Electronic Intelligence (ELINT & SIGINT)
Precise characteristics and locations of Emitter Signals
Signal Intelligence (SIGINT)
SR-71's Mach 3 speed during its normal operational mission profiles created a
very beneficial side effect which was to stimulate the enemy's radars and
missile systems. Their responses to the Blackbird's flight path resulted in
jamming, missile system tracking, and other electronic activity. The electronic
signals generated during these responses were collected by the SR-71's own
Electro-Magnetic Reconnaissance (EMR) System as well as other collection assets propositioned
in the area at the time. The enemy's capabilities and frequencies used for each
radar or missile site were then recorded and documented revealing the enemy's
battle plan. The EMR System was installed in the K and L mission bays. In
the 1970s, funding was available for an improvement to the system, so its
replacement was come to be known as the Elint-Improvement Program (EIP) System
and was installed in S and T mission bays. This new location enabled the system
to be flown on both photo and radar missions. The
manufacturer for the EMR/EIP was AIL Systems.
Advanced Synthetic Aperture Radar System (ASARS1)
Manufacturer: Goodyear Aerospace in Litchfield Park, AZ. and then Lockheed Martin Corporation
High Resolution Radar Imagery
(Detachable Nose component)
Defense Systems (DEF)
Provides ground-to-air and air-to-air missile protection. Still Classified
Def systems were labeled DEF A,B,C,E and G. Later modifications to the DEF Systems resulted in DEF A2, C2, H and M systems. Nearing retirement of the SR-71, a programmable DEF labeled A2C could defeat all known threats to the Blackbirds.
DEF System Storyboard
(Photos Courtesy of Evergreen Aviation Museum, McMinnville, Oregon)
Photo Courtesy of Buz Carpenter
"A2C" System, Manufacturer ITT, and the DEF "C" System
(Right grey vertical Unit) Manufacture:
DEF A2C, C and H Systems were used during the reactivation period of the program
1994-2000. The A2C System replaced the DEF A2 System from the earlier
years. The DEF A2C is pictured mounted to the D-Bay mission door for
display purposes. It would normally be hard-mounted in the D-Bay.
DEF "H" System
“H” System, Manufacturer: Northrop, probably one of the highest power
jammers of its time, could be installed in the K or P Mission bays depending on
mission type, photo or radar. After the replacement of the EMR with the
EIP Elint system, the DEF H would be installed in K-Bay, freeing up P-Bay for
the TEOC camera to be used on both photo and radar missions.
AR1700 DEF and ELINT Recorder
14-Track Analog Recorder, Manufacturer: AMPEX, mounted in the M Mission Bay.
Pictured above is the installation configuration used during the reactivation
period. The AR1700 recorded information from the Elint and DEF systems.
It could be turned on by the Elint system or by the RSO via the Power and Sensor
Control Panel. During the earlier operational years, it was paired up with
a “Digital Recorder” manufactured by RCA which was the primary Elint data
AR1700 Recorder Open
Universal DEF Control Panel (UDCP) installed in the aft cockpit for the RSO to operate the DEF systems. Note that all classified placards have been removed & blacked blank display readouts installed.
Editors Note: Credit goes out to Mike Hull for the correct identification of the DEF units pictured above. Mike worked the DEF/Elint systems for 20 years, including the reactivation period 1994-2000. Through his expertise, he provided Evergreen Museum with the demilled units for public display at the Museum. Additionally, Bill Whittle and Mike Hull provided three other sets of DEF equipment to The Air Force museum in 2000 for eventual display at the SAC, Smithsonian & Air Force museums.
DEF equipment & Digital Recorder
Hull & Bill Whittle de-militarized these for museum displays in 2000
Mission Recording System (MRS)
Collects and records specific internal aircraft flight and sensor activity data on each mission, together with the functioning of airplane and mission systems. Monitors 650 Parameters to include Engine, Electrical, Hydraulic, Digital Automatic Flight and Inlet Control System (DAFICS), Astro Inertial Navigation System (ANS), ECS, MRS and Sensor data
This is the computer MRS readout for the historic New York to London Speed Run in 1974. This document is on display at Smithsonian Air and Space Udvar-Hazy Museum in Washington D.C. and is courtesy of Buz Carpenter (SR-71 Pilot).
(Photo Buz Carpenter)
Film was downloaded from the SR-71 and rushed to the initial processing facility; packaged in canisters and sent to Japan for processing and evaluation as to the take (PI-Photo Interpreters) and then on the the President of the United States for critical decision making criteria.
All film had to be inspected by hand to detect torn or broken film
Color film had to be done in pitch black conditions
Film cut into 500 ft lengths with headers and tails spliced on for processing This insured speedy processing and if there were an accident only a limited amount of film might be effected
Data Link System
Provides near real-time downlink and accelerated dissemination of ASARS, ELINT & Photo data
Sensor Data Transmissions
Go to SR-71 Sensor Web page #1....SR-71 Cameras (Optical)
Go to SR-71 Sensor Web page #2....Radar Imagery
|SR-71 Front Page||Links Page||Index Page||Recollections||2001 Reunion|
|"SR-71 Blackbirds" Web Site Navigator|
|First Created: April 15, 1996 - Last Revised: August 17, 2007|
|Copyright © 1996 Leland R. Haynes Email: email@example.com|
Credits: Mike Hull, Donn A. Byrnes; Russell Harvey, Robbie, David Nolte, Bill Whittle, Jim Fitzgerald, David Dempster, Buz Carpenter, Pima Air Museum, Evergreen Aviation Museum; Don Stein. Tony Landis, Lockheed Martin Corporation
Page #223 of the SR-71 Blackbirds