Water Level Changes Measurement of Reservoir Using Multi-GNSS Reflectometry

Water level change is the crucial disastrous factor of reservoir deformation. This paper derives the water level changes of reservoir based on GNSS-R technology by using the multi-GNSS deformation monitoring observation data of Xikeng dam in Shenzhen, and compares the results with the artificial observation data. The numerical results show that the root mean square error (RMS) of GPS-R results is 7 cm with the accuracy of BDS-R and GLONASS-R is slightly lower than GPS-R, and the range of RMS is 8-10 cm. However, the changes are consistent with the artificial observation data, and the correlation coefficients between the experimental results of three system and the artificial observation data are better than 0.9. This research verifies the validity and reliability of GNSS-R technology used to water level changes measurement, and expands the application areas of the GNSS deformation monitoring system, which also indicates that multi-GNSS system can greatly improve the temporal resolution of single-system water level measurement.