Power waveforms analysis for sea state determination using Beidou MEO satellite delay signals

In this paper, remote sensing of global navigation satellite system (GNSS) is proposed for determination of sea state condition. The approach is already proved as an effective tool for measurement of sea state, especially for sea wind estimation, sea wave height measurement, sea roughness measurement and so on. Firstly, this technique is utilized to generate the power waveforms of GNSS-R delay signals from Beidou MEO satellite. Secondly, these waveforms are analyzed to retrieve information from sea surface. Two models are used to generate power waveforms from Beidou MEO satellite reflected signals. The wave spectrum model is used to find sea surface up and cross variances. The Z-V scattering model is used to generate power waveforms using the outputs of the wave spectrum model. The generated power waveforms are analyzed with three parameters, i.e. coherent integration time, wind speed & satellite elevation angle. From the analysis, it's observed that amplitude and shape of these power waveforms are clearly different for different situations of sea surface. It indicates that there is a sharp relationship between amplitude of the waveforms and sea surface state conditions. This relation is used to determine the sea state determination. The obtained result of sea state is compared to real surface situation i.e. wind speed & sea wave height which are collected from data campaign site. It is found that the determined sea states are closely matched with real situations of sea surface.