基于GPS遥感的延迟映射接收机关键技术

全球卫星定位系统GPS(Global Positioning System)广泛应用于定位和导航,还可利用海面对GPS信号产生的散射效应进行微波遥感,是一种新型微波遥感手段.首先介绍了GPS海洋遥感测风技术产生背景及特点,给出了GPS散射信号测量技术理论基础,重点分析了延迟映射接收机设计中提高采样信号信噪比、双射频前端电路设计、计算反射点延迟、接收机工作模式、内嵌软件处理等5项关键技术.设计的延迟映射接收机样机在天津近海完成了首次搭载飞行试验,试验结果表明,延迟映射接收机可同时接收直射和海面散射卫星信号并输出导航定位解,正确计算镜面散射点码延迟,准确接收海面散射的GPS卫星信号,且散射信号信噪比达到了14.9?dB以上,接收机输出为反演海面风场提供了准确的基础数据,这种方式可推广到遥感探测陆地土壤湿度、海冰厚度、海浪高度等领域.

Design of delay mapping receiver for GPS remote sensing

Signals of global positioning system (GPS) can be used for purposes such as navigation and positioning. The utility of scattered GPS signals from rough surfaces brings a new technology for microware remote sensing. Background and advantage of GPS based sea surface wind remote sensing technique and scattered GPS signal measurement technique was introduced. Five main techniques were discussed such as improving the signal noise ratio, dual radio frequency front-end circuit design, calculating the specular point code delay, receiver work mode and the embedded firmware process. Data collection campaigns were done at Tianjin near sea with the receiver mounted on an airplane. Results show that the receiver can simultaneously receive direct and ocean scattered GPS signal, correctly calculate specular point delay, successfully measure the ocean scattered signals correlation power around the specular point, and signal noise ratio is higher than 14.9?dB. Receiver outputs provide basic data sets for ocean wind retrieval. The technique can also be used in land moist sensing, sea ice age sensing, ocean wave height remote sensing.