利用GPS接收机反射信号测量水面高度

MEASURING WATER SURFACE HEIGHT BY USING REFLECTED SIGNAL OF GEODETIC-QUALITY GPS RECEIVER

给出一种利用单台测量型GPS接收机反射信号测量水面高度的方法。测量型GPS接收机天线对反射信号和直达信号表现出不同的增益特性,使得反射信号与直达信号在振幅上有明显区别,根据信号振幅与信噪比的关系,建立信噪比与垂直反射距离的函数模型,并利用Lomb-Scargle谱分析方法进行模型解算。两组实测数据的计算结果表明:在良好观测条件下利用反射信号得到的水面高度的标准偏差为±3 cm,在观测条件较差的海面上也能够获得与验潮仪非常一致的结果。

A water quality receiver is develo surface height measurement method using reflected signal collected by a single geodetic- ped. Signal-to-noise ratio （SNR） is derived from the carrier tracking loop outputs and is the sum of the direct and reflected amplitude, as reflected amplitude is much smaller than the direct amplitude due to receiving antenna gain pattern effects and indirect signal attenuation upon reflection, then the reflected signal amplitude can be separated from the SNR data. Finally, a time-variying model which describes the functional rela- tionship between the reflected signal amplitude and the height of reflector is derived, and Lomb-Scargle periodogram is used to solve the model. Two experiments have been conducted under different conditions. The sea surface height derived by GPS reflected signal show excellent agreement with tide gauge measurements.