GPS 反射波を利用した海面高度の計測

摘要

This work is intended to develop a Global Positioning System (GPS) receiver specifically designed to process reflected GPS signals off the ocean surface for purpose of ocean altimetry. The goal is to develop a miniaturized GPS sensor allowing for carrying on small platforms, including high-altitude balloons, remote controlled aircraft, and even small satellites flying high above the ocean and capturing the reflected GPS signals during the flight. The prototype receiver consists of only two parts: A pair of GPS RF front-ends provides Intermediate Frequency (IF) digital samples of direct and reflected GPS signals, and a high-speed USB interface that transfers the sampled data to a host PC for post-processing. A preliminary test was performed at the Aioi Bridge over the Sumida River. The RF front-ends were connected to two antennas; one of them pointing to the zenith for direct signal reception, and the other pointing the river surface for collection of the reflected signals. The altimetry results showed that the developed GPS sensor was capable of providing an averaged height error of better than one meter.%本研究では，海面で反射したGPS 信号を利用した海面高度計の実現を目的とし，このような反射波を記録することのできる受信機ハードウェアの開発を行った．