Research on Sea Surface Height Measurement Based on GNSS-IR Dual Frequency Data Fusion

摘要

It is an important application of GNSS in marine remote sensing to measure sea level by using Global Navigation Satellite System Interferometry Reflectometry (GNSS-IR), which provides a new direction for global sea level change research. At present, the accuracy of sea level retrieved from GNSS single-frequency observations needs to be further improved. In order to solve this problem, this paper proposed a new retrieval method based on the peak weighting scheme of integrating the respective sea level retrieved from signal-to-noise ratio (SNR) data of two single frequency L1 and L2 of the Global Positioning System (GPS). The peak weighting method takes the peak power of the spectral analysis of the observed signal-to-noise ratio as the weight, thereby integrating dual-frequency data for sea level retrieval. In order to verify the validity of the mentioned method, the continuous multi-day dual-frequency SNR observation data of two coastal GPS stations were processed and analyzed. At first, the Lomb-Scargle Periodogram (LSP) spectral analysis method was used to obtain the peak oscillation frequency. Then the peak weighting method is used to fuse the two-frequency sea level retrieval results. At last, the sea level results obtained from the single-frequency observations are compared with that of the double-frequency observations, and the proposed weighting method is verified by comparing with tide gauge. The results show that the accuracy of the retrieval results using the peak weighting method is better than that of the GPS single-frequency observations when sea condition is good, while the accuracy improvement is not obvious when the sea surface is rough.