基于观测量校正的星载GNSS-R海面风速快速反演方法

A fast spaceborne GNSS-R sea surface wind speed retrieval method based on observation correction

快速反演(FDI)算法是一种典型的星载全球卫星导航反射技术(GNSS-R)海面风速反演方法,具有计算复杂度低、快速实时反演的特点,但是FDI算法中的反演观测量提取精度不高,导致风速反演精度低.针对于此,提出基于观测量校正的改进FDI算法,用于实现海面风速的快速高精度反演.该方法首先利用辅助测量信息对观测量进行校正以降低干扰因素的影响,然后基于统计分析方法对ASCAT卫星风速数据进行海面风速值提取,最后建立了海面风速与校正观测量的地球物理模型函数(GMF)关系式,实现对海面风速的反演.与传统FDI算法相比,该方法的反演偏差值更小,均方根误差(RMSE)降低了29%.

The fast-delivery inversion(FDI)algorithm is a typical spaceborne Global Navigation Satellite system Reflectometry(GNSS-R)sea surface wind speed inversion method,which has the characteristics of low computational complexity and fast processing.However,the retrieval observation extraction accuracy in FDI algorithm is low,which leads to low wind speed retrieval accuracy.In view of this,an improved FDI algorithm based on observation correction is proposed to realize the fast and high-precision retrieval of sea surface wind speed.In this method,firstly,the auxiliary measurement information is used to correct the observation to reduce the influence of interference factors,then the sea surface wind speed value is extracted from the ASCAT satellite wind speed data based on the statistical analysis method,and finally the geophysical model function(GMF)relationship between the sea surface wind speed and the corrected observation is established to realize the retrieval of sea surface wind speed.Compared with the traditional FDI algorithm,the wind speed retrieval bias of this method is smaller,and the root-mean-square error(RMSE)is reduced by 29%.