A Doppler Ambiguity Tolerated Method for Radar Sensor Maneuvering Target Focusing and Detection

Abstract

Maneuvering target detection is a challenging task for modern radar sensor applications. Range migration (RM) and Doppler frequency migration (DFM) lead to serious coherent integration loss, which affects the performance of maneuvering target focusing and detection. Moreover, Doppler ambiguity can easily appear due to the limitation of pulse repetition frequency; thus, maneuvering targets become difficult to focus correctly. In this paper, a new Doppler ambiguity tolerated method is proposed to focus and detect maneuvering targets with jerk motions. First, the order of RM and DFM is reduced by multiplying the signals before and after the time reversal operation. Second, generalized modified keystone transform is proposed to eliminate residual RM and DFM simultaneously. Subsequently, a well-focused result is obtained. In comparison with the traditional keystone transform (KT) or second-order KT based methods, the proposed method works well in situations wherein Doppler center blur and spectrum ambiguity appear. Moreover, the computational complexity of the proposed method is remarkably reduced in comparison with that of multidimensional parameter searching methods. These advantages show that the proposed method achieves balance between detection performance and computational load. The experiment results validate the effectiveness of the proposed method.