Low-angle Estimation Based on Multi-frequency Maximum Likelihood

Abstract

Amony various low-angle estimation methods, MUSIC method and Maximum Likelihood(ML) Method are representative, but the classical MUSIC method can not directly process coherent signal and need spatial smoothing techinique to decorrelate the coherence of the direct and reflected echo, which would reduce spatial resolution ratio.In order to deal with this problem, a new estimation method using multi-frequency signal for low-angle targets is proposed in this paper.First sequential transmission several different frequencies in pulse-to-pulse is applied to decorrelate the coherence of the direct and reflected echo, then the Alternating Projection(AP) Method is combined with Maximum Likelihood Method to simplify the numeration.Finally, the simulation results show that the algorithm can improve the estimation performance of low-angle radar.