Abstract:

A direct data domain (DDD) approach with iterative space-time adaptive processing (STAP) is proposed to deal with the problem that performance of clutter suppression for airborne radars abtained by conventional STAP methods degrades in a heterogeneous clutter environment. Firstly, a new iterative adaptive approach (IAA) for estimation of the spatial temporal spectrum is introduced according to the special structure of the received data and the sparsity of the spatial-temporal spectrum. Then, the aperture lossless covariance matrix for the cell under test is constructed by the estimated spatial-temporal spectrum. Finally, a new covariance matrix regularization method is presented to prevent signal cancelation according to the distribution of the target in the spatial-temporal plain. Numerical examples are given to show that there are about 10dB and 5dB signal to clutter plus noise ratio improvement in the sidelobe clutter region relative to the direct data domain approach and the Doppler wrapping method respectively, even in the presence of 3% array error.