ELECTRONIC

INTELLIGENCE

(ELINT)

AT NSA
Cover Photos: From top to bottom, US Air Force advanced ELINT airborne collection platform; early GRAB 

satellite; Cold War ELINT signals analysis equipment.

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ELECTRONIC INTELLIGENCE

(ELINT) at NSA

Richard L. Bernard

Center for Cryptologic History

National Security Agency

2009
This publication is a product of the National Security 

Agency history program. It presents a historical perspective for informational and educational purposes, 

is the result of independent research, and does not 

necessarily reflect a position of NSA/CSS or any other 

US government entity.
1

Background

What is Electronic Intelligence (ELINT)? ELINT is information 

derived primarily from electronic signals that do not contain 

speech or text (which are considered COMINT).

It is divided into major branches. One branch is Technical 

ELINT (TechELINT), which describes the signal structure, 

emission characteristics, modes of operation, emitter functions, 

and weapons systems associations of such emitters as radars, 

beacons, jammers, and navigational signals.

A main purpose of TechELINT is to obtain signal parameters 

which can define the capabilities and the role that the emitter 

plays in the larger system, such as a ground radar locating aircraft, 

and thus lead to the design of radar detection, countermeasure, 

or counterweapons equipment. The overall process, including 

operation of the countermeasures, is part of electronic warfare.

Another major branch is Operational ELINT (OpELINT), which 

concentrates on locating specific ELINT targets and determining 

the operational patterns of the systems. These results are commonly 

called Electronic Order of Battle (EOB). OpELINT also provides 

threat assessments, often referred to as “tactical ELINT.” OpELINT 

intelligence products support military operational planners and 

tactical military commanders on the battlefield.

A former third major branch of ELINT is the collection, 

processing, and reporting of foreign telemetry signals intelligence 

(TELINT). TELINT is technical and intelligence information 

derived from the intercept, processing, and analysis of foreign 

telemetry. At one time Telemetry Intelligence was considered 

a branch of ELINT since TELINT (later to be called FISINT — 

Foreign Instrumentation Signals Intelligence) activities are closely 

related to TechELINT procedures and were conducted by all of 

the Department of Defense (DoD) military departments. TELINT 

is a critical source of performance information on foreign missiles 
2

and space vehicles while they are being developed and tested. 

TELINT can also provide much operational information on foreign 

satellites and space vehicles. 

Electronic Intelligence (ELINT) at the National Security Agency 

(NSA) did not have an easy start. When NSA was formed in 1952, 

consideration was given to including ELINT as well as COMINT 

as part of NSA’s charter. It is widely believed that Lieutenant 

General Ralph Canine, USA, Director of NSA at that time, felt 

that managing the DoD COMINT efforts would be enough of a 

challenge for NSA. This attitude toward ELINT was shared by the 

DoD military departments — none wanted NSA to manage ELINT; 

each department was very content to manage its own interests in 

ELINT.

Department of Defense ELINT, however, was as much in need 

of coordination and management as COMINT. In particular, the 

effort badly needed a cohesive signal analysis and processing 

effort.

Lieutenant General Ralph Canine, USA, 

first Director of NSA
3

The Start of Modern ELINT

ELINT had its start in World War II with the invention and 

use of radar by the Allies and the Axis. The initial Allied ELINT 

efforts were started by the British; they are described in the book 

The Secret War by Dr. R. V. Jones. The US Army Air Forces had 

a keen interest in ELINT since most of the German radars at the 

time were used to target Allied bombers over Germany, and the air 

forces wanted to know as much about them as possible — including 

how to evade, “jam,” or “spoof” the radars. 

During WWII the US military departments all used ELINT very 

effectively against German ground radars and against Japanese 

airborne, shipborne, and submarine radars. One of the early 1943 

Army Air Force ELINT missions was flown by a B-24 over Kiska 

Island in the Aleutian Islands to electronically map the Japanese 

radars then on the island. In 1944 large numbers of B-24s were 

outfitted with ELINT receivers, which were used to guide jamming 

of the German ground radars in Europe.

