机载三通道SAR/GMTI性能分析及改进方法

Performance analysis and improved method for airborne three-channel SAR/GMTI system

在分析经典的三通道SAR(Synthetic Aperture Radar)地面动目标指示(GM-TI,Ground Moving Target Indication)方法原理的基础上,提出一种较全面三通道SAR/GMTI性能评价方法.该方法同时考虑了载机存在速度误差、通道不匹配、杂波内部运动和系统噪声等主要误差因素,并分析了各种因素对系统性能的影响.经典的三通道SAR/GMTI方法存在的缺点是不能同时提高最大不模糊可检测速度、最小可检测速度和盲速指标的性能以满足系统设计的要求.给出了一种新的天线布置方案和动目标检测方法,改进的检测方法在不增加通道数的前提下,较好地解决了该问题,具有很好的实用性.最后通过计算机仿真验证了新方法的可行性.

A comprehensive performance analysis method of three-channel SAR（ synthetic aperture radar） GMTI （ ground moving target indication） was presented after analyzing the theory of conventional three channel SAR ground moving target indication methods. The main error factors such as velocity variety of radar platform, receiver channel mismatch, clutter internal motion and system noise were considered in this method and the detection performance of each error factor affect on was analyzed too. The shortcoming of conventional three channel SAR/GMTI methods is that the performance of minimum detectable velocity, ambiguous speed and blind-speed simultaneously can＇t be improved to meet the requirements of the system. The improved method solves the problem without increasing receiving channels by rearranging the transmitting and receiving antennae. Theoretical analysis and simulation results show the validity of this scheme.