many fighters are operating from X airfield?" and "Has
the enemy moved a certain tank battalion across the river?" A theoretically
ideal reconnaissance sortie would answer these questions with "36" and "No".
An actual sortie will return to base with several hundreds of feet of film,
several magnetic tapes, pilot traces and observer notes, and perhaps other mate-
rials which must be subjected to time-consuming processing and interpretation
before the "36" and "No" can be ascertained. The sortie may also have encoun-
tered targets not listed on the flight plan, but obviously of military impor-
tance; intelligence about these targets must also be produced.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
NMOV N04
SPECIAL HANDLING
An optimum tactical reconnaissance system should minimize the quantity of
sensor records that must be interpreted, and thus achieve a corresponding reduc-
tion in the time required to answer the commander's questions. This optimization
involves careful planning that considers the intelligence required, the targets
to be covered, the routes and altitudes to be flown, the sensors to be used, and
the optimum methods of operating the sensors over the targets.
In order to define an optimum tactical reconnaissance system, it is neces-
sary first to list the targets the system's sensors will be required to recon-
noiter. The list should include those types of weapons, military equipment, in-
stallations, support facilities, and terrain features whose presence in an area
would be of concern to a tactical commander.
Each type of target has certain characteristics that differentiate it from
others. The target system must include a description of these characteristics
in order that the ability of various sensors to collect definitive information
can be evaluated.
With the possible exception of visual observation, none of the sensors used
in tactical aerial reconnaissance is completely selective. Each will acquire
and record data on any target whose emissions or reflections fall within the sen-
sitivity range of the sensor. The target list will assist in establishing sen-
sor sensitivity parameters that will result in collecting a minimum of redundant
information.
A basic target list has been developed (Table 1-1) and provided to the par-
ticipating contractors. Each contributor was requested to describe the parame-
ters of each target that permit its recognition or identification by the sensor
for which he is responsible, and to prepare a discussion of the optimum conditions
under which that sensor should be employed on a tactical reconnaissance mission.
The results of this request are contained in Sections 3 through 6 of this report.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
Table 1-1. Basic Target List
AIRFIELDS AND AIR ORDER OF BATTLE (AOB)
1. Types
A. 2000 ft and under
B. 2000 to 5000 ft
C. 5000 to 10,000 ft
D. 10,000 ft and over
2. Capabilities
A. Runways and Taxiways
(1) Surface
(2) Number
(3) Dimensions
(4) Orientation
B. Facilities
(1) Hangars
(2) Repair shops, stores
(3) Lighting
(4) Dispersal areas
(5) Open storage
(6) Underground storage
3. Order of Battle
A. Number of aircraft
B. Types of aircraft
C. Names of aircraft
4. Defenses
A. Anti-aircraft artillery (AAA)
B. Surface-to-air missiles (SAM)
C. Other (trenches, searchlights)
5. Electronics
A. Ground control approach (GCA)
B. Radar (other than GCA)
C. Radio
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
Table 1-1 (contd)
6. Support
A. Rail
B. Road
II GROUND FORCES AND GROUND ORDER OF BATTLE (GOB)
1. Troop Concentrations
A. Type of characteristics
B. Size
2. Vehicles including mobile weapons
A. Type
(1) Transport vehicles
(2) Tanks, armored scout cars, etc.
(3) Self-propelled guns
(4) Rocket launchers
(5) Armored personnel carriers
(6) Other
B. Size
C. Number
3. Fixed weapons sites, defensive positions
A. Type
(1) Field artillery
(2) Fixed missile sites
(3) Strong points, earthworks, trenches
(4) Barbed wire, hedgehogs, tank traps, etc
B. Extent
4. Command posts, headquarters, barracks, hospitals, etc.
5. Support facilities (supply, ammunition or petroleum-oil-
lubrication dumps, etc.)
III NAVAL INSTALLATIONS AND NAVAL ORDER OF BATTLE (NOB)
1. Harbors
A. Capabilities
(1) Size and depth
(2) Shipbuilding and repair
(3) Berthing facilities
(4) Piers (number and kind)
(5) Supplies and equipment
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
ioftw~ w
SPECIAL HANDLING
Table 1-1 (contd)
(6) Storage (underground and open)
(7) Sub pens
(8) Barracks
B. Order of Battle
(1)
(2)
(3)
Number of ships
Types of ships
Names of ships
C. Defenses
(1) Mines
(2) Submarine nets
(3) Guns
(4) Radar
2. Ships at sea
A. Carriers
B. Cruisers
C. Destroyers, destroyer escorts
D. Elint pickets, patrol-torpedo boats
E. Submarines
F. Other
IV TERRAIN
1. General land forms
A. Ridges, hills, cliffs
B. Valleys
C. Streams (depth, flow, banks, fords)
2. Beaches
A. Type (rocky, sandy)
B. Gradient
C. Hydrographic information
D. Routes of egress and ingress
E. Defenses
V COMMUNICATIONS
1. Radio
2. Land lines
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
Table 1-1 (contd)
VI TRANSPORTATION ROUTES (SURFACE)
1. Ground
A. Rail lines
B. Roads and major trails
C. Bridges, (rail and road)
D. Tunnels (rail and road)
E. Marshalling yards, terminals
F. Motor pools (with equipment)
2. Inland waterways
A. Ports and landing areas
B. Locks (lift in feet)
C. Basins
D. Trans-shipment points
E. Bridges
VII SUPPORT FACILITIES
1. Supply dumps
A. Petroleum-oil-lubricant (POL)
B. Ammunition
C. Other
2. Gun Parks
A. Type and number of weapons
3. Motor pools
A. Type equipment
4. Staging areas
A. Size
B. Ground force distribution
C. Equipment
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
1.4 TARGET/SENSOR MATRIX
The final section, Section 7, is a matrix that relates sensor capabilities
to various types of targets and to various operating conditions that affect these
capabilities. An arbitrary numerical scale is used to establish a relative rating
for each sensor used alone and for various combinations of sensors.
The cycle starts with the determination that additional intelligence is re-
quired about some aspect of the enemy's forces or capabilities. Frequently, a
single target or target area achieves an importance that establishes the need
for a sorties. Other targets enroute to or from the prime target are selected
at this time.
The flight plan is developed, with consideration being given to such factors
as anti-aircraft protection of the target area(s), the extent of the area(s) to
be covered (as related to the coverage capabilities of the sensors to be used),
aircraft operating characteristics, and penetration and evasion tactics to be
employed. A major portion of this step is determining which sensors will be used,
and how and when they will be used. This determination is based on the ability
of each sensor to acquire the required data under the planned flight conditions.
It is affected by weather conditions, time of day, nature of the targets to be
covered, and other operational and technical considerations.
The next step in the cycle is the accomplishment of the sortie. The crew
is expected to adhere as closely as possible to the flight plan; deviations are
permitted to assure the safety of the aircraft and, in rare circumstances, to
obtain coverage of targets of opportunity.
At some time after the sensor records its data, the record must be processed.
As stated before, techniques are available that permit some, if not all, of the
records to be processed while in flight. If these techniques are not used, the
aircraft must return to its base, where the records can be converted to human-
readable form.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
The processed records are delivered to the data reduction team who extract
the required information, collate it with corollary information from other sources,
and present the finished intelligence to the commander. The requirement to pro-
vide the commander with near real time information places constraints on this
step. The interpreter must be completely aware of the essential elements of in-
formation required in the circumstances at hand. He must limit his interpreta-
tions to extracting only immediately useful data.
It should be noted that there is a limit to the amount of information con-
tained in a set of reconnaissance records that is useful in a given situation.
This limit is often reached before the limit of interpretability is reached. As
soon as all useful information is extracted, any additional information provided
by other sensors, additional coverage, increased resolution, or more detailed
interpretation, is not significant, and time should be wasted in processing or
interpreting it.
The finished intelligence resulting from the sortie is incorporated in the
data base, and the cycle is complete. Any further exploitation of the reconnais-
sance data to extract more detailed information is outside the realm of tactical
reconnaissance, regardless of its importance to other aspects of a military oper-
ation.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
2. RECONNAISSANCE SENSORS AND THEIR CAPABILITIES
Visual reconnaissance is simple, direct, and capable of real-time response
in the form of voice transmission of observations. The use of visual observa-
tion is limited by the speed and altitude of the aircraft, concealment of the
target by clouds, vegetation, camouflage, and by other factors that affect the
observer's ability to detect and identify objects on the ground.
Visual observation can be enhanced by the use of devices that assist the
observer in detecting targets; moving-target-indicating-radar is an example.
Recording devices can be used to provide a permanent record of the observ-
er's report; these may be on the aircraft, at the home base, or both. Radio
transmission of oral reports can be speeded up through the use of an airborne
recorder and a high-speed transmission device.
Visual observation is usually employed against specific targets to obtain
specific information. Typical examples are the use of visual observation to ad-
just artillery fire, to locate a convoy en route to the combat area, or to search
for troop concentrations in an area.
Aerial photographs that meet certain operational and technical specifica-
tions can be the most valuable source of tactical intelligence. It is occasion-
ally difficult, and sometimes impossible, to meet these specifications. When
this is the case, other sensors must be used to acquire the data, or to acquire
data that will be useful in interpreting less-than-optimum photography. Addi-
tionally, the time required to return the film to the photo lab, to process it,
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
N401; %60
SPECIAL HANDLING
and to interpret it reduces the effectiveness of photography to provide intelli-
gence under rigid real-time conditions. However, technology advances in the
future could improve the transmission of near real-time photographic information.
