GNSS-R海洋遥感原始数据采集系统研究与实现

A raw data acquisition system for detecting ocean wind-fields

利用全球导航卫星系统反射信号(GNSS-R)实现海面风场探测,是一种新型的微波遥感技术.获得表征海面粗糙度等信息的原始数据是实现导航卫星反射信号对海面风场探测的关键技术之一,对导航卫星反射信号软件接收机的研究,其原始数据获取更为重要.该文在分析GPS海面风场探测前向散射机理基础上,结合GPS直射信号接收理论,设计完成了基于FPGA实现的双射频前端海洋遥感原始数据采集系统;阐述了系统组成原理及关键模块设计过程,给出了机载试验及试验数据分析结果;得到卫星直射信号和对应反射信号镜面反射点路径延迟的试验结果与理论计算值基本一致,误差为0.28%,能正确表征镜面反射点等海面粗糙度信息,试验结果符合海洋遥感参数反演的精度要求.

A new microwave remote sensing technology has been developed for detection of ocean wind-fields based on global navigation satellite system reflectometry （GNSS-R）. Getting raw GNSS-R data that describes sea surface roughness was one of the key needs in the field of ocean wind-field detection. For this, it was necessary to study and exploit the software receiver that processes the GNSS-R signals. Theories for forward-scatter and for GPS direct signal receivers were analyzed ; the design of a double RF front-end raw data acquisition system based on field-programmable gate arrays （FPGA） was then implemented. Working principles and design processes of key modules were developed; airborne experiments and data processing were conducted. The results were basically consistent with teat data and theoretical analysis about the speeular reflection eaele delay of direcd transmissions reflected signals. Errors were 0.28%, and the information on sea surface roughness can be described. Test resultg meet parameter precision requirements for oceanic remote sensing.