y SR-71 Sensors Page #3

Electronic Intelligence (ELINT & SIGINT)

Precise characteristics and locations of Emitter Signals

Signal Intelligence (SIGINT)

The 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 ELINT (EMR) System as well as other collection assets prepositioned in the area at the time. The enemy's capabilities and frequency's used for each radar or missile site were then documented revealing the enemy's battle plan. The SR-71 had over 1,000 missiles fired at it over the course of it's active duty without a single loss of aircraft.

EMR System


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

DEF "A2C" System and the DEF "C" System (Right grey vertical Unit) Manufacture: ITT

DEF "A2C" System was only used during the reactivation period of the program from 1994-2000

DEF "H" System

AR1700 DEF and ELINT Recorder

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.

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 64 Parameters to include Engine, Electrical, Hydraulic, Digital Automatic Flight and Inlet Control System (DAFICS), Astro Inertial Navigation System (ANS), ECS, MRS and Sensor data

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

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First Created: April 15, 1996 - Last Revised: August 17, 2007
Copyright © 1996 Leland R. Haynes     Email: sr71webmaster@sr71.us

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