毫米波测云雷达二次回波的回扩识别和距离旁瓣研究

毫米波测云雷达是一种重要的云遥感探测手段。为了获得大功率探测能力,本文所用云雷达使用了脉冲压缩技术和双脉冲技术,但也因此会出现二次假回波和距离旁瓣假回波。本文研究了假回波对云雨探测的负面影响,分析了产生二次回波的原理,设计了区域回扩法结合余弦相似度计算的二次回波定量识别算法。个例分析表明算法有较好的识别能力。本文还为定性判断距离旁瓣影响提供了一种简便可行的途径。研究结果可用于改善毫米波雷达的资料质量。

Back expansion recognition of second-trip echo and range sidelobe research with millimeter wave cloud radar

Millimeter-wave cloud radar is an important means of cloud remote sensing. In order to obtain high power detection capability, the radar used in this paper utilizes pulse compression and double-pulse technology which may lead to second-trip and range side lobe fake echoes. In this paper, the negative effects of fake echoes on measurements of cloud/rain are studied. The principle of second-trip echo generation is analyzed, and a secondary echo recognition algorithm is designed based on the combination of area back expansion and cosine similarity calculation. Case studies demonstrate that the algorithm has a strong recognition ability. The paper also provides a simple and feasible way to qualitatively judge the influence of distance side lobe. The results of the study can be used to improve the quality of data in millimeter-wave radars.