Extension of adaptive angle doppler compensation (AADC) to increase homogeneity of secondary data in bistatic airborne radar

Main problem for airborne radars in detecting of ground targets is clutter. Space-Time Adaptive Processing is newest method to confront of this signal. A two-dimensional filter puts zeros in Doppler and spatial frequencies related to spectrum of clutter. In calculating of weight vector، covariance matrix of interference signal plays an important role. In practice this matrix is unknown and must be estimated. In this paper adaptive angle-doppler compensation method (AADC) in Bistatic airborne radar is extended to achieve higher SNR in output. In this method compensation in spatial and temporal frequencies is repeated in several stages to increase homogeneity of secondary data used in estimation of covariance matrix. In this new approach subspaces related to clutter covariance matrix decomposition for secondary data are aligned with subspaces of covariance matrix in test range-gate. Simulations in MATLAB shows 3 dB improvement for new approach in comparison to conventional AADC for a spacial scenario