Soon after WWII, the USAF in Europe (USAFE) embarked 

on an aggressive TechELINT and OpELINT program, including 

establishing a solid and expansive cooperative program with 

several NATO partners.

In 1952 the US DoD set up the Army-Navy Electronics 

Evaluation Group (ANEEG) to be housed at the Navy’s Nebraska 

Avenue Naval Security Station (NSS) — by coincidence the 

headquarters of NSA at the time — staffed with about thirty people. 

The ANEEG had only informal coordinating collection powers, but 

it was both a centralized analysis point for processing and analysis 

of ELINT intercepts and a focal point for coordination of difficult 

ELINT analytic problems.

In 1955, as ELINT processing problems grew, ANEEG was 

redesignated the National Technical Processing Center (NTPC), 

under the USAF Air Staff, and administratively was designated 
4

AFCIN-Z; it was housed in Building 20 at the Naval Security Station 

in Washington, DC. In addition to Army and Navy participation, 

the NTPC had key participants from the USAF and from the CIA. 

CIA at that time was operating the U-2 airborne reconnaissance 

program, and it led the integration of U-2 data into NTPC signal 

processing efforts. The U-2 had ELINT signal collection packages 

as well as photographic sensors.

Direction for NSA to Manage DoD ELINT

Starting in 1954, a number of presidential-level committees 

recommended that ELINT be brought under NSA’s purview. 

Both the Mark Clark Subcommittee of the Hoover Commission 

in 1954 and the William O. Baker Committee in 1957 made 

such a recommendation. Dr. Baker was a major influence in 

having US ELINT efforts managed by NSA. Strongly backed by 

President Eisenhower, the Baker Committee’s efforts culminated 

in the issuance of National Security Council Intelligence Directive 

(NSCID) No. 6, “Communications Intelligence and Electronics 

Intelligence,” in early 1958.

Naval Security Station (NSS) at Nebraska Avenue in

Washington, DC, home of the NTPC
5

NSCID No.6 gave NSA many 

ELINT powers. Within DoD it was 

implemented in early 1959 by an 

updated 1955 DoD Directive S-3115.2 

and focused DoD top management 

review within DDR&E, soon to be 

headed by Dr. Eugene Fubini, a staunch 

supporter of ELINT and of having NSA 

manage DoD ELINT. It gave NSA (with 

certain exceptions) “operational and 

technical control” of all US DoD ELINT 

activities. The directive made it quite 

clear that the Joint Chiefs of Staff, 

component commanders, and the 

military departments and services were 

to fully support these NSA-managed 

ELINT activities.

ELINT Management Begins at NSA

One of the first actions taken in response to the DoD ELINT 

directive in March of 1959 was to incorporate the National 

Technical Processing Center into the NSA Collection and Signal 

Analysis (COSA) organization as the “Non-communications Signals 

Analysis and Processing Division.” By 1959, NTPC had about 100 

people. This signal processing and analysis group formed the core 

of the NSA effort at that time.

Some of the DoD military departments and combat commands 

were not greatly enthusiastic about NSA’s new responsibilities, and 

as a result many management problems and effective coordination 

procedures developed. The Strategic Air Command (SAC) was 

long accustomed to doing ELINT business “their way,” which was 

tailored to fulfill their mission. SAC soon developed a productive 

and cooperative set of arrangements with NSA.

Dr. William O. Baker
6

SAC had an extremely active ELINT program using RB-47 

aircraft (the reconnaissance version of the B-47 bomber) to probe 

Soviet aircraft defenses in order to get information to protect SAC’s 

fleet of B-52 bombers. All of the SAC B-52s were soon protected 

with “radar warning receivers” based on ELINT information.

In 1960, two major overseas 

ELINT processing centers 

became integral parts of the 

overall DoD ELINT structure 

NSA developed. These centers 

processed and analyzed data 

primarily from the US military 

departments’ ELINT collection 

assets. In 1974 the USAF Europe 

sponsored programs with 

NATO partners and was fully 

integrated into the NSA system. 

