Beamspace time-frequency MUSIC with application to airborne antenna arrays

We introduce the beamspace time-frequency (t-f) MUSIC as a hybrid scheme which combines the advantages of beamspace processing and time-frequency distributions for high resolution directional finding of signals with time-varying characteristics. The proposed beamspace t-f MUSIC performs high resolution angle-of-arrival estimation using the time-frequency signatures of the outputs of the beams, rather than the sensor data, as previously proposed. Two beamspace t-f MUSIC techniques are presented, one is based on joint block-diagonalization of multiple t-f points whereas the other is based on averaging over t-f regions prior to subspace estimation. Both techniques utilize the power distribution of the signal arrivals within different beams over both time and frequency.