The development of multi-processor software, for the demonstration of passive real time threat emitter location

A software development which supports the demonstration of an alternative, and much faster, method of measuring emitter range is described. This IR&D program, called DFLS (Direction Finding and Location System), combines interferometry with precision angle rate measurement to estimate range. The program has extended over several years beginning in 1989 with the development of an interferometry antenna array. In 1990 the antenna was incorporated into a receiver system and interfaced with an HP-300 computer for ground tests. Using the software described herein it was possible to estimate the range of a moving emitter within 5% in from 3 to 20 s (depending on initial angle). In 1991 the hardware and software were upgraded to be able to obtain measurements from an airborne platform. The software was completed and fully tested in 1991