SOLDIER IDENTIFICATION SYSTEM UTILIZING LOW PROBABILITY OF INTERCEPT (LPI) TECHNIQUES

This paper documents the design of a laser/radio frequency (RF) Soldie r Identification (ID) System developed by Dynetics, Inc., Harris, Corp ., and the US Army Communications and Electronics Command (CECOM). The Soldier ID system includes an Interrogation Unit with a programmable activation code. The Interrogation Unit consists of a directive, eye-s afe laser and a spread-spectrum RF transceiver. This allows for a low probability of intercept (LPI) interrogation, which is of interest dur ing covert operations. A Responder Unit is worn, for example, by a sol dier and transmits an LPI spread-spectrum RF response, only after rece iving the proper interrogation codes. The basic subsystems for the ide ntification system are a Laser Interrogation Unit, an RF Responder Uni t, and an electronic Programming Unit. The operating principles for th e subsystem are reviewed, and the design issues are discussed, In addi tion to the preliminary design performed under Phase I of the program, a breadboard system was developed to validate the proof-of-principle concept, Hardware implementation is reviewed and test results are pres ented. The brassboard development and engineering plans are also prese nted.