The processing and interpretation time can be minimized if the character-
istics of the cameras to be operated over the target are carefully matched to
the sortie's requirements. Duplicate coverage of a target by more than one cam-
era may be desirable under some circumstances, but the need should be weighed
against the added workload in the photo lab and the additional imagery that must
be interpreted. Selection of the cameras and their mode of operation should be
governed by the types of target, the aircraft altitude, weather, and related
factors.
The imagery obtained on a photographic sortie will be used for one of two
purposes: to recognize a target, or to identify a target. "Recognition" implies
the ability to detect the presence of a target whose characteristics are known,
and to determine its geographic location. "Identification" implies the ability
to determine to some degree of detail the characteristics and military signifi-
cance of a target about which this information is not available. As an example
of the first purpose, it may be sufficient to establish that a tank battalion is
operating in a given sector; other intelligence is available as to the battalion's
strength and capabilities. As an example of the second purpose, it may be nec-
essary to determine whether a group of vehicles is comprised of tanks or of per-
sonnel carriers, and, if they are tanks, to establish their type or model. It
is obvious that the latter case requires better resolution and detail in the
sensor record than does the former. The ability of a photographic system (cam-
era, lens, filter, film, exposure, and processing) to record fine detail as it
applies to the utility of the system to provide interpretable intelligence in-
formation about specified types of targets is discussed elsewhere in this study.
To help assure survivability, tactical reconnaissance sorties will usually
be flown at altitudes less than 1000 feet or greater than 30,000 feet. It is
probable that a single sortie will include legs flown at high altitude and others
at low altitude. Two different sets of cameras will be required to meet the
intelligence requirements at these different altitudes. Cameras designed for
low altitude work are generally equipped with lenses of short focal length
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
(6 inches or less); they will produce vertical or oblique frame photos or strip
or panoramic photos; and they will be capable of producing high resolution
imagery at high velocity/ height ratios. Cameras intended for high altitude
work will use lenses of long focal length to obtain medium to large scale ver-
tical or panoramic photos of extremely high resolution.
Records produced by other sensors are often of value during the interpre-
tation of the photographs. For example, targets not readily visible on the
photo may be "pointed" by radar or infrared records; doppler radar can indicate
that a target is moving, thus modifying positional information derived from the
photo. Conversely, photography is almost essential in the interpretation of in-
frared and radar imagery. When lighting conditions preclude the use of cameras
concurrently with other sensors, photography obtained on previous sorties may be
used.
High-resolution side-looking radar uses a much longer wavelength than does
optical photography. For this reason, radar images can never equal optical
images in resolution. However, recent developments in such components and tech-
nology as synthetic array antennas, aperture focusing, and coherency produce
imagery that can be extremely useful in a tactical situation. Radar provides
its own "illumination" and can thus be used when optical cameras cannot; radar
energy can penetrate most atmospheric obscuration, foliage, and some other nat-
ural or man-made conditions or materials. As noted earlier, doppler radar can
be used to detect targets in motion. A disadvantage to radar is, of course, its
"active" nature which permits the aircraft to be detected and tracked.
Radar returns may be recorded in the air for delivery to the processing
facility upon return to base; they may be transmitted by a data link to a ground
processing station, or they may be converted in the air to an image that can be
displayed to the aircrew for various purposes. Radar thus has a real-time cap-
ability to provide intelligence information, either to the crew or to the command
post. The interpretation of this information will be enhanced if photographs of
the area being covered are available.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
%Nw No
SPECIAL HANDLING
The radar may be operated to provide "cueing" signals to an airborne ob-
server, or to provide an input to a device that will create, on photographic
film being exposed simultaneously, a record of the location of radar-detected
targets. Moving target indicator (doppler) signals can be used to generate
azimuth and range position data that will cause an area to be covered by high-
resolution or by other sensors aboard the aircraft.
Radar is primarily useful in the recognition phase of tactical reconnais-
sance, rather than in the description phase. In general, radar lacks the ability
to produce images that depict the true size and shape of the target, or that
depict texture and tone. Other deficiencies include the absence of returns from
a strip immediately under the aircraft, and obscuration of some elements of a
target by radar shadows.
Infrared detection equipment can be used to produce low-resolution photo-
graphic images, or electronic signals, that permit the detection and recognition
of thermal differences. Infrared sensors detect emitted or reflected invisible
radiations, rather than reflected actinic light; they may thus be used when
lighting is inadequate for photography. Thick clouds will interfere seriously
with all infrared operations; haze and turbid atmosphere adversely affect detec-
tion of radiation in the 1 to 8 micron range, while in the 8 to 13 micron range
haze and ground fog have little or no adverse effect.
Infrared imagery has sufficient resolution to permit the determination of
the shapes and sizes of objects as large as aircraft wings and fuselages. Smaller
objects can be detected, but probably cannot be recognized by virtue of their
size or shape. The availability of corollary intelligence information is prob-
ably more essential in the interpretation of infrared imagery than in the inter-
pretation of any other sensor record.
As is the case with radar, infrared can be used to cue the aircrew by
calling their attention to thermal anomalies in the scene. The range and azimuth
to an emitter may be recorded on the photograph, thus serving as a pointer to the
photointerpreter. Many photographically invisible targets can be detected by
infrared; cooking fires under a tree canopy are but one example. Similarly,
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
Nwo~ %W
SPECIAL HANDLING
infrared provides such indications of activity as differentiating between vehi-
cles with engines in operation and those whose engines have been inoperative for
a period of time.
2.5 ELECTRONIC RECONNAISSANCE (ELINT)
Electronic reconnaissance (ELINT) is used to collect information on the
enemy's electronic order of battle. This information is useful to ground, naval,
and air forces because of the wide range of electronic emitters that can be de-
tected and located, and whose operating parameters disclose their purpose.
Airborne ELINT systems can intercept signals over very long ranges, and
weather conditions have a negligible effect on this interception. ELINT infor-
mation is usually recorded in flight and returned to a data reduction facility
on the ground for processing. However, the data can be transmitted to the ground
over relatively narrow-bandwidth data links. Some processed signal information
can be displayed in the cockpit for use by the pilot or observer as navigation
aids, as cues to the location of significant targets, or for the selection of
electronic countermeasures.
When correlated with data from other sensors, ELINT data is useful in help-
ing to detect and identify such targets as radar-controlled guns or missiles,
aircraft control centers, and other targets whose function can be deduced from
the parameters of their associated electronic emitters. Other sensors may pro-
duce data that will assist in refining the location of an emitter, thus facili-
tating its destruction or neutralization by friendly forces.
An excellent general discussion, entitled as above, appears in the November
1964 issue of "Photogrammetric Engineering" (Vol. XXX, No. 6, Pp. 1005 - 1010).
Table 2-1, taken from this article, summarizes the advantages and disadvantages
of remote sensors.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
Table 2-1. Remote Sensor Comparison
Camera
Infrared
Radar
Day/Night
5
10
10
Haze-Fog Penetration
3
6
10
Cloud Penetration
1
2
9
Temperature Discrimination
2
10
1
Sub-Surface Detection
4
6
3
Stereo Capability
10
2
3
Accurate Image Representation
9
6
5
Long-Range Capability
7
4
8
Resolution
9
7
5
Interpretability of Imagery
9
6
6
Availability of Equipment
10
4
4
Poor = 0 Good = 10
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
3. PHOTOGRAPHIC RECONNAISSANCE
3.1 GENERAL COMMENTS
Aerial photography is the most useful all-around tactical reconnaissance
sensor. One or more cameras will be carried in any reconnaissance aircraft that
operates in daylight, or that carries artificial illumination for night photog-
raphy. The ability of a particular camera (or more correctly, photographic sys-
tem) to collect usable information about a target depends on a number of varia-
bles that are discussed in subsequent paragraphs.
As stated earlier, it is probable that a reconnaissance sortie will include
both high-altitude and low-altitude portions. Photographic equipment capable of
producing usable information from both of these altitude ranges is necessary.
The main limiting factors at low altitudes are the ability of the camera to cy-
cle rapidly enough to provide overlapping photography, its ability to compensate
for image motion, and the area it can cover. These are functions of focal
length, aircraft speed, camera mechanics and film format dimensions. The major
limiting factor at high altitudes is scale; this also is a function of focal
length and altitude.
The ability of a photographic system to resolve fine detail is perhaps the
overriding consideration in determining whether a certain class of information
can be recorded and interpreted. This ability can be affected by any or all of
the components of the system. These components include the lens, filter, film,
camera, exposure conditions, lighting, processing techniques, and interpretation
techniques. The system's resolving power is also a function of the contrast be-
tween the detail to be recorded and its background.
