In bistatic spaceborne High-Resolution Wide-Swath SAR systems (HRWS-SAR), the azimuth reconstruction to obtain a uniform sampling signal or Doppler spectrum is a crucial step in image processing because azimuth signals are generally of non-uniform sampling type. In this study, the variant transmitting distance to receiving distance radio is approximated to be a constant, the equivalence between the bistatic and monostatic SAR azimuth interchannel transfer functions is deduced, and the azimuth signal model in spaceborne HRWS-SAR with general bistatic configuration is established. Furthermore, the matrix inversion algorithm to reconstruct the azimuth signal is proposed; in addition, to measure the reconstruction performance, the formulae for the signal noise ratio scaling factor and the azimuth ambiguity signal ratio are provided. The azimuth reconstruction is simulated in several spaceborne HRWS-SAR systems with typical bistatic configuration, and the results show that the azimuth Doppler spectrum can be correctly reconstructed via the matrix inversion algorithm when the azimuth sampling is conducted without coinciding samples.

有源压制干扰从雷达天线的主瓣进入雷达内部,干扰信号很强时,将严重影响雷达的检测性能.传统的旁瓣消隐、旁瓣相消以及低副瓣天线等技术难以奏效.文中分析了盲源分离技术应用雷达主瓣抗干扰时盲源分离的信号存在幅度、相位的不确定性,提出了一种联合盲源分离和分数阶傅里叶变换的雷达抗主瓣干扰的新方法.并给出新方法与传统脉冲压缩方法主瓣干扰抑制的仿真结果,仿真结果表明了在强噪声压制干扰环境中,新方法具有良好的抗主瓣干扰的性能.

For distributed aperture coherent radar of general signal processing architecture, the estimating performance of time delay differences and phase differences, and the output Signal to Noise Ratio gain (oSNRg) based on cross-correlation are studied in this paper. Firstly, the signal models are proposed in Multiple-Input Multiple-Output (MIMO) mode and Fully Coherent (FC) mode respectively. Then the phase ambiguity with estimating phase differences by cross-correlation is deeply analyzed, and an effective method for resolving ambiguity is proposed to estimate robustly the phase differences. Numerical examples demonstrate that when the input SNR is high enough, the coherence parameters can be estimated robustly and the oSNRg approaches the ideal value by cross-correlation method.

在扩展目标条件假设下,提出了一种联合优化发射端和接收端资源配置的认知雷达序贯信号检测方法.该方法在假设检验的基础上,根据系统之前时刻获得的目标先验信息在发射端进行自适应波形设计,在接收端进行自适应检测门限值调整,以提高系统的检测性能.理论分析和仿真实验表明:通过收-发联合优化处理后,系统的估计性能和检测性能都得到明显提高.同时,随着循环次数的增加,目标冲激响应的估计精度越来越高,使得发射波形也越来越逼近最优波形,估计检测概率和虚警概率也越来越逼近各自的真实值,从而在提高系统性能的同时也保证了决策的可靠性.