A SYSTEM FOR LOCATING AND DISTINGUISHING TARGETS

摘要

A system for simultaneously locating a plurality of targets and distinguishing the targets from noise which utilizes phase detector techniques to generate complex voltage signals and obtain phase information. Spectral analysis is performed on the complex voltage temporal functions to generate doppler frequency functions. Both spectral phase functions and spectral amplitude functions are generated from the doppler frequency functions. Spectral phase functions are analyzed using interferometry techniques to determine if a potential target has a common locational source from returns of a plurality of sensors. A zenith angle is also generated using interferometry techniques to provide locational information of the multiple targets. Range gating and two frequency range detection methods provide high resolution range information as to the location of the targets. High resolution range information and two dimensional zenith angle information are used to provide an image of the targets. The present invention uses a two-frequency pulse which can be generated simultaneously or sequenced within a pulse in a manner which is phase coherent. The two-frequency pulse eliminates problems associated with range aliasing, zenith angle aliasing, scattering point analysis and allows for range location with high resolution. An error correction factor is also generated which eliminates spectral smearing.