The balance of this section of the report is devoted to a discussion of the
factors mentioned above, and to conclusions regarding the effectiveness of pho-
tographic systems as an intelligence collection medium under tactical conditions.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
,%NW Nor
SPECIAL HANDLING
The scale of a photograph is simply stated as the ratio between the focal
length of the lens and the altitude of the cameras above the terrain. Scales as
small as 1:300,000 are useful for some types of tactical reconnaissance; for ex-
ample, map-type photography of a large area can be obtained with a minimum num-
ber of exposures using a 1.5-inch lens at altitudes of 35,000 or 40,000 feet. A
limited amount of tactical intelligence can be extracted from photography at a
scale of 1:20,000 to 1:40,000 (24- and 12-inch lenses, respectively, at a 40,000
foot altitude). Large scale photography (1:5000 or larger) is required for de-
tailed interpretation.
Scale per se is no longer a major consideration in evaluating a photographic
system. The components of a modern photographic system have so advanced that
scales previously unusable are now completely satisfactory. There are, however,
limits on the minimum scale allowable for specific types of interpretation.
These result from mechanical and optical characteristics of the image and from
characteristics of the photographic emulsion.
The photographic image is made up of individual and clumped grains of me-
tallic silver of a certain size range. Compensation for small scale by magnifi-
cation is limited by this grain size. Similarly, the ability of the system to
image detail is limited; detail whose image would be smaller than the size of
the largest grains cannot be recorded discretely.
The contrast between small details and their background is generally less
than between larger details and their background; this factor is discussed fur-
ther in subsequent paragraphs.
Although not strictly a matter of scale, the areal coverage capability of a
system also depends on the focal length of the lens and the altitude - and on
the additional factor of negative dimensions. Areal coverage capability deter-
mines whether a given system can obtain the necessary coverage of a given target
at a given altitude.
This study is based on the fact that photography will be obtained at alti-
tudes between 200 and 1000 feet and between 30,000 and 40,000 feet? Cameras
will have focal lengths ranging between 1.5 to 24-inches. The various combina-
tions of focal length and altitude produce three general scale ranges. These are:
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
Small scale
(1:200,000
- 1:300,000)
Medium scale
(1:20,000
- 1:40,000)
Large scale
(1:500
- 1:2000)
3.3 PHOTOGRAPHIC RESOLUTION
The resolving power of a photographic system is indicative of its ability
to record fine detail. In a general sense, resolving power is the reciprocal of
the smallest dimension that can just be seen in a photograph; it is stated in
terms of the number of line pairs per millimeter that the system can image as
discernible lines.
The resolving power can be used to predict the ability of the system to pro-
duce a readable image of various objects on the ground. The formula for this
prediction is
GR = S/300L,
where GR is the ground distance resolved, S is the reciprocal of the photographic
scale, and L is the resolving power in lines per millimeter. The factor "300"
(actually 304.8) converts GR to feet. This formula must be used with caution
for the reasons described below.
3.3.1 Computation of L
The numerical value of L is usually determined by examining the image of a
standard Air Force three-bar resolution target photographed by the system being
calibrated. This target is illustrated by Fig. 3-1. The smallest three-bar
group that can be discerned as separate bars on the image determines the value
of L. However, this value refers only to the ability of the system to resolve
regularly repetitive detail at a specific object contrast (discussed shortly)
and aspect ratio. Further, the quoted value is actually only an indication of
the central tendency of the values derived during a series of replicate tests.
This is illustrated by Fig. 3-2, which is a plot of 163 values obtained from a
test of a specific emulsion under closely controlled replicate conditions. The
standard method of reporting L is to quote the arithmetic mean - in this case,
316 lines per millimeter. It can be seen from the figure that many values
greater or less than this are present.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
,%~ *4111111101"
Group -2 -1
Step lines/nun lines/mm
1
25.0
50
.0
2
28.1
56
.1
3
31.7
63
.5
4
35.6
71
.2
5
39.9
79
.9
6
44.5
89
.1
0
1
lines/mm
lines/mm
100
200
112
225
126
254
141
285
159
320
178
356
RESOLVING POWER TEST TARGET
SPECIAL HANDLING
USAF Resolution Chart
Fig. 3-1 - Three-bar resolution target.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
alpulatedlmean= 1
L/mm
i
,
I I
I
I
I
-3{r
I
I
I
I
+1
I
+ U +310-
I
I ~ I
I ,
I I
I
I
I
I
I
I
~
l
I
I I
I I I
I
I
I
I
I
I
Fig.3-2 - Frequency of occurrence vs resolving power for film type
4404 data at 2:1 object target contrast
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
*"001 Nft*F
SPECIAL HANDLING
A value for L obtained under controlled conditions will seldom be valid
under field conditions. Even minor variations in any of the parameters of the
photographic system will have an effect on this value. It is possible, however,
to establish a value for L that can be consistently achieved in the field under
standard conditions. It is essential that all the conditions in existence when
L is derived be known and stated, in order that they may be duplicated or, if
this is impossible, compensated for. For the purposes of this study, the values
of L used in various tables are attainable under actual field conditions, as de-
termined by examination of operational photography. It is convenient to refer
to such field-derived resolution values as "operational resolving power".
3.3.2 Object Contrast
Any value for L is theoretically valid for only one object contrast. Ob-
ject contrast is the ratio between the brightness of the object and the bright-
ness of its background. Note that the object may be an aircraft on a runway, or
a rifle on a tank; the contrast between the things that actually comprise the
target must be considered in any computation of ground resolving power of a sys-
tem. This factor is discussed in some detail in the following subparagraphs.
Contrast is affected by color or tonal differences, by the intensity of the
illumination, by the sun angle, by the size of the components of the object to
be imaged, and by scale and altitude. The Air Force bar target referred to
above is made at two contrasts - 1000:1 and 1.6:1. The resolving power of the
system varies for these two contrasts, and the quotation of L must be accompa-
nied by a statement of the contrast of the target used. See Fig. 3-3 and Table
3-1.
It may be assumed that the enemy will make every effort to reduce the visi-
bility of his equipment and forces by using protective coloring or camouflage.
Thus, most tactical targets can be expected to have relatively low contrast with
their backgrounds. Note that this implies that the components of a target will
often all be of the same color or tone, and that the color or tone of the target
will match its background. There are obvious exceptions; dark-colored vehicles
may operate against a background or of snow or concrete, or unpainted aircraft
may be parked on a Macadam hardstand.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
4
1
Target
Contras
1., 000:1
8: 1
2: 1
4.52 Absolute 1.0
Log E
Fig. 3-3 - Resolving power vs log exposure for
SO-102 film, D-19 development, 6 minutes at 68?F.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
Table 3-1. Resolving Power Values for Representative
Aerial Emulsions, L/mm
Target Luminance Ratio
0404 (SO-132)
840
550
280
S0-243
540
440
260
S0-206
380
270
160
S0-226
340
260
160
S0-190
240
180
120
SO-136
180
150
100
f400 (SO-130)
170
150
100
4401 (SO-102)
120
100
65
8401
110
90
50
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
NO;
SPECIAL HANDLING
,Object contrast is reduced when the intensity of illumination is reduced.
This reduction is nonlinear; dark objects are affected much more than are bright
objects, even though their contrast ratios are the same. Most objects of impor-
tance in tactical reconnaissance will be dark in color; the intensity of illumi-
nation is therefore an important consideration in assessing the effectiveness of
a photographic system. Intensity is a function of the time of day, time of year,
latitude, and atmospheric conditions. Illumination also affects the intensity
of shadows, which provide a valuable form of object contrast.
A decrease in the size of the detail to be resolved results in a decrease
in contrast between the detail and its background. According to Macdonald
(Photogrammetric Engineering, March 1958, p. 50), " . . . more resolution lines
per object are required to detect the image, the smaller the scale of the image.
A corollary to this statement is that high resolution systems require more res-
olution lines per object in order to detect the image at the limit of the system
than do low resolution systems".
Photometric data compiled by P. D. Carman and R. A. F. Carruthers (Journal
of the Optical Society of America, 41:305-310) indicate that targets typical of
those of concern in tactical reconnaissance (man-made complexes of cities and
towns) have a contrast range that rarely exceeds 10:1 (a comparatively low value)
from an altitude of 4000 feet. At "hyper-altitudes", a much lower contrast will
be obtained; a ratio of 2:1 or even lower should not be unexpected.
The meaning of values for GR obtained from the given formula must be under-
stood. If the formula produces a value for GR of 2 feet, this means that an ob-
ject with a minimum linear ground dimension of one foot should appear as a just
discernible blob on the film, if it is surrounded by a contrasting area with a
minimum dimension of at least one foot. Thus the values of GR determined in
this manner refer only to the detection step of the photointerpretation process.
The recognition of an object requires a resolution some five times finer than
the computed value of GR. Identification may be possible at this finer resolu-
tion if the interpreter is highly skilled and has additional information on the
target, but it is probable that still finer resolution will be required in many
tactical reconnaissance situations.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
Although any number of scale and resolution values will produce the same
computed GR, scale and resolution are not interchangeable at parity. If scale
and resolution are to be traded, the trade should be in favor of larger scale
and lower resolution to obtain the most information from the image. Stating
this principle differently, as the scale of the object decreases (i.e., as its
image becomes smaller), the number of lines required to detect it becomes
large;
3.4 TARGET CHARACTERISTICS
Each target has certain characteristics or sensor signature that differen-
tiate it from other targets. The term "target" in this sense refers to the
thing or place about which information is desired. It may be major installation,
a vehicle or weapon, a mine field, or a component of a vehicle necessary to the
identification of the vehicle. The level of interpretation that can be achieved
from a photograph depends on how many, or which, of the target's characteristics
must be recognizable and perhaps measurable, and on how well these characteris-
tics are imaged.