Later this effort was combined 

with the NSA engineering 

support office in Europe.

NSA Fort Meade complex in the 1960s

Now-closed STONEHOUSE 

deep space TELINT facility
7

NSA built and deployed — or sponsored — many ELINT and 

TELINT signal collection systems during the 1960s. A ring of 

sophisticated systems was developed and deployed in the TELINT 

area to gather information on the missile development and space 

activities of the Soviet Union. 

Since the early 1960s, NSA had been a participant in the NRO 

and US Navy-led GRAB and POPPY efforts to collect ELINT on 

Soviet air defense radar signals 

from an orbiting satellite. 

Intelligence from GRAB and 

POPPY provided the location 

and capabilities of Soviet radar 

sites and ocean surveillance 

information to the US Navy and 

for use by the USAF. This effort 

provided significant ELINT 

support to US forces throughout 

the war in Vietnam.

One of NSA’s new 

responsibilities was to prepare 

a National ELINT Plan (NEP) 

in coordination with the ELINT 

community at that time. The 

first plan was completed in 1963 

under NSA leadership with the participation of the US military 

departments, the Joint Chiefs of Staff (JCS), DIA, and CIA. Several 

plans followed.

Another response by NSA related to the expansion of NSA 

ELINT responsibilities was the creation in 1967 of a special group 

called DAGER, the Director’s Advisory Group on ELINT and 

Reconnaissance. It was a small group headed by Mr. Charles Tevis, 

who originated the idea and was a strong proponent and technical 

leader of NSA’s stewardship of ELINT. 

Early GRAB satellite for 

ELINT signal collection from 

ground radars
8

In the late 1960s during the Vietnam War, ELINT played 

a major role: many military airplanes were outfitted with 

warning receivers and jamming equipment to counter the North 

Vietnamese antiaircraft guns and surface-to-air missile sites 

provided to North Vietnam by the Soviets. This radar warning 

and associated jamming equipment significantly reduced US 

aircraft losses. One of the key aircraft used was the Navy A-3 

SKYWARRIOR, which could be aircraft-carrier-based. When 

configured for electronic warfare, it was designated EA-3B. 

The EA-3B was particularly effective against the 

Soviet-built SA-2 surface-to-air missile systems which 

targeted US fighters and bombers over North Vietnam.

The EA-3Bs remained in service until the early 1990s and 

served around the world as ELINT and electronic warfare aircraft; 

they were based on land and on carriers. The aircraft were used 

in the 1991 Gulf War and helped target Iraqi antiaircraft missile 

systems for allied air-to-ground missile destruction. 

In the early 1970s a joint National Reconnaissance Organization 

(NRO) and NSA field ELINT processing center was opened. 

This joint effort added NSA’s expertise in signal processing 

EA-3B ELINT and electronic warfare 

aircraft
9

and its reporting responsibilities to NRO activities, provided 

many collection and processing advantages, and improved timely 

reporting of NRO collection results.

Expansion of NSA ELINT Responsibilities

In 1971 the Collection and Signals Analysis organization, 

elements of the Research and Development organization, 

and other SIGINT operational elements merged to form the 

“Electronic Intelligence and Systems Management Group.” This 

group provided a good institutional base for NSA to manage 

ELINT, including collection activities and the development of new 

collection and processing systems for ELINT efforts. Similarly, 

it created a cohesive way to develop the ELINT portion of the 

Combined Cryptologic Program (CCP) program and budgets with 

the DoD military departments. One of the offices in the group 

concentrated on TechELINT, one on OpELINT, and one on 

TELINT.

TELINT attained its status as a separate “INT” in 1971 with the 

publication of the revised DoD Directive 5100.20, which gave NSA 

its updated charter. TELINT activities were focused in the NSA 

organization as the Advanced Weapons and Space Systems Office 

within the new group.

By the early 1970s NSA had completed a network of groundbased foreign telemetry collection facilities and worked with the 

SA-2 “Guideline” groundto-air missile 

system
10

DoD military departments and services to develop aircraft and 

shipborne TELINT signal collection facilities. 

