星载微波传感器大气温湿度物理反演算法研究

Atmospheric Temperature and Humidity Profiles Physical Retrieval Algorithm for Satellite-Borne Microwave Sensors

针对我国下一代静止轨道微波探测器资料应用的需求,对微波50~60GHz和183GHz的温湿遥感通道开展了不同大气条件下探测敏感高度的模拟,发现大气散射对微波探测影响明显,尤其是近地面通道,在未来数据应用时需加以注意。提出一种基于一维变分的大气温湿度廓线物理反演算法。以美国最新一代气象卫星Suomi NPP搭载的ATMS(Advanced Technology Microwave Sounder)获取的观测资料为研究对象,RTTOV(Radiative Transfer for TOVS)快速辐射传输模式为前向算子,利用一维变分算法开展了温湿度廓线反演单点试验。研究发现:地表参数对微波亮温,尤其是地面通道影响较大。同时,反演所需背景场对反演结果影响较明显,反演所得温度与背景场较接近。

To facilitate the application of the data from the future microwave instrument,which is planned to be used for China′s next generation geostationary satellite,firstly,the peak altitudes of the weighting functions of 50~60 GHz and 183 GHz microwave channels for monitoring the temperature and humidity are simulated.It is found that atmospheric scattering is of significant impact for these channels,especially near the ground,and this effect should be treated carefully in the future data usage.Secondly,a physical one-dimensional variational(1DVAR)retrieval algorithm is proposed to obtain the atmospheric temperature and humidity profiles.Due to lack of geostationary microwave remote sensing data,in the single point retrieval testing,the data from ATMS(Advanced Technology Microwave Sounder)which is boarded on the USA new generation weather satellite Suomi NPP are used as the testing data,and RTTOV is used as the forward operator.The results show that the surface parameters have an obvious influence on the brightness temperature,in particular for the surface channels.Meanwhile,the retrieved temperature profiles are close to the background field,which indicates the importance of the background in 1DVAR.