It is convenient to refer to these characteristics in terms of the three
categories of detail that must be recognizable to permit the positive identifi-
cation of the target. Table 3-2 describes general treatment of this categoriza-
tion. It groups under three headings - "Gross," "Medium," and "Fine" -
examples of the kinds of things or places that can be identified from imagery
at these levels of detail.
3.4.1 Gross Detail
The level of detail denoted as "gross" includes targets or target compo-
nents 10 feet or more in minimum dimension. This level will enable an interpre-
ter to recognize large targets such as airfields, port facilities, garrisons,
depots, etc. It will not always permit the functions of such installations to
be clearly identified. For example, an airfield could be located and identified
as an airfield but the type or function; i.e., military, heavy bomber, fighter,
or civilian, could not be established at the gross level of detail.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
%4001 VMW
SPECIAL HANDLING
Table 3-2. Targets Categorized by Detail Level
GROSS DETAIL - Targets in this group can be identified from imagery with ground
resolution of not better than 10 feet.
Airfields (paved runways)
Ports and harbors
Military installations
Industrial installations
General terrain information
Large vessels
Large buildings (hangars, etc.)
Large open storage areas
Tank farms
Railyards and facilities
Transportation network
Towns and villages
ICBM/MRBM sites
Large dams
MEDIUM DETAIL - Targets in this group can be identified at ground resolutions
of 2 to 10 feet.
Operational details on targets in
preceding group
Types of vehicles, railroad cars,
aircraft, smaller vessels
Types of materiel in open stores
Underground bunkers; revetments
Large radar antennas
Large weapon emplacements, guns
Sodded airfields, helicopter pads
Minor roads, trails
Passive defenses (trenches, wire, tank
obstacles, etc.)
Trafficability of sectors of transpor-
tation network
Field command posts, bivouacs, camps
Beach gradients, trafficability, exits
Vehicular activity
River ports
Agriculture, vegetation (general in-
formation)
Surface-to-air missiles
FINE DETAIL - Targets in this group can be identified at ground resolutions
better than 2 feet. This group includes components of larger targets; identi-
fication of these components permits a more detailed or exact determination of
the identity and military significance of the "parent" target.
Operational details on the preced-
ing groups of targets
Individual personnel, personnel
shelters, foxholes
Beasts of burden; porter trains
Detailed designation by type and
model of vehicles, weapons, air-
craft, vessels, etc.
Details on crops
SPECIAL HANDLING
Detection of military use of civilian
vehicles, river boats, etc.
Ambush and surveillance sites
Anti-helicopter landing stakes
Cooking fires, campfires
Trails, small streams, fords
Mine fields
Automatic weapon emplacements
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
3.4.2 Medium Detail
"Medium" detail includes targets or components from 2 to 10 feet in size.
It will permit identification of the function of an installation, or identifica-
tion of smaller objects. Buildings could be measured and identified as to func-
tion; vehicles and other targets of similar size could be identified by generic
name. The airfield located under the gross level of detail could, under the
medium level, be identified as to type and function, and the aircraft could gen-
erally be identified as to types and classes.
The "fine" level of detail includes targets or components 2 feet or less in
minimum dimension. With this level of detail all installations may be fully
described, with the status of occupation and operation defined in detail. Types
and models of aircraft, ships, vehicles, radar, etc., can be determined. Per-
sonal equipment and other very small detail may be identifiable.
3.5 EVALUATION OF PHOTOGRAPHY AS A RECONNAISSANCE SENSOR
The various cameras that are, or will be, available for tactical reconnais-
sance were analyzed in terms of their ground resolution, areal coverage, and
cycling rate. Table 3-3 is a compilation of these data on vertical cameras with
five different focal lengths and with various image dimensions. The data in
this table may be taken as typical of the performance of tactical cameras.
The values for ground resolution indicate the dimension of the smallest ob-
ject that can be identified (at least as "probable") from its image. The values
were established by computing GR for each of the L values, using the formula
previously given, and multiplying this result by 3 for large scale, 5 for medium
scale, and 1.0 for small scale. The values for S were taken as the approximate
midpoints of the ranges produced by the various combinations of focal length and
altitude. These values are 1000 for large scale, 30,000 for medium scale, and
250,000 for small scale.
The multiplying factors (3, 5, and 10) used in compiling Table 3-3, are
empirical approximations. The table indicates that detail as small as 2-inches
in its minimum dimension can be identified from large scale imagery produced by
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
Table 3-3 - General Camera Information for Flight Altitudes
of 1000 and 30,000 feet at Flight Speed of 1000 Knots
Focal
Length
Ground Resolution
In Feet
Film
Size
Swath Width
In Feet
Cycle at 1000 fps
for 55% FWD
Overlap
L/mm
1000'
30,000'
1000'
30,000'
1000,
30,000'
150
0.197
5.25
2"x2"
1,333
40,000
0.47
14.13
100
0.262
7.87
511x5"
3,325
116,666
1.16
35.32
1 1/2"
50
0.524
15.75
9"x9"
6,000
180,000
2.12
63.64
25
1.05
31.50
9"x18"
150
0.098
2.62
2"x2"
666
20,000
0.23
7.07
100
0.131
5.24
5"x5"
1,651
50,000
0.59
17.66
50
0.262
10.48
9"x9"
2,999
90,000
1.06
31.97
25
0.524
20.96
9"x18"
0.048
1.48
2"x2"
333
11,250
0.12
3.53
0.065
1.97
5"x5"
833
25,000
0.29
8.82
0.131
3.83
9"x9"
1,500
45,000
0.52
15.89
0.262
7.67
9"x18"
0.74
2"x2"
5,600
0.06
1.76
0.98
5"x5"
12,500
0.14
4.42
1.97
9"x9"
22,500
0.26
7.94
3.94
9"x18"
0.37
2"x2"
2,800
0.05
0.88
0.49
5"x5"
6,150
0.07
2.21
0.98
9"x9"
11,250
0.13
4.06
1.97
9"x18"
22,500
0.13
4.06
5,600 Computed but not considered practical
SPECIAL HANDLING 3-12
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
1
SPECIAL HANDLING
a 1.5-inch lens at 150 lines per millimeter. Since the formula, by definition,
gives the width of a resolved line pair (i.e., the image of a line that contrasts
against a surrounding background of equal or greater width), the tabulated val-
ues may be halved with reasonable assurance that objects with the smaller dimen-
sion can be identified, at least at the "possible" level.
The GR values in Table 3-3 are based on the assumption that the photos are
made under bright sunlight and that the targets have an object contrast in the
10:1 range. The increase in the multiplying factor is intended to compensate
only for the effects of reduced object contrast caused by reduced scale. Iden-
tification of targets with less than a 10:1 inherent object contrast will require
better resolution than that stated in the table. Similarly, reduction in object
contrast caused by reduction in the illumination must also be compensated for.
These two factors are additive.
The implication that can be derived from Table 3-3 is that almost any tar-
get of concern in tactical reconnaissance can be imaged with adequate scale and
resolution by one or more of the cameras aboard the aircraft at either high or
low altitude if the 150 lines per millimeter resolution can be achieved.
Macdonald, Duncan E., Resolution as a Measure of Interpretability, Photogrammet-
ric Engineering, March 1958.
Itek Report 1011-1, Photographic Considerations for Aerospace Reconnaissance,
April 1964.
Itek Technical Proposal 3535, Ground Resolutions Required for Intelligence
Information, October 1963.
Rome Air Development Center Technical Report TR-60-101, on The Compilation of a
Manual for Screening Small Scale Photography, May 1961.
Rome Air Development Center Technical Report TR-60-152, Small Scale Aerial
Photography, September 1960.
Yost, E. F., Resolution and Sinewave Responses as Measures of Photo-Optical
Quality, Photogrammetric Engineering, June 1960.
Perrin, Fred H., Methods of Appraising Photographic Systems, Journal of the
Society of Motion Picture and Television Engineers, March and
April 1960.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
NoFf
SPECIAL HANDLING
Tarkington, Raife G., Photography Rediscovered, Signal, May 1959.
Itek Report, Research Plan in Reconnaissance, February 1964.
Katz, Amrom, H., Selected Readings in Reconnaissance, Defense Documentation
Center, AD-416410 (Published by the Rand Corporation, August 1963).
USAF, Concepts for Tactical Air Reconnaissance in Joint Operations (Tentative),
USAF Tactical Air Reconnaissance Center (For Official Use Only).
Photo Interpretation and the Cuban Crisis, Photogrammetric Engineering,
January 1963.
Manual of Photographic Interpretation, American Society of Photogrammetry, 1960.
James, T. H. & Higgins, George E., Fundamentals of Photographic Theory, 1960.
Mees, C.E.K., The Theory of the Photographic Process, 1942.
Neblette, C. B., Photography Principles and Practices, 1942.
Katz, Amrom H., Observations Satellites, Problems and Prospects, Rand Corpora-
tion, May 1959.
Crouch, L. W., High Performance Mapping Equipment and Materials, Photogrammetric
Engineering, March 1961.
Department of Defense, Various Field Manuals and Technical Manuals.
North American Aviation Report 64H-732, RA-5C Image Forming Subsystem
(Confidential).
