地基和星载微波辐射计数据反演大气湿度

Humidity retrieved from data of the ground-based microwave profiler and satellite-based humidity sounder

分析了地基和星载微波辐射计设计指标和探测特点。利用大气辐射传输理论和毫米波传播模型,1993(MPM93)和大气吸收系数模型,建立大气正演辐射传输模型。仿真风云三号A星(FY-3A)星载微波湿度计和地基探测仪的亮温数据,误差在允许范围内。对比星载和地基微波辐射计不同高度反演精度和均方差,建立基于3层神经网络算法的联合地基和星载观测数据的反演模型,改善现有反演精度。选取2008年1-12月晴天探空数据,试验结果表明:改进的反演模型在所研究的高度范围内具有更好的反演精度,反演的大气水汽密度廓线较单独利用星载或地基微波辐射计更接近真实值。

Analysis of the system specifications and sounding characteristics of ground-based and satellite-based microwave radiometer is described. Based on the principle of atmospheric radiative transfer, millimeter-wave propagation model 1993 （MPM93） and atmospheric absorption model, a forward atmospheric radiative transfer model is presented with acceptable error. The calculated brightness temperatures are better agreed with the measurements of microwave humidity sounder （MWHS） and ground-based atmospheric microwave profiler. Through the compari- son of microwave radiometer in different sounding types, the paper constructs an improved neural network combining satellite-based and ground-based observations. For the data from January to December in 2008, the experimental results show that in the whole altitude（0-10 km）, the improved retrieval model has high resolution with smaller root mean square error （RMS）, and the retrieval water vapor profiles agree more with radiosonde datasets.