Recursive filtering Radon-ambiguity transform algorithm for multi-LFM signals detection

In the multi-LFM (linear frequency modulation) signals condition, the Radon-ambiguity transform (RAT) of the strong LFM component has a strong suppression effect on the weaker LFM components. A recursive filtering Radon-ambiguity transform (RFRAT) algorithm is proposed to solve this problem. In this method, we make full use of the character of the maximum likelihood (ML) estimation of the frequency rate obtained by the Radon-ambiguity transform and eliminate the strong component step by step by an adaptive dechirp filtering algorithm. The validity of this method is shown by computer simulation even in the low signal to noise ratio (SNR) condition.