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.