ELINT A SCIENTIFIC INTELLIGENCE SYSTEM CHARLES A. KROGER, JR.

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP62-00634A000200010001-6
• Release Decision: RIFPUB
• Original Classification: S
• Document Page Count: 13
• Document Creation Date: December 19, 2016
• Document Release Date: September 30, 2005
• Sequence Number: 1
• Content Type: REPORT

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Date: By; 2'L
INT
A SCIENTIFIC INTELLIGENCE SYSTEM
Charles A. Kroger, Jr.
During the initial phases of the Battle of Britain a German
bomber, relatively safe under cover of darkness, flew over the
blacked-out landscape heading for London. At a specific mo-
ment the bomber dropped its bombs, which accurately hit their
target, and another successful German Luftwaffe attack was
history. Electronic advancements by the Germans made this
possible. British interception and analysis of this new elec-
tronic bombing device countered the Germans' success and
continued to render less effective every subsequent electronic
advantage the Germans developed. In a parallel manner the
Germans developed a highly effective electronic intelligence
effort directed against the Allied raids originating from Britain.
This phase of electronic intelligence, utilizing electronic means
to determine enemy electronic capabilities, began in England
just before World War II. and has been an ever increasing effort
which today is called ELINT.
ELINT is a coined word for the process of electronic intercept
and analysis or electronic intelligence - a process about which
very little has been written. The intelligence officer, unless he
is in the electronics field himself, has had little contact with
ELINT: By directive ELINT is defined as : "the collection
(observation and recording), and the technical processing for
later intelligence purposes, of information on foreign, non-
communications, electromagnetic radiations emanating from
other than atomic detonation sources." In simple terms,
ELINT is the detection and analysis of radiations from foreign
electronic devices for the purpose of extracting information of
value to intelligence.
Just as a flashlight radiates a beam of light observable to the
human eye, electronic devices emit or radiate nonvisible, non-
audible radiations which are detectable and recordable, using
electronic devices just as the human ear hears sound. This
? interception or collection of enemy radiations is the first stage
of ELINT.
? The formal definition restricts ELINT to "noncommunica-
tion electromagnetic radiations other than atomic detonation
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sources." This means that ELINT is responsible for all radia-
tions except those used in voice or other communications such
as radio or telegraph and those resulting from atomic sources.
What other kind of radiations are there? To name a few with
which ELINT deals, there are radiations from missiles and mis-
sileguidance devices, radiations from developmeiital_ labora-
tories and field testing stations working on ktronic devices,
ra ar, navigational .aids, anti-aircraft and eraft gun direc-
tion, air-to-air or air-to-ground identification sgn1s, and so on.
"Technical processing for later intelligence purposes" means
subjecting the collected ELINT raw data, usually in the form
of beeps on a magnetic tape or wire, to a detailed analysis by
use of complex electronic equipment. This equipment permits
the analyst to hear with his ears, to see on an ogQUJQ=Qpe, to
measure very accurately, to photograph, to con are with
standards and to investigate the intercepted signal in as many
ways as are necessary to identify the characteristics of the
foreign device. When the "technical processing" is completed
the technical analyst can pass to the intelligence analyst de-
tailed information on the location and capabilities of the for-
eign device. The intelligence community can then combine
this information with other knowledge to estimate the over-all
competence and possible intentions of foreign powers.
For a technical look at what ELINT really is let us turn for
a moment to basic physics. Here we remember that electro-
magnetic energy, like light, travels in waves. These waves vary
in length and form a spectrum. We are all familiar with the
rainbow with its colors ranging from red, having waves of 760
millimicrons in length (400 million megacycles/sec), to violet,
with waves of 385 millimicrons in length (800 million mega-
cycles/sec). This color spectrum is a part of the electromag-
netic spectrum. The radio portion of this electromagnetic
spectrum is used primarily for communications and military
weapons. Currently the military weapons use radio waves
varying from a few thousand cycles (waves per second) up to
100 kilomegacycles (one hundred billion waves per second).
The following diagram illustrates the position of the radio and
color spectrums in the over-all electromagnetic spectrum and
an expansion of the radio spectrum showing the bands where
different Soviet electronic devices radiate.
