A New Retrieval Method of Significant Wave Height Based on Statistics of Scattered BeiDou GEO Signals

GNSS-R (Global Navigation Satellite System-Reflectometry) is a new tool to observe significant wave height (SWH). So far, the following two approaches have been considered. One is Interferometric Complex Field (ICF) and the other is Interference Pattern Technique (ITP). The stable geometry of BeiDou GEO satellite can avoid the modulation of measurement by the antenna radiation pattern and elevation angle with the satellites moving for coastal GNSS-R. Therefore, the statistics of measurements are only related to the sea state. In this paper, Weibull distribution of normalized waveform of scattered BeiDou GEO signals is found through analyzing the experimental data. From this perspective, a new retrieval SWH method based on the expected values of normalized waveform is presented. Finally, results from comparing the retrieved SWH and the in-situ SWH measured by nearby Buoy show good agreement with average deviation of -0.06m, root-mean-square of 0.26m and correlation coefficient of 0.93.