Clutter mitigation by null constraint coherent integration under various conditions

In this paper, the null constraint coherent integration (NCCI) technique is proposed and validated its performance under various clutter conditions. The usable Doppler space fraction (UDSF) and minimum detectable Doppler frequency (MDDF) is mainly used for the validation when received clutter has different Doppler spectrum with the one used for the designing the projection matrix for the NCCI. By numerical simulation, it is observed that UDSF and MDDF of the NCCI is not affected by the received stationary clutter with different clutter bandwidth in the design range and kept its superiority over the conventional MTI plus FFT. For the received clutter with different center frequency, performance of the NCCI is hardly affected up to 0.01 of the normalized center frequency.