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FREQUENCY _ _
)RAVES PER SECOND) 102 IOI 10 lot I D 2
AIRCRAFT
COMMUNICATIONS
RADAR AND GAGE 8
GUIDANCE I RADARS
V T FUSES
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For a specific example of how ELINT works, let us take a
simplified look at Soviet radar. Soviet radar devices radiate
electronic impulses at certain frequencies and in definite beams
searching the sky for long distances and great altitudes for any
object that may be present. When these impulses strike an
object they bounce off and return to a ground or airborne re-
ceiver which calculates the length of time between emission
and reception and the strength of the signal received. From
this, the Soviet radar operator can generally tell the size, speed,
direction, altitude, and other pertinent information about the
unseen object. Our Strategic Air Command, with its retalia-
tory mission, urgently requires every possible bit of information
on Soviet radars - particularly on their location and capa-
bility. This is where ELINT goes to work. By intercepting,
amplifying, recording and analyzing an enemy radar signal or
pulse, we can learn all about it. By studying the type of radi-
ation, its modulation (AM, FM, pulse) its pulse repetition rate,
pulse duration, pulse shape, its radio frequency (position on
the electronic spectrum), its antenna pattern characteristics,
and so on, we can identify the radar, compare it with known
information, ascertain its range, location, use, and other essen-
tial information required to evaluate its capability as a radar
and its susceptibility to countermeasures.
This same process of ELINT pertains to any and all enemy
electronic devices including airborne intercept devices used by
guided missiles, guided missile launchers, fighter aircraft, long-
range and short-range navigational aids, ground controlled in-
tercept height finders, anti-aircraft and aircraft fire control
radar, blind bombing devices, electronic radiations emanating
from scientific laboratories or production plants, and so on.
What do these radiated signals sound like? Frankly they
sound like noise or radio static during a thunder storm - in
fact, before the more euphonious term of ELINT was coined, the
British called it "Noise Listening" and, during World War II,
had a "Noise Listening Bureau."
Although ELINT is a very complex field - constantly looking
beyond present knowledge of electronics to fulfill its role of pro-
viding timely information on new foreign electronic develop-
ments, it need not be pushed aside as too complicated to be
understood. Because of its complexity, some members of the
intelligence community are inclined to throw up their hands
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and ignore this potential tool. However, ELINT is not too
is it _e>?ain ' n1f, but it
difficult to comprehend or use, nor _
can ~._ _____ _ contribute essential, accurate in
gence process.
Scientific intelligence and, in particular, ELINT, or electronic
intelligence, had its start in England immediately before World
War II. Early in 1939 the British Committee for the Scientific
Study of Air Defense first drew attention to Britain's ignorance
of new German weapons. One scientist, Dr. R. V. Jones, was
appointed to look into the matter. Before he even started his
task the war broke out and in June 1940, Dr. Jones, after con-
siderable study, concluded that the Germans had developed a
radio beam by which their bombers could operate over England
regardless of weather, darkness, or cloud cover and still be most
accurate in their blind bombing. This beam, just a little more
than one-half mile wide, passed directly over London. Based
on Dr. Jones' conclusion, steps were immediately taken to find
any possible countermeasures. A Royal Air Force search air-
craft was outfitted and it accomplished its mission of looking
for and detecting this German beam. Technical analysis of
this information provided the radio frequency and other char-
acteristics of the beam, thus permitting the British to 'am it
and render it ineffective. Henceforth, many bombs intended
for London fell harmlessly on the open countryside. This in-
terception and analysis of an enemy electronic radiation (later
known as Knicklbein) was the birth of present day ELINT.
The Germans altered their beam system and soon began using
a better system utilizing intersecting beams referred to as the
"X" apparatus, which provided greater accuracy. These beams
were at a different frequency than Knicklbein, requiring new
search and analysis before the British solved this new threat
and took countermeasures. With the "X" apparatus, the
bomber flew along an electronic beam while its position along
the beam was observed from a German radar station on the
continent. When the bomber was over the target, it was told
to drop its bombs. By now Britain's ELINT capability of inter-
cepting and analyzing this electronic information was quite
effective and continued to grow in scope and importance
throughout the war.
During World War II the US made extensive use of electronic
intercept devices in both the Pacific and European Theatres of
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Operation. Special USAF and Navy planes equipped with
ELINT receivers ferreted out the secrets of German and Jap-
anese antiaircraft radar and aircraft warning devices. From
the use of such planes the word "fgrret" was coined, a term
presently applied to aircraft equipped to investigate enemy
electronic radiations. Among the most deadly weapons di-
rected against the Eighth Air Force were the German antiair-
craft guns which were equipped with extremely accurate radar
directors known as "Wurzbergs." The close formations of
American aircraft made a juicy target for the more than 16,000
German antiaircraft guns. By use of radar intercept equip-
ment (ELINT equipment) information was obtained which per-
mitted the use of jamming devices, and thus the one-billion
,.dollar-investment of the Germans in their Wurzberg radars was
literally ruined by the countermeasures made possible through
ELINT. Knowing we had this capability, the Germans began
a frantic search for non-iammable r_adar-equipment, but the
war was over before they succeeded.