HRB Singer, Inc., Spectral Variations of Terrains and Targets (U), March 1965,
Secret.
Fedler, Allen M., Interpreting Natural Terrain from Radar Displays, March
1960, (U).
Aerospace Corporation, (Contract No. AF 04(695)-269), Infrared Today and
Tomorrow, March 1964, (U).
Northrop Aircraft, Inc., First Interim Technical Report Mapping from Airborne
Radar Scope Presentations, Contract No. DA-44-009 ENG3362 Project
No. 8-35-11-104, June 1957 - September 1957, (U).
Biberman, Lucien, Detection of Infrared Targets Against Infrared Backgrounds,
August 1960.
Leonardo, Earl S., Capabilities and Limitations of Remote Sensors. Photo-
grammetric Engineering, November 1964.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
4. RADAR RECONNAISSANCE
4.1 GENERAL
The usefulness of radar in the detection and recognition of different tar-
gets depends upon several particulars. The basic outputs of a radar system are
imagery and moving target indications (MTI). The factors which influence the
system's performance are summarized below.
4.2 IMAGERY FACTORS
Targets can be identified from radar imagery because of variations in radar
cross-section or radar reflection coefficient. Either high or low radar return
is discernible. Targets can be recognized by the size and shape of their images.
Radar imagery differs from photographic imagery in several particulars which now
will be discussed.
Radar provides its own illumination; therefore the target is always illumi-
nated from the same direction as it is viewed. Radar shadows thus fall in a pre-
determined direction regardless of time, weather, or day-night condition. The
amount of shadowing can be controlled by setting the incidence angle to the
earth. This shadowing is helpful in recognizing terrain features and contours,
but it can hide targets of interest. Past experience with high resolution radar
imagery has shown that acceptable performance over average terrain can be ob-
tained down to incidence angles of three degrees.
The radar reflectivity of an object usually bears little correspondence to
its optical reflectivity. The radar cross-section of a resolved ground patch
can vary from a few hundredths of a square foot to one thousand square feet for
a vehicle. Man-made objects, especially metallic ones, tend to have many spec-
ular reflection points. This, in turn, produces a large average cross-section;
SPECIAL HANDLING 4-1
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
VW
SPECIAL HANDLING
therefore large radar returns are important cues to the existence of military
vehicles, weapons, supplies and structures. On the other hand, it is difficult
to identify objects by examining radar imagery alone. However, the location of
a large radar signal return can be a cue for the reconnaissance analyst to in-
spect corresponding portions of the photo and infrared records.
The resolution and contrast required to recognize size and shape on a radar
image differ from those required by an optical photographic system. In general,
finer resolution is required for synthetic-array radar than for photography.
This is due both to the coherence of the radar energy, and to the fact that the
principal return from many objects is actually a composite of reflections from
specular points. The fact that a synthetic-array radar is coherent means that
at any given aspect angle the diffraction pattern from a reflector can be at a
peak or a null depending upon the incidental reinforcement or cancellation of
the reflected electromagnetic waves. Unless some averaging is applied to the
aspect angles, coherence can lead to "spotty" returns. Returns from specular
points may not correspond to the outline of the target, making it more difficult
to recognize size and shape. These factors mean that finer resolution is some-
times required for radar than for photography to achieve the same level of target
recognition.
For synthetic-array radar, resolution is usually defined as the 4db distance
width of the point reflector response function after signal correlation. When
two point reflectors, such as corner reflectors, are separated by this distance,
then 50 percent of the time the correlated images will have at least 20 percent
contrast (peak to maximum ratio). Resolution is useful for battlefield surveil-
lance and target recognition down to values of 1 or 2 feet. However, the present
radar state-of-the-art does not allow such fine resolution. Shown in Fig. 4-1
are probabilities based on radar sensor resolution in feet of recognizing various
military targets. It can be seen that several high-value targets require reso-
lutions of the order of 1 to 5 feet to achieve a high probability of detection.
Fine-resolution synthetic-aperture radar has the potential to achieve at least
the upper region of this capability.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
SPECIAL HANDLING
eo L-coai-4
a)
ro
'may a)
N C: ?.4
14 O u)
a1 ?.4 [a
,'-i H 44 O
F1-1 - LI n
. 4a C 4-1 O
4-I w ?.4
O ui ,-4
k1 u -~ a)
di N PQ U
- 40 Gcs
Radar systems are normally employed for specific functions and have recog-
nizable characteristics which distinguish one type of emitter from another. The
radar systems to be found in a typical battlefield situation consist of a com-
bination of strategic and tactical emitters which may be classified according to
function as shown in Table 6-1. The abbreviations given for each class in the
table are quite standard and will be used in the remainder of this report.
Many radar systems are capable of performing combinations of the functions
shown in the table. For example, an early-warning radar may also be used as a
surveillance radar. Also, when operating with a radar having a height-finder
capability, the combination can be utilized as a ground-control intercept (GCI)
radar.
6.2 TARGET RECOGNITION CHARACTERISTICS
Because battlefield radars and communications equipment are designed for
specific functions, there is usually a significant difference in their signal
characteristics which enables them to be easily identified by ELINT processing
equipment. Early-warning radars, for example, generally use low frequencies,
high powers, and long pulse widths to achieve maximum range against small air-
craft targets. Fire-control radars, on the other hand, generally use higher
frequencies, medium power, and short pulses to accomplish precision tracking of
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
Table 6-1. Radar Classification by Function
Designation Radar Function
AAFC Anti-Aircraft Fire Control
ACQ Acquisition
AI Airborne Interceptor
BS Battlefield Surveillance
CS Coastal Surveillance
DT Data Transmission
EW Early Warning
FC Fire Control
GCA Ground Control Approach
GCI Ground Control Intercept
HF Height Finder
IFF Identification Friend or Foe
MC Missile Control
NAV Navigation
RS Radio Sonde
ST Shell Tracking
SURV Surveillance
TT Target Tracking
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
aircraft targets already acquired by acquisition radars. Some radar equipments
use simple pulse modulation while others use more exotic modulation methods.
Since each functional type has been designed to accomplish its particular task,
its design parameters can be related to function when the intercepted signal is
analyzed.
Emitter signal characteristics which can be utilized to identify the source
of an emission pertain to the frequency, modulation characteristics, and antenna
patterns of the radiator. A tabulation of the parameters which can be used is
contained in the following list. The direction-of-arrival and time-of-arrival
parameters are not characteristics which normally could be used to identify an
emitter, but are included to make the list complete.
Emitter Signal Parameters
Radio Frequency (RF)
Pulse Repetition Interval (PRI)
Pulse Repetition Rate
Pulse Width
Pulse Amplitude (Signal strength)
Modulation Characteristics (Non-Pulse)
Duty Factor
Antenna Scan Rate and Pattern
Antenna Beamwidth
Polarization
Side Lobe Level
Within Pulse Modulation
Direction-of-Arrival
Time-of-Arrival
ELINT systems used for strategic reconnaissance attempt to evaluate many of
these signal characteristics, especially when new or different emissions are in-
tercepted, so that a complete evaluation of the enemy's tactical capabilities
can be maintained. However, for purposes of tactical reconnaissance, it is nec-
essary to measure those parameters which are required to insure a high probabil-
ity of identifying the target. Technical Intelligence is not a tactical recon-
naissance function.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
A study of the emitter signal parameters given above has shown that the
measurements of frequency and pulse repetition interval (or its reciprocal,
pulse repetition rate) are usually sufficient to provide a rapid and positive
identification of most radar types. Pulse width and emitter antenna scan rate
can be useful in resolving the few remaining ambiguous radar identifications.
To identify a communications type emitter positively, it is necessary to measure
the basic modulation characteristic of the emitter. Such modulation character-
istics as single sideband suppressed carrier, frequency modulation (FM), pulse
code modulation-FM, and others, can be recognized by the ELINT processing logic.
The location of a radiation emitter by an ELINT system involves the solu-
tion of a triangulation problem, using the relative bearing angles of the emitter
from the reconnaissance aircraft, and a base line established by the movement of
the aircraft. This technique is a requirement because there is no known method
of determining the range to a source of radiation when using a single passive
receiving system.
The accuracy of triangulation is primarily a function of the accuracy with
which the angles of arrival of an intercepted signal can be determined, and the
length of the base line between the angles measured. The longer the base line
(within limits), the more accurate the "fix" which can be made, since the acute-
ness of the arrival angles contributes to the uncertainty of the location
measurement.
Airborne ELINT systems generate the base line of the mensuration triangle
by "flying by" the emitter source for as long a period of time as is feasible.
Obtaining many measurements of emitter-bearing angles during the fly-by makes
the triangulation more accurate because of the more favorable angular relation-
ship. It also provides a large statistical improvement in the accuracy of
emitter location. The statistical improvement is a function of the square root
of the number of bearing measurements made, and is quite significant when a
large number of "cuts" can be taken. In fact, because of the statistical im-
provement which can be attained, it is not necessary to use a high resolution
approach in the design of the ELINT angle measuring components.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
%ftw 1%W
SPECIAL HANDLING
There is also a solution to the location problem which uses the altitude of
the reconnaissance aircraft above the earth's surface, in conjunction with meas-
urements of the vertical depression angle from the aircraft, to provide the tri-
angulation. However, this system is only accurate at high altitudes of flight
because, as the altitude is decreased, the vertical angles become grazing angles
which cannot be measured accurately.
