基于北斗/GNSS-R的厘米级水位测量

Centimeter-level water level measurement using BeiDou/GNSS-R

水位变化监测是防洪抗旱的重点工作之一,全球导航卫星系统反射测量(Global Navigation Satellite System-Reflectome‐try,GNSS-R)技术已被证明可进行高精度、全天候、全天时的水位变化监测。我国北斗卫星导航系统(Beidou Navigation Satellite System,BDS)拥有丰富的频段数据,在GNSS-R遥感应用领域中具有广阔的应用前景。基于湖南省浏阳河流域建设的GNSS-R实验观测站数据,进一步研究了BDS在水位反演中的性能,分别采用频谱分析法和非线性拟合法对站点水位变化进行测量,并将实验结果与附近水文站的实测数据进行对比分析。结果表明,非线性拟合法相较于频谱分析法,水位测量精度大幅提升,均方根误差(RMSE)平均降低了66%,且多频数据融合后RMSE达到了1.8 cm,整体上BDS的水位反演性能与GPS相当。

Water level monitoring is one of the key tasks in flood control and drought resistance.Global Navigation Satellite System-Reflectometry(GNSS-R)remote sensing technology has been proven to be capable of high-precision,all-weather,and all-day monitoring of water level changes.China's BeiDou Navigation Satellite System(BDS)has rich frequency band data and has broad application prospects in the field of GNSS-R remote sensing.Based on the GNSS-R experimental station built in the Liuyang River Basin,this paper further studies the performance of BDS in water level inversion.The spectrum analysis and nonlinear fitting methods are used to measure the water level changes of the station,and the experimental results are compared and analyzed with the measured data of the nearby hydrological station.The results show that the nonlinear fitting method has a significantly improved accuracy compared with the spectrum analysis method,with an average RMSE reduction of 66%.After the fusion of multi-frequency GNSS data,the RMSE reaches 1.8 cm.Overall,the water level inversion performance of BDS is comparable to that of GPS.