Following World War II there was a period in which interest
in ELINT, as in many wartime activities, tapered off. Some
effort continued but the real push to provide intelligence on
electronic advancements in other countries was not initiated
until the USSR clamped down its Iron Curtain. Since that
time, the c ollectiga..arld aaa_ Isis of electronic signals radiating
behind t_ he Curtain?,s been the constant goal of ELINT. Since
the birth of ELINT in 1940 the effort has grown in size, cost.
importance, complexity, coverage, and capability, and, like
most scientific efforts, is making yesterday's limits, today's
capabilities.
Electronic intercept, to use one connotation of ELINT, ro-
vides factual information. Unlike the collection of much in-
telligence information where we are forced to rely on word of
mouth, memory, or integrity of source, electronic radiations are
intercepted and recorded by machine. If a signal is being radi-
ated it can be recorded and later reported accurately even by
someone who doesn't understand all that he is doing. Because
of this factual nature, ELINT has provided substantiation
many intelligence estimates based on other intelligence
processes.
During World War II, Air Force B-24 aircraft and radar-
equipped Navy Catalina aircraft were assigned the job of locat-
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ing enemy radar in the Pacific. They spotted and pinpointed
Japanese air warning sets scattered all the way from the Solo-
mons to the China coast. A few days before the Leyte landing
in October 1944 one of the ferrets discovered a new Japanese
radar on Suluan Island at the mouth of the Leyte gulf. As
this radar commanded the approaches to the Leyte coast line
it was necessary to eliminate it and this was done on a com-
mando raid by the US Rangers.
Currently, ELINT is providing the Strategic Air Command
with the intelligence it requires on the location and range of
Soviet radar. Through ELINT, information is acquired on the
method..g&pabiljy, and limitations of Soviet long-rage navi
ation sYstms upon which their atomic bombers rely. Soviet
missile tests are monitored by ELINT and the point may soon
be reached where, byInterception and analysis of the telemeter-
ing signal from Soviet missiles, we will acquire missile per-
formance data vital to our National Intelligence Estimates.
(Telemetering is the electronic system used in missile testing
which records, codes, and transmits to ground test stations such
things as missile speed, flight path, guidance, skin tempera-
tures, and other behavior characteristics of the missile in
flight.)
Since early in World War II the Army, Navy, and Air Force
each have expended varying degrees of effort on ELINT, and in
1952 the Central Intelligence Agency entered the ELINT field.
Although much of this individual endeavor was valuable, in
1954 better organization was given to ELINT - organization
on a national level. The lack of proper dissemination of val-
uable intelligence produced by one organization but not always
readily available to the others in the community was noted as a
serious problem. When this situation came to the attention of
the National Security Council a study was made, and National
Security Council Intelligence 'Directive No. 17, entitled Elec-
tronic Intelligence (ELINT) was issued (in May 1955).
NSCID-17 established the first national policy for ELINT and
it is still the basic authority for the national ELINT program.
It directed that:
a. The US Communications Intelligence Board
(USCIB) shall be the national policy body for ELINT.
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b. The Department of Defense and the Central In-
telligence Agency shall be responsible for their respec-
tive ELINT collection activities.
c. The technical processing of all ELINT shall be
accomplished in a jointly-staffed center administered
by the Department of Defense.
d. All data collected by the collection agencies shall
be made available to the National Technical Process-
ing Center (NTPC).
e. The NTPC shall effect the fullest and most expe-
ditious processing possible and furnish the results to
the interested agencies.
The present national organization for ELINT is rather com-
plex, with many interlocking organizations and many formal
and informal coordinating committees. The important con-
sideration is that ea of the services and CIA is free to run-iits
own collection nnara ,ions designed to furnish information it
alone reouires, but is expected to submit all collected data to
the NTPC subject, only to the .mii~lmumdelays necessitated by
prior exploitation for urgent tactical or.operational purposes.
One can immediately see the strong vertical organization for
ELINT within each major component. It should also be appre-
ciated that much horizontal collaboration is being accom-
plished by joint participation in such organizations as the
NTPC and AFOIN-Z in an effort to coordinate individual activi-
ties into a national ELINT program.
