Sea signals

 作者:扶城膨     |      日期:2019-03-08 09:01:21
By Jon Copley NOW Global Positioning System (GPS) satellites can not only tell you where you are, they can also give you a weather report for sea areas. This could offer a low-cost alternative to weather buoys and radar satellites for predicting bad weather. GPS signals reflected from the ground are usually considered an annoyance, because they mask genuine signals from the satellites. However, Stephen Katzburg and James Garrison at NASA’s Langley Research Center in Virginia realised that GPS signals reflected from the sea could contain useful information. With a modified receiver, they found they could measure the height of the waves, and the wind speed and direction. Katzburg and his colleagues from the University of Colorado at Boulder presented their results at a remote sensing conference in San Diego last week,