In currently programmed ELINT systems using the fly-by technique, emitter
locations can be determined within an accuracy of approximately ?3 percent of
the range. The range is the range of the emitter "abeam" the reconnaissance
aircraft (perpendicular to the flight path at the point of minimum range).
Accuracies of approximately ?5 percent of range can be attained by using only a
few fixes, without flying by the target.
The emitter location systems using the radio altitude and vertical depres-
sion angles can achieve location accuracies of approximately ?3 percent of range
at ranges where the vertical angles remain larger than approximately 10 degrees.
In order to define the problems involved in identifying and locating radi-
ating targets by means of ELINT systems, and to obtain preliminary solutions to
them, it has been found helpful to examine in detail existing and postulated
radar signal environments. Radar Order of Battle (ROB) and emitter signal
characteristics are available for most of the world, and from these such signal
environments can be derived. By means of these environmental models the actual
frequency distribution, signal densities, pulse repetition interval limits and
other factors can be ascertained.
Two environmental models have been constructed for this study, and it is
from these that the final conclusions are drawn. The first environment postu-
lates a carrier task force operation in the Baltic Sea near the Soviet mainland
during the 1967-70 period of time. The advantage in using the Soviet Radar Order
of Battle is that the equipment characteristics will be identical to what will
be found in any of the Sino-Soviet nations or their satellites, since classes of
Russian equipment are being distributed throughout these areas. By using the
Soviet mainland, where both strategic and tactical emitters will exist, a very
dense signal environment will be present.
SPECIAL HANDLING 6-8
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
vftw *M01
SPECIAL HANDLING
The second environmental model constructed for this evaluation is also for
the 1967-70 time period and postulates a carrier task force operation near North
Vietnam. Although this is representative of a sparse signal environment, the
classes of equipments are similar to those that exist in the denser environment.
6.4.1 Soviet Mainland in Baltic Sea Area
The area chosen for this analysis, although possibly not realistic from the
standpoint of an actual carrier task force operation, is representative of tac-
tical reconnaissance in an extremely dense emitter environment. Therefore, any
analyses made within the framework of this environment can be very useful in
defining the types, probable disposition, and maximum number of enemy emitters
in a very dense battlefield situation. Such information is of vital concern to
the designer of ELINT systems because it enables him to estimate the maximum
signal pulse density, the degree of pulse interleaving likely to occur, the
type of signal sorting to be employed, and other important factors.
The area under consideration is approximately 8000 square miles and con-
tains, in addition to the strategic emitters, the tactical emitters associated
with a Soviet Combined Arms Army (CAA).
The total electromagnetic environment within this area between 30 megacycles
and 30 gigacycles originates from four separate types of sources:
a.
Strategic
Emitters
b.
Tactical
Emitters
c.
Airborne
and Shipboard Emitters
d.
Communications Equipment
Table 6-2 contains a list of the Soviet strategic emitters found within this
area. This environment was obtained from the latest available Radar Order of
Battle (ROB). Since the time period of interest is 1967-70, the strategic en-
vironment has been increased by 5 percent to account for estimated growth. In-
cluded in this table are the functions and signal characteristics of each emit-
ter, including the total number of each type to be found in the area of interest.
A similar breakdown of the Soviet tactical emitters to be found within this area
is given in Table 6-3. The total number of tactical emitters is based on den-
sities previously established for a Soviet CAA. The densities used in this study
are as follows.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
(N r-I(N - - I ~0
14
al
0
IL4
cu LCJ CV -4 (=> GV cV cV cV
a) O
w C11 rI r
O O m cy" O 00 L- O
c' c+ cal r-1 r-1 O O r-i LO
cV cV L(~ 00 I L J L~ d1
c.1 c~r-100000
M Cq r-4 M - N (N 00 r4
(=> Lc) 0 0 0 -I O O r-1
O cV 0 0 0 LO LCD
Lfj LO
( 1 r-I -1
LO LO r-1 (N
~ r-I CC r-1
I I I I
r-1 O
0 0 0(=0mMm r-4 LO ON
00 00 00 LO X Q) Lfl t LCD L- O 00
co co CY) M CV Lf) 0 r-4 r-1 L ) r4
w r-1 cV r-1 (N r-4
Pi I I I I I I I I I I I I
P-+ O O 0O dl 92 LOt- oo oti
CO L- Lam- LO L- C- CSC -I c+^J LO eH
co c M c~ c ~ c a -4 ~ C? b- CO
CO 1-1
u m ul~ L?M C?-MrQ LO -4iNQmC.0mw
r-4
r-4 `O co co coo cm 0W LO
I I I I I I I I I I I I
P C11 c(V ( c0~1C'1 m n4 I
0 c> C) (D 0 a) (D 0
000 dNmCCO
000
Co Q LO O O cV C0 0 m da C N
0 r4 r-4 M c+0 C-1 co cV CO O
o CO 0 00 LO 00 00 O LCD L- O
0 00 C? CO ` 00 00 CO LO -4 L-
CN CO (N
I I I I I I I I I I I
00cV00000 0 0CLCJ
cn cq 00 O t- 00 00 0 00 U 'D o
CO r-1 L~
In 00 00 CO Co
cal m cV (N (
G
0
C0 u ?U A H H w x 8 ' W
a) -14 4 0 114
41
.1-I 0 C I w u
?r1 F-1 P~ ~, V] R
CA
W Lid
r-4 r.4 N N
Pa PA Pq U A
44 Pq U 4
I I
n w I -~'J 4J 41 4-1
to 00 4- N u ,-1 N ai aa) x aa) N
0 0z wHaar~ c~ w a)
P; q Cep k cad 0 wr1 ~r1 -H 44 -14 U 0 H
Cd rd ?rl ?r1 -4 0 a) G r- 0 1 a +-I
w 44 44 w wxa ~4 Pa MEn V)
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
mil r-4
-
0
H
x-4 ~ OOGV c%1 N
C N C' J
9 1- m LC Oda i c7
T O r-I r-I r-I r-1 '-I -
G~1r~4X d+L~ L~00
O O 0 0 0 0
0 0 o 0 o Lr~ LO M o
a~~eooo~caaor-oo
w
a o 0 o Lc~ o 0 0 o 0 0
Nwmcocu~r+~~
au
-4
qj
H
>1
u
Q
t!
LOCH CH t- COV
to
N
O
V.0 (LO O
}4
Co
m r-I L-
rX4
N
00 cq
G
O
O'
1J
~?.
u
W
x
H
O CU,
v
U
0)
b
Pa
.u 0
W
O
'H-+
W
N
C/ H H
v] -
-4
cq CO LO LO 0
00 00 00
CM CD C9 Cp
Uc In Li LOCH
C9 Co CD CD
cq
P4 W W
rr' H H H
di Lc~
44 4
?H 4-J 4
933
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
w
SPECIAL HANDLING
cq uJL`~LCJ-md1 I
L- - 00 It mI N G~ J C~7 m
m C- r4 MLOM LCD CV
W
LCD O c0 LCD LCD LCD O
cd CV LCD cV CV CO CO
CD LO
~4 "di
m r-I
LCD LC
Lam- O 00 LOO CV CO r4 0 O
LO
O rl 0 CV r-1 r-1 O CO O dI CC
I I I I I I I I I I
CIV L~ --1 00 CO C J I O O
? ?
000 r-10 0? 0 O CV CV
CO r10 00 00000 MO0
d+LnL- OO coo cV oc000
Q C~~I~ ~00 cqw~ccq cC'1 ce)
I
?a I I I LfO 0 I I O O O I I I O O I I O C7 I I O O
h 0
r-1 C' LCD cO O O O O LCD 00 W r4 LO O
c t- 00 Co Lf~ L- CV LCD r1 CV d+ CV O
r-1 1-1 r-I CV CV -4 cV CV N
u cDhLO Cn00
d1 LO CV HOm
P CCc0000 0Cm
m 'JO 'i~ O 00
W d+ da Cq m
q
0
u
a oW W H 6
U ~bD
4.1 0 w H
IJ 0 c cA H
co
o
r%4 c w a
OCV00000 LO 00
L- LO c to r1 00
c O C'
I I I I I I I
0000 m CO r-1
LO CV LCD O LCJ CV 00
N
LCD CV CO d+ r-4
CO O CV
wr!~ c C/~
H m H Pa W-1
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
Emitter
Density (No. per square mi.)