In October 1953 a study was made of ELINT in CIA. This
resulted in the appointment of an Agency ELINT staff officer
and in the preparation of an Agency ELINT program which the
Director of Central Intelligence approved on 29 May 1954.
Within the Agency ELINT is organized generally as follows.
The Ojlice of cientific Intelligence develops targets and
requirements for ELINT collection, furnishes scientific and
technical guidance to Agency collectors, and performs the tech-
nical analysis and collation of ELINT with all source material
in the production of scientific intelligence. The Clandestine
Services conducts a continuing review of the potential and
.NOW
capabilities for covert ELINT collection, implements specific
clandestine activity in response to approved ELINT require-
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ments, and coordinates US ELINT clandestine activities with
foreign governments. The Office of Communications arranges
for research, development, and procurement of ELINT equip-
ment as required to support clandestine ELINT collection. The
CIA ELINT Staff Officer advises the Deputy Director of Central
Intelligence and appropriate operating components on the
formulation, implementation, and coordination of ELINT
plans, policies, and programs.
On the national level, much work has gone into summarizing
what each organization requires in the way of information on
enemy electronic developments. This sizeable task has re-
sulted in a formal statement of the currently definable Specific
ELINT Collection Requirements (FFEQQR). This collection
guide is based on the priority of the National Intelligence Ob-
jectives. It has been disseminated throughout the services and
CIA field units for guidance as to what information the intelli-
gence community requires and in what priority.
To realize the need for an adequate requirements system,
consider that the ideal ELINT system is one capable of collect-
ing all signals of interest and extracting all of the useful infor-
mation from each signal. This is neither possible nor prac-
ticable, however. The questions of just what signals are of
interest and just what information about them is needed must
be answered in the light of the gaps in our intelligence. Thus,
as in other branches of technical intelligence, ELINT is faced
with the problem of relating scientific techniques to intelli-
gence problems.
In general, ELINT targets fall into two major categories.
The Army, Navy, and Air Force, charged with the military de-
fense of our country, are primarily concerned with the location
and capability of all enemy radar on a current basis. This is
referred to as the Radar Order of Battle (ROB} . The Air
Force, for instance, must know where the heavy concentrations
of enemy radar are so that its planes can either skirt the area
or take proper countermeasures. The largest portion of inter-
cepted enemy electronic information falls into this category of
maintaining an adequate radar order of battle. CIA, on the
other hand, is primarily interested in scientific break-thr ugh,
or in not being surprised by new enemy electronic develop-
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ments. This means that most ELINT effort is directed toward
the rote ption and analysis of new and unusual electronic
signals. Naturally in the course of searching or new and un-
u ua ignals, much order of battle information is received.
This serves, in addition to supplementing the services opera-
tions, as a basis of comparison to determine what is new and
unusual. The ELINT objectives of first priority to CIA relate
to those signals which have yet to be intercepted or for which
the radiating source has yet to be seen. Specifically, the
targets are as follows:
a. Those non-communication signals which are, or
are suspected to be, associated with the Soviet or
Satellite ability to deliver atomic or other weapons of
destruction - that is, guidance or telemetry signals
associated with missiles, airborne navigation, and
bombing systems.
b. Those non-communication signals which are or
are suspected to be associated with the Soviet or Satel-
lite ability to defend their countries against the deliv-
ery of atomic or other weapons of destruction -that is,
early warning, ground-control intercept, gap-filling
radars, surface-to-air weapons systems, airborne weap-
ons systems, ground surveillance systems, jammers,
and so forth.
c. Those signals occupying an unusual portion of
the radio frequency spectrum not normally associated
with Soviet or Satellite equipment.
The equipment involved in ELINT is elaborate and com-
plex. To make matters worse, the higher up the frequency
spectrum you go the shorter your intercept range becomes,
and the present trend toward higher frequencies means that
ELINT equipment must get closer to the target or be designed
with greater ranges, both of which approach the impossible.
ELINT equipment falls into two main catagories: collection
uea ipment (airborne, maritime, fixed station, or agent-carried)
and nal sis Went (used on the ground to reproduce,
readout, and analyze the collected information). Basically,
the major components of an ELINT collection system are the
antenna, receiver, recorder, direction finder, and analyzer.
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The antenna corresponds to the human ear. It is that com-
ponent which first detects a signal. It is, of course, desirable
that the antenna be very sensitive or, as we say in ELINT, have
high antenna gain. This permits the maximum intercept
range. The ideal antenna system would have the following
characteristics :
a. a continuous and fixed broad area coverage,
? b. very broad electronic spectrum coverage,
c. very high gain,
d. inherent capability for giving directional in-
formation.