National Security Council 

Intelligence Directive No.6 

was updated in 1972 and 

retitled “Signals Intelligence 

(SIGINT).” This directive 

gave NSA even more ELINT 

powers. Based on NSCID 

6 concepts, SIGINT within 

DoD had been implemented 

by Department of Defense 

Directive 5100.20, issued in 

1971 and commonly referred 

to as the “NSA Charter.” 

The DoD Directive charged 

NSA with the responsibility 

of managing SIGINT within 

DoD and specifically defined 

SIGINT as including COMINT, 

ELINT, and TELINT. As 

previously mentioned, the 

term TELINT has fallen into 

disuse and has been replaced 

by the term FISINT, which 

includes telemetry, missile and 

satellite command signals, and 

beacons.

During the Cold War years, NSA continued to sponsor — or 

participate with the DoD military departments, the National 

Reconnaissance Office, and the CIA in — the development of 

sophisticated signal collection equipment for target signals to keep 

pace with the ever-changing technology of those signals. 

One of the premier ELINT data collection platforms is a modified 

US Air Force RC-135U aircraft. The primary function of these 

TELINT signal collection 

position in early 1970s
11

TechELINT specially configured aircraft is ELINT reconnaissance 

and surveillance. They collect, analyze, and sometimes locate 

foreign target electronic signals to help determine detailed 

operating characteristics and capabilities. They have been in 

operation, with a continuing series of advanced configurations, 

since 1964.

Now-closed 1970s missile and space TELINT facility

Modified RC-135U advanced ELINT airborne collection

platform
12

Another long-time ELINT collection platform is the US Army 

GUARDRAIL aircraft. This aircraft is configured to locate enemy 

fire control radars and thus provide OpELINT. The aircraft can fly 

near or over a battlefield and communicate directly with Army and 

Air Force units. The GUARDRAIL collection and related analysis 

and reporting efforts have served in conflicts starting with the 

Vietnam War through DESERT STORM in 1991.

During the Cold War many technological advances were made 

in ELINT collection and analysis equipment. These advances made 

increased capabilities possible with more reliable configurations 

and by consuming less electrical power. As the “state-of-the-art” 

of foreign radar and other electronic equipment advanced, ELINT 

receivers had to keep pace. One such receiver, developed in the 

1970s for both ground site and airborne use, was the QRC-259. 

Some thirty to forty receiver systems were deployed and operated 

into the 1990s.

NSA also continued to modernize and expand its ELINT 

signals processing and analysis equipment “positions.” The 

Agency likewise upgraded positions at selected field facilities with 

emphasis on more timely reporting of ELINT results.

NSA also developed and operated special-purpose telemetry 

processing equipment, often computer-based, in the National 

Telemetry Processing Center (using the abbreviation NTPC). 

RC12 GUARDRAIL COMINT and ELINT collection platform
13

Different types of equipment sets were needed to process and 

analyze different forms of telemetry used by various telemetry 

transmission equipment. One example is RISSMAN, a specialpurpose telemetry processing system used at NSA during the Cold 

War.

QRC-259 ELINT signal receiver developed in the 1970s

RISSMAN, a special-purpose telemetry processor
14

Summary

Starting in 1958, and working with other US and allied ELINT 

organizations, NSA technical and management initiatives and 

expertise have made significant intelligence gains for the United 

States and its allies. These gains provided vital intelligence 

information for use by electronic warfare equipment designers and 

operating personnel. They also provided critical information on 

foreign missiles and space vehicles that were a threat to the United 

States. NSA continues today in its role as the lead US organization 

for ELINT matters.

About the Author

Richard Bernard is a consultant and volunteer in the NSA 

Center for Cryptologic History (CCH). He has held a number 

of ELINT planning, engineering, and operational positions at 

NSA. He has been a member of the Association of Old Crows, an 

electronic warfare technical association, since 1979.

Cold War ELINT signals analysis equipment set operated 

at NSA