机构地区: 北京航空航天大学电子信息工程学院
出 处: 《信号处理》 2007年第1期31-35,共5页
摘 要: 匹配滤波与解调频脉压是合成孔径雷达中常用的两种处理方法,理论上这两种方法在获得的信噪比和分辨能力上是相同的,但实际应用中却存在差异。本文首先从理论上分析了当回波存在多普勒偏移以及调频率存在误差时,这两种压缩方法对测距精度与距离分辨率产生的影响。接着重点讨论了两种压缩方法的抗噪声性能,在假设同波中存在白噪声时,对输出结果的信噪比进行了分析。理论分析和仿真结果表明,匹配滤波方法比解调频方法的抗噪性更好,解调频方法的抗干扰能力低于匹配滤波方法。本文结论对SAR系统的设计具有一定的参考价值。 Matched filtering and dechirp processing are the common methods in SAR. In theory,the two methods obtain the same SNR and resolution, but they are different in practical application. The performance of the matched filtering and dechirp processing that use in common for SAR echoes in range, were studied in details in this paper. Firstly, the effects on range precision and range-resolution of the two methods are compared in the conditions that radar echoes have a Doppler shift and the error of the chirp rates exist,respective- ly. Then the antinoise characteristic of the two methods were discussed. The effects of white noise on the SNR through these two methods were analysised. The theoretical analysis and computer simulated results demonstrate that the advantages of matched filtering over dechirp processing in the antinoise characteristic. The conclusions of this paper have some valuable reference to the SAR system design.