These requirements are not all compatible. In practice it is
necessary to compromise in order to gain a workable system.
The decision as to which of the desirable characteristics can
be safely compromised, and to what extent, is based on the fre-
quency range of interest and also on the specific ELINT target
under consideration. For instance, broad area coverage may
be obtained by either of two means - a broad beam antenna
fixed in space or a narrow beam, scanning antenna. The first
method demands a sacrifice in gain. The second limits the
time coverage of any part of the total area.
Following receipt of the signal by the antenna it is passed to
a receiver. The function of the receiver is to convert trans-
mitted information available at the antenna into a form that
can be measured and recorded. Basically two general types of
receivers are in use today - the superheterodyne and the
crystal video. The operating characteristics of each receiver
may be outlined as follows :
Superheterodyne - slow scan.
a. inherently high sensitivity,
b. good frequency resolution,
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c. prohibitively long search time in many cases.
Crystal video - wide open.
a. low sensitivity reducing maximum probable
range,
b. frequency resolution problems,
c. search time considerably less than the super-
heterodyne.
From the receiver the signal goes next to the recorder where
the signal is stored on magnetic tape or wire. There are two
main reasons for recording signals. A permanent record of the
signal is required for future analysis and for records, and on
signals of short duration or higher complexity the operator
may not have enough time or capability to evaluate the signal
parameters before the transmission is ended.
Direction-finding equipment is sometimes utilized during the
interception of the signal. It displays incoming signals on an
oscilloscope or other azimuth-reading device giving the direc-
tion of the arrival of the signal.
Analyzers in the ELINT collection system are sometimes used
during interception to provide a preliminary observation of the
type of modulation and to measure the repetition rate, dura-
tion, and general shape of signal pulses. Signals are usually
presented by a cathode ray tube (similar to a television screen),
which provides a moving picture of the shape, size, and nature
of the incoming signal pulse or wave form. The pictures are
usually photographed as a permanent record. It should be
pointed out that ELINT collection devices need not be huge
in size, as are those used in ground, sea, and some airborne
operations. Quite to the contrary, considerable use is made of
miniature equipment no larger than a book. ELINT collection
equipment is usually designed for the specific situation in-
volved, whether it be a 60-foot parabolic antenna on the ground
or a tiny, unassuming, hand-carried package.
The major components of an ELINT analysis system vary
greatly with the purpose of the analysis. Order-of-battle
analysis is often done automatically by IBM-type equipment.
The analysis that CIA performs is not for order of battle but is
to identify new and unusual signals. For this, man-operated
equipment is required and an analysis positioncontains atleast
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TO PLAY TAPE LOCATION ON
FROM RECORDER FREQUENCY
SP ECTNDM
NUMBER OF AND SIGNAL BEAM WIDTH
SPACE BETWEEN AND ROTATION AND/OR
SIGNALS NOD RATE
the following fundamental equipment: a tape transport used
for duplicating or monitoring; a counter that measures and
illustrates the modulation frequency; an ink-on-paper recorder
to draw a continuous trace of the signal amplitude; an oscil-
loscope, which permits observation of the wave form; a vibra-
lizer to display modulation frequency components versus time;
filters to separate signals; a rapid-advance movie camera; and
a host of other equipment to permit the analyst to scan great
volumes of tape and film to separate that minute portion which,
upon detailed analysis, may prove to be a new electronic devel-
opment.
It is hoped that this basic discussion of ELINT will provide a
general concept of this complex scientific intelligence process.
It should be realized that in the interest of readability many
points have been simplified and technical details omitted so as
not to confuse the non-technical reader.
If one considers that one-third of the cost of a modern fighter
aircraft goes for electronic equipment and that most of the
electronic devices which make up this equipment radiate sig-
nals, then one begins to understand how much there is to learn
of Soviet capabilities by examining their use of electronics.
This also applies to ground and sea weapons, including missiles.
Recent news reports of Soviet developments in the scientific
field demonstrate how heavily the Russians are relying on elec-
tronics and how advanced their development is. The Soviet
earth satellites with their radiated signals are a responsibi ityw
of ELIlT. ELIN'I} mus continue o intercept and to analyze
Soviet electromagnetic emissions preferably in the research and
development stages in order to keep abreast of Soviet electronic
advancements and to attempt to predict future capabilities.
TAPE
TRANSPORT
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