Fan Song
0.0066
Fire Can
0.0189
Flat Face
0.0046
Long Trough
0.0090
Low Blow
0.0022
Pork Trough
0.0042
Score Board
0.0066
Small Yawn
0.0042
Spoon Rest A
0.0066
Track Dish
0.0028
Wave Kite
0.0004
In Tables 6-2 and 6-3, a final column has been added which gives the num-
ber of sets expected to be operating, or "on", at any given time. These numbers
are determined by the "on times" of the specific emitter functions which have
been assumed as follows:
EW/GCI/ACQ/CS
0.6
BS/HF
0.4
FC/TT/MC/GCA
0.3
ST
0.2
IFF/RS/DT
0.1
Information on the types, number and disposition of emitters associated
with Soviet aircraft and ship targets is available, and is of considerable im-
portance for some aspects of military reconnaissance. For purposes of this
analysis, however, only small harbor craft, patrol boats, and anti-invasion
boats will be considered. It is assumed that the identification and location
of inflight aircraft and the identification and location of capital ships will
not be a normal requirement for the multisensor reconnaissance aircraft. These
functions will be performed by surveillance aircraft, such as the E2A.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
sw~ %W
SPECIAL HANDLING
The emitters associated with Soviet harbor craft are for the most part low-
powered navigation and surface-search radars operating in the vicinity of 3000
and 9000 megacycles, with pulse repetition rates of 400 to 1200 pulses per sec-
ond, and antenna scan rates of approximately 12 revolutions per minute. The
number of such craft is small, so that the effect on densities and traffic is
The fourth source of electromagnetic emissions considered in this analysis
is the communications equipment used by the Soviets. Table 6-4 is a list of
Soviet ground communication equipments used at both tactical and strategic in-
stallations. A remarks column has been included in the table to indicate the
most likely usage of this equipment.
Of the four sources of electromagnetic radiation present in this battlefield
example, the location and identification of signals from communications equipment
would probably be the least useful to the Air Intelligence Officer aboard an air-
craft carrier, since communication equipment is widely distributed throughout the
area of interest, and is not necessarily associated with particular targets or
threats. However, when such signals are intercepted, the ELINT system will in
many cases be able to provide Signal Intelligence (SIGINT) by locating and iden-
tifying the emitter through the analysis of its technical modulation character-
istics. Communications Intelligence (COMINT), involving the analysis of the
semantic content of intercepted communications signals, has not been considered
in this evaluation.
The second geographical area used in this analysis of tactical ELINT target
recognition is North Vietnam. Because of the limited-war activity now taking
place in this country, evaluation of signal radiation present in this battlefield
area is particularly timely and is a true representation of the conditions which
can exist. Also, since the electromagnetic signals emanating from this area are
from only a single source, namely a small population of fixed emitters located
throughout the country, the situation is typical of a very light ELINT environ-
ment which, in conjunction with the dense environment of the previous example,
can provide upper and lower limits of battlefield electromagnetic target
densities.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
%00~ 1w
SPECIAL HANDLING
1
0
cn cd 4-i
10 10
rf1 H
A
CO
r-l
y
a
Cd
0.'
b
?r1 a
P4
ca /
r-1
(1)
H CO
H
cu C.0
',., H L
}a
01
cu
LO
9
CV
P-1
u
0
a W
0
H
4-I ?r1
cd4
?4 -a
CO
C) H
rd ?H
44
Ch 4i
0 cd
41
'C W
+-J
cd
O u
ua4
O O
r-1 CO cj 00 O CV O co
? 1
O 00 O 00100 O O C H O H O H1 O
Q) 00 O
u NOO O
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
vqwo~ Nw
SPECIAL HANDLING
Table 6-5 contains an estimate of the radar emitter population for the
North Vietnam area extrapolated to the year 1967. It is based on present Radar
Order of Battle (ROB) figures, increased by 40 percent to cover some escalation
of activity in the area. It is, of course, impossible to predict what actually
will occur in the complex situation now existing in this area.
6.5 TARGET MATRIX PARAMETERS
By using the information presented in this study, particularly the postu-
lated signal environments, it is possible to draw conclusions concerning the
capability of a tactical ELINT system to identify and locate radiating emitters.
Frequency-pulse repetition frequency plots covering the complete frequency range
of interest are given to indicate how the use of these signal parameters will be
sufficient to identify target emitters with a high order of probability.
Many of the targets listed in Table 1-1 can be recognized by analysis of
the signal radiation pattern of associated emitters. These targets fall in the
groups listed in Table 6-6; the associated radars are listed for each group.
Radars carried by aircraft will normally be active, and thus interceptable,
when the aircraft is airborne.
The usefulness of the ELINT sensor in providing recognition and identifica-
tion data is primarily in the area of activity detection. Large airfields will
be recognized from intercepted GCI and GCA radars associated with them. It is
assumed that this equipment will not be used on small, temporary airfields.
Target detail larger than approximately 3 percent of the target range abeam
the reconnaissance aircraft is resolved.
The accuracy of directional and locational data will be between 1 and 5
percent of the range to target, depending on the system used and the time per-
mitted to make the measurement.
The cueing potential of the ELINT sensor is extremely high against targets
with associated radar and emitting communications equipment.
To determine whether an intercepted emitter signal can be correctly iden-
tified it is first necessary to ascertain whether particular set functions can
be confused with one another. Since frequency and pulse repetition frequency
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
H
4-I
0 0
0
a)cn - w r-4
z
0
H
D C) 0 0 C- LO 0
LL LL O
.. "d cV CV r-I -4 LO (n
ca
0
00
0
cq
o
0
cq
o
r-1
I
r-4
00
CV
m
LO
Lc
G
0
0
I
LO
0
to
00 CC'1
0000
It
oo
o
c7
py
1
1
I
1 1
I
Pa
LC
?
?0
1
c
LL
LC
o
o CD
m
00
ca 00
-
r-I
r-4
>11
?
N
00
ti
N
CO
u
i
d
LO
00
-4
cl
0
00
cq
o,
o
Lf,
0
0
0
It
m
0
00
r-
00
t-
LCD
ec
r-I
t17
w
cq
0J
0
.u
a
o"
a
W
W
W
41
I-i
0
w
rI
0
41
ti)
P4
P4
w
a!
a~
4-1
V1
a)
4-I
Ll
1 4-I
W
0
C,
W
R'+
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
NW
SPECIAL HANDLING
Table 6-6.
Target-Associated Radar Complexes
Target/Threat
Function
Associated Radar
Airfields
GCI
Big Bar, Big Mesh, Slant Mesh, Token
SAM's (SA-2)
SAM's (SA-3)
Seaports
Artillery (AA)
GCA
HF
IFF
TT, MC
ACQ
IFF
TT, MC
ACQ
IFF
CS
AAFC
ACQ
IFF
Home Talk
Rock, Cake, Stone Cake
Witch 4, Witch 5, Fish Net
Fan Song (S and C band)
Spoon Rest A
Score Board
Low Blow
Flat Face
Score Board
Sheet Bend
Fire Can, Whiff
Cross Fork
Fish Net, Score Board, Witch 4
& 5
Artillery (Ground)
FC
BS
ST
Track Dish
Long Trough, Small Yawn
Pork Trough
Aircraft (Fighters)
AI
High Fix, Scan Fix, Scan Can, Scan Odd,
(Bombers)
MC
Scan Odd (Mod), Scan Three, Spin Scan
Komet 3
ACQ
FC
Bombing
& Nav
Puff Ball
Bee Hind
Mushroom, Kobalt
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
(PRF) are two of the more important parameters measured for each signal inter-
ception, plots were made of frequency versus PRF for the emitters listed in
Tables 6-4, 6-5, and 6-6, to determine whether any overlapping areas exist.
These plots are presented in Figs. 6-2, 6-3, 6-4, and 6-5.
It may be seen in Fig. 6-2 that, with the exception of radiosonde emitters,
only EW type radars are found below 150 megacycles, three types of emitters are
found, namely EW, ACQ, and IFF. However, for the frequency range indicated on
this plot, there is no overlapping of any of the emitter functions.
Figure 6-3 covers the frequency range from 550 to 900 megacycles, and here
it may be noted that presently no emitters are found between 215 and 550 mega-
cycles. On this plot there are four distinct emitter functions. The GCI func-
tion appearing on this plot is from the single L-band beam of the BIG BAR and
BIG MESH radars. For this frequency range there are also no ambiguities among
the emitter functions.
In Fig. 6-4 some ambiguities are found in the S-band region. This region
has the highest density of Soviet emitters; therefore, it is expected that some
overlapping will exist in this band. A significant overlapping occurs in the
fire control function region, where it may be noted that an airborne emitter
(Scan Fix) is present. This is the only airborne emitter used by airborne
intercepters (AI) to be found in the S-band region. A second area of overlap
is in the GCI, EW area. This overlapping is expected since EW emitters are very
similar to GCI emitters. As previously mentioned, any EW emitter can perform a
GCI function when operating in combination with a height-finder radar. The re-
maining emitter functions appearing on the plot lie in separate areas and have
no ambiguities with other emitter functions. It may be noted from Fig. 6-4 that
a large gap appears in the region from about 3300 to 4900 megacycles.
Figure 6-5, the final plot of this group, covers the frequency range from
6500 to 10,000 megacycles. In this plot there exists considerable overlapping
of functions within the X-band region from about 9250 to 9500 megacycles. The
major ambiguities in this frequency range are between the tactical emitters
associated with the Soviet CAA and the airborne emitters associated with Soviet
fighter and bomber aircraft. Two other emitter functions also appear in this
region, namely GCI (HOME TALK), and CS (SHEET BEND). The remaining emitter
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
*4100 w
10,000
9000
8000
7000
6000
1000
900
800
700
600
500
400
100
90
80
70
60
50
Fig. 6-2- Soviet radar disposition (No. 1) RF frequency vs
pulse repetition frequency.
