Abstract

A compact beacon-detector type IFF system to be carried by individual soldiers. The system consists of a beacon and a special purpose detector. The beacon is a small, light-weight, battery powered device that is worn on the soldier's web gear. The detector consists of a small flashlight-like device that can be hand held or mounted on a weapon, similar to a rifle scope. The beacon's signal is not visible to those using existing night vision equipment nor is it otherwise exploitable by a potential adversary. The system achieves its covertness through the selection of the optical wavelength used by the beacon. Further signature reduction is achieved through the use of a Low Probability of Intercept ("LPI") spread spectrum waveform as the beacon output. This waveform utilizes a spreading code to encode the beacon output signal. Even if an enemy has a sensor capable of detecting the proper optical wavelength, it would not be able to detect or emulate the beacon's signal without prior knowledge of the specific spreading code used. The detector of the present invention is designed to despread the beacon output waveform, allowing the signal to be detected. This spread/despread code can be changed as frequently as required, so that capture of the beacon or detector would not be a serious risk to compromising the system.

Other References

• Curtis, Nonimaging Identification Structure, Sep. 1, 1987, Statutory Invention Registration No. H33