A Hierarchical Compensation Method for Near Space Target Detection

Abstract

Near space targets have the characteristics of high velocity and high acceleration. High velocity will lead to the velocity ambiguity and range migration (RM). High acceleration will lead to the Doppler frequency migration (DFM) and RM. When the velocity ambiguity number changes many times during coherent integration, the coherent integration gain decreases. In this paper, we propose a hierarchical compensation method. The hierarchical compensation method compensates for the velocity ambiguity number with multiple variations through two-stage ambiguity velocity compensation and frequency domain compensation. Then, the second-order Keystone transform (SKT) compensates for RM and the fractional Fourier transform (FRFT) compensates for DFM. Finally, the simulation experiments prove that the proposed method is effective.