SPECIAL HANDLING
SPECIAL HANDLING
FF
ACQ
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
10,090008000,01
7000
6000
1000
900
800
700
600
500
400
100
90
80
40550 600 650 700 750 800 850 900
Fig. 6-3 - Soviet radar disposition (No. 2) RF frequency vs
pulse repetition frequency.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
Nw~ w
SPECIAL HANDLING
1000
900
800
700
600
500
100
90
80
70
60
50
FC
4 GCI
EW ,,
Q EW GCT
Fig. 6-4- Soviet radar disposition (No. 3) RF frequency vs
pulse repetition frequency.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
10,00
9000
8000
7000
6000
5000
0
100
900
0
800
700
10
0
6500 7000 7500 9000 8500 ,9000 9500 10,000
Fig. 6-5- Soviet radar disposition (No. 4) RF frequency vs
pulse repetition frequency.
SPECIAL HANDLING
S
BS
I
TT/MC
=
I
CA
BS
_~
AI
NAV/BOMB
NAV BOMB
Ar.Q
NAV/BOMB
D
NAV/BOMB
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
w
SPECIAL HANDLING
functions appearing on this plot contain no ambiguities. It may also be ob-
served from this plot that a gap appears between 6700 and 8000 megacycles.
The previous discussion has shown that, for the most part, the Soviets have
grouped their emitter functions in separate frequency-PRF regions. This would
indicate that an ELINT sensor can successfully perform the task of target and
threat identification. However, some problem areas do exist in correctly iden-
tifying certain targets and threats because of the overlapping of some emitter
parameters. The most serious of the function ambiguities occurs in the X-band
region where certain ground emitters, having battlefield surveillance and shell
tracking functions, can be mistaken for airborne interceptor radars. This sit-
uation may be a problem to an ELINT reconnaissance system only when the mission
is performed at high altitudes. For low altitude reconnaissance, emissions in
this frequency range would undoubtedly be received from the ground emitters
only. A similar situation occurs within the S-band region where a single air-
borne interceptor emitter appears within a ground fire-control region.
At present no intercepts have been received from any operational emitters
in the frequency range above 10 gigacycles. However, it is known that the
Soviets are doing developmental work in the K-band region and that there will be
traffic in this band sometime in the future. Although the functions of these
developmental emitters are not definitely known, it is felt that their usage
will be for tactical functions, such as battlefield surveillance, shell tracking-
mortar location, tank fire control radars, etc. In addition, some future traffic
may appear within those areas where currently "gaps" appear.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
w
SPECIAL HANDLING
7. TARGET/SENSOR MATRIX
7.1 GENERAL
The target/sensor matrix is an attempt to apply a quantitative evaluation
to each sensor's ability to provide interpretable imagery of the three groups of
targets described in Table 3-2. It is postulated that such a comparative evalu-
ation will provide an indication of which sensors should be used independently or
concurrently against various targets, or which sensors will provide the best in-
formation about the target.
The wide range of variables that can be encountered in a tactical reconnais-
sance operation have been discussed in some detail. In order for a quantitative
evaluation to have any validity, an operational condition must be assumed; devi-
ations from this condition will enhance or degrade the performance of the sensors.
The matrices presented below are based on the assumption that the sortie will be
accomplished under conditions which permit each of the sensors to operate at its
maximum potential. If the matrices were to be used in the field, the many fac-
tors that would degrade this capability would have to be considered, and the ap-
propriate values reduced accordingly.
It is apparent from a study of the preceding discussions of sensor perfor-
mance that altitude has a profound effect on performance. This effect is seen in
image scale, resolution capabilities, object contrasts, areal coverage, image
motion, and other factors. For this reason, two matrices are presented, one for
operations at the 1000 foot altitude range, and the other at the 30,000 foot range.
7.2 MATRIX FORMAT
The sensors are evaluated in terms of their ability to provide interpretable
imagery of each of the three groups of targets defined as "Gross", "Medium", and
SPECIAL HANDLING 7-1
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
*W W
SPECIAL HANDLING
"Fine" located in Table 3-2, and which is repeated here for convenience. These
are listed in the first column of the matrices shown in Table 7-1.
The low altitude matrix lists "Frame Vertical" and "Panoramic/Oblique"
cameras. The frame vertical cameras are assumed to have lenses with 1.5 or
3-inch focal length and to use 70mm square formats. The panoramic camera has a
3-inch lens and. a 70mm by 24-inch format. A 6-inch lens and a 5-inch square for-
mat are used for the oblique camera.
The cameras in the high altitude matrix are grouped according to their scale
range (Medium - 1:;5000 and Small - 1:30000). It is assumed that focal lengths
will range between 12 and 24 inches. Formats will be 9 by 9 inches, 9 by 18 inches,
or (for the panoramic camera) 5 by 40 inches. (It is recognized that cameras with
short focal lengths can be used at high altitude to obtain mapping-type photog-
raphy, but this usage is regarded as being outside the realm of tactical recon-
naissance as defined in this study.)
It is assumed that the radar and infrared systems will be adjusted for opti-
mum performance at each of the two altitude ranges.
Provision is made in the format to evaluate each of the sensors alone, and
both radar and infrared when used together with photography. An evaluation of a
three-sensor combination was attempted, but the results did not materially differ
from those in the two-sensor combinations.
The unique characteristics and capabilities of ELINT sensors are such that
they are not included in the matrices. ELINT records may be of value as a cue
to the interpreter (or the aircrew), in deducing the nature of a target from the
characteristics of associated emitters, and in providing locational information.
In general, it would seem appropriate to assign an increased rating of one point
in any case where ELINT records are available for use with those of any sensor
used independently or in combination.
7.3 QUANTITATIVE EVALUATION
Sensor performance was evaluated in terms of the confidence factor an inter-
preter could place on his identification of the targets in each group. The
numbers 1 to 4 are as follows:
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
SPECIAL HANDLING
Table 3-2. Targets Categorized by Detail Level
GROSS DETAIL -- Targets in this group can be identified from imagery with ground
resolution of not better than 10 feet.
Airfields
(paved runways)
Large open storage areas
Ports and
harbors
Tank farms
Military
installations
Railyards and facilities
Industrial installations
Transportation network
General terrain information
Towns and villages
Large vessels
ICBM/MRBM sites
Large buildings (hangars, etc.)
Large dams
MEDIUM DETAIL - Targets in this group can be identified at ground resolutions
of 2 to 10 feet.
Operational details on targets in
preceding group
Types of vehicles, railroad cars,
aircraft, smaller vessels
Types of materiel in open stores
Underground bunkers; revetments
Large radar antennas
Large weapon emplacements, guns
Sodded airfields, helicopter pads
Minor roads, trails
Passive defenses (trenches, wire, tank
obstacles, etc.)
Trafficability of sectors of transpor-
tation network
Field command posts, bivouacs, camps
Beach gradients, trafficability, exits
Vehicular activity
River ports
Agriculture, vegetation (general in-
formation)
Surface-to-air missiles
FINE DETAIL - Targets in this group can be identified at ground resolutions
better than 2 feet. This group includes components of larger targets; identi-
fication of these components permits a more detailed or exact determination of
the identity and military significance of the "parent" target.
Operational details on the preced-
ing groups of targets
Individual personnel, personnel
shelters, foxholes
Beasts of burden; porter trains
Detailed designation by type and
model of vehicles, weapons, air-
craft, vessels, etc.
Details on crops
SPECIAL HANDLING
Detection of military use of civilian
vehicles, river boats, etc.
Ambush and surveillance sites
Anti-helicopter landing stakes
Cooking fires, campfires
Trails, small streams, fords
Mine fields
Automatic weapon emplacements
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
w
SPECIAL HANDLING
1 - An image can be detected, but the target cannot be identified
2 - The target can be identified as a "possible"
3 - The target can be identified as a "probable"
4 - The target can be positively identified.
A value of 5 is given in some instances of photo-radar and photo-infrared com-
binations. This indicates that radar or infrared records can be used for their
ability to cue, or for their ability to penetrate camouflage or atmospheric con-
ditions, or that an "absolutely positive" identification can be made using both
records to corroborate each other.
in assigning the values described above, it was assumed that the rating
would be valid at least 75 percent of the time. This provision compensates to
some degree for haze, poor illumination, and similar degrading factors.
Some sensor/target combinations do not have a numerical rating. This indi-
cates that the sensor will not produce useful imagery of that target group at
that altitude. On the low altitude matrix, for example, the areal coverage of
the vertical cameras and the radar and infrared sensors is less than would be
required to completely cover most of the targets in Group I in one pass. It is
recognized that less-than-total coverage is adequate to identify many of the tar-
gets in this group, but this capability is taken care of by the evaluation for
Groups II and III.
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
 Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7
1W
SPECIAL HANDLING
Table 7-1. Target/Sensor Matrices
(A) Low Altitude
Group
Frame
Panoramic
Radar
Radar/
IR
IR/Photo
Vertical
Oblique
Photo
I
Gross
3
Detail
II
Medium
4
4
2
5
2
5
Detail
III
Fine
4
4
1
4
1
5
Detail
(B) High Altitude
Group
Small
Medium
Radar
Radar/
IR
IR/Photo
Scale
Scale
Photo
1:30,000
1:15,000
I
Gross
4.
4
2
5
2
5
Detail
II
Medium
4
4
Detail
III
Fine
4
4
Detail
SPECIAL HANDLING
Approved For Release 2010/05/05: CIA-RDP67B00657R000300190001-7