Multiple target detection through DFT processing in a sequential mode operation of real two-dimensional arrays

A technique for multiple target detection through discrete Fourier transform (DFT) processing of information collected by a phase array operating in the sequential mode was presented for linear arrays by Polge et al. (1989). The DFT processing in the sequential mode is extended to 2-D arrays. This technique allows simultaneous detection of all targets within the 3-dB beam of a single element. The system resolution is limited by that provided by the 2-D fast Fourier transform (FFT). After forming the 2-D information sequence, the processing of the information sequence becomes a problem of a 2-D power spectral analysis. However, correction for antenna gain and range attenuation is needed. Frequency interpolation helps reduce the peak variation in the amplitude spectrum. The technique was simulated and validated through computer simulation. An example shows that all the targets are detected at the correct azimuth and elevation and with the proper strength