Source identification system for closely separated spatial sources

Claim 1

A source identification system which identifies and displays remote sources comprising: a) a plurality of M receive branches each having i. a phased array sensor for receiving a signal from said sources at a time index l, ii. a demodulator responsive to the phased array sensor for demodulating the received signal from the sensor, iii. an analog-to-digital (A/D) converter responsive to the demodulator for converting the demodulated signal to a digital value x l (n) at specific time periods indicated by a time index l, and n is an index for the phased array sensor which received the signal; b) a snapshot storage unit responsive to the receive branches for collecting a plurality of N snapshots with the digital values organized in a matrix format X N , each snapshot being all the digital values x l (n) from the receive branches at a time represented by time index l; c) covariance generation unit responsive to the snapshot storage unit for calculating a set of sample covariance values R N from digital values x l (n) for the plurality of snapshots organized in the matrix format X N ; d) eigenanalysis processor responsive to the covariance generation unit for creating a set of eigenvalues and eigenvectors λ k e k from the sample covariance values R N ; f) a source number estimator responsive to the eigenanalysis processor for determining a number of sources d from the set of eigenvalues and eigenvectors λ k e k ; g) direction of arrival (DOA) processor responsive to the eigenanalysis processor and the source number estimator for determining a set of manifold vectors a(θ i ) indicating the direction of arrival θ i of said remote sources from number of sources d and the set of eigenvalues and eigenvectors λ k e k ; h) power estimation processor responsive to the eigenanalysis processor and the DOA processor for creating a set of signal to noise estimates for each of said remote sources; i) target detection logic unit responsive to the power estimation processor and the DOA processor for identifying sources of interest to monitor based upon analyzing the source array manifold vectors a(θ i ), and signal to noise ratio (SNR) estimate ##EQU11## j) a signal synthesis and decoding unit for decoding the identified signals and synthesizes a display signal; and k) an output device for creating an image representing the identified sources from the synthesized display signal.