Coherent integration for maneuvering target detection via fast nonparametric estimation method

Abstract

Maneuvering target presents a great threat for radar detection applications. The complex unknown motions between radar and maneuvering target seriously affect the performance of target coherent integration. Existing methods utilizing parameter search or estimation are limited by the high computational burden and the propagation errors of different parameter estimations. In this study, a fast nonparametric estimation method is proposed for coherent integration of maneuvering target. Firstly, the second-order Keystone transform is adopted to eliminate the quadratic range cell migration (RCM). Secondly, the modified range frequency reversal process is proposed to simultaneously remove the complex low- and high-order Doppler frequency broadenings (DFBs) by a one-step matrix multiplication operation. Subsequently, the residual RCM is corrected by the proposed improved time-scaled transform without searching for the Doppler ambiguity number, and then a well-focused result can be obtained. The proposed method is simple to implement and computationally efficient given that searching and estimation of parameters are avoided. It also addresses the high-order DFB and blind speed sidelobe. The processing results of simulated and real data are presented to verify the performance of the presented approach.