逆合成孔径雷达多普勒质心跟踪法性能分析

Performance Analysis of Doppler Centroid Tracking for ISAR Autofocusing

目标强散射中心的转动相位成分(RPC)是限制逆合成孔径雷达多普勒质心跟踪(DCT)法自聚焦性能的主要因素.基于统一的目标散射信号模型,本文提出扰动角的概念以衡量RPC的影响,并分析了决定扰动角的若干因素.据此,本文证明了提高雷达脉冲重复频率可改善DCT法的自聚焦性能,并证明了圆移位DCT(CS-DCT)和图像均衡DCT(IE-DCT)两类改进方法的原理等效性.最后,数值实验结果验证了本文性能分析的正确性.

The rotational phase component （RPC） of target＇s prominent scattering centers may affect the performance of Doppler centroid tracking （DCT） seriously in the inverse synthetic aperture radar （ISAR） autofocusing. Based on a unified ISAR scattering signal model, this paper introduces the concept of induced angle to evaluate the effect of RPC, and the factors affecting the induced angle are also analyzed. It is proved that the performance of DCT may be improved with the increase of radar pulse repetition frequency,and it is also shown that two improved DCT methods,i.e, circular shifting based DCT （CS-DCT） and image equilibrium based DCT （IE-DCF） are equivalent in principle.At last,numerical experiments are also provided to verify the effectiveness of the above performance analysis.