基于仿真的6.9 GHz通道亮温改进FY-3D MWRI海面温度产品

海洋表面温度SST（Sea Surface Temperature）是全球海洋和气候研究的重要参数之一，卫星被动微波遥感由于能够实现全天候观测而被越来越多的应用到SST研究中。中国的风云三号（FY 3）卫星搭载的微波成像仪（MWRI）缺少对SST更加敏感的7 GHz附近垂直极化通道，本研究将FY 3 MWRI与具有6.9 GHz通道的Aqua AMSR 2进行时空匹配，采用神经网络方法，利用匹配的FY 3 MWRI的通道亮温模拟仿真AMSR 2的69 GHz垂直极化通道亮温（6.9V），通过引入仿真的6.9V来提高FY 3 MWRI SST的反演精度。结果表明：引入仿真的6.9V可以改进FY 3 MWRI SST反演精度，对35°～90°S之间海域的SST改进更加显著，主要由于6.9V对低SST的探测灵敏度更高且在低SST反演时受风速的影响较小导致的。如果FY3后续卫星可以搭载6.9 GHz通道，将可进一步提升低SST特别是两极SST的反演精度。

Improving the FY-3D MWRI Sea Surface Temperature Based on Simulated 6.9 GHz Brightness Temperature

SST (Sea Surface Temperature) is one of the most important parameters in the global ocean and climate research. Satellite passive microwave remote sensing is used more and more in SST research to realize all weather observation. The Microwave Imager (MWRI) on the FY 3 satellite lacks the 7GHz vertical polarization channel, which is more sensitive to SST. In this study, FY 3 MWRI and AQUA AMSR 2 are spatiotemporally matched, and the neural network method is used to simulate the 6.9 GHz vertical polarization brightness temperature (6.9V) of AMSR 2 using the matched MWRI channel brightness temperature. The simulated 6.9V is introduced to the inversion of FY3 MWRI SST. The results show that: After introducing the simulated 6.9V, the inversion accuracy of SST is improved, and the improvement in 35°-90°S is more significant, mainly due to the higher sensitivity of 6.9V to low SST and the less influence of wind speed in the inversion of low SST. If the follow up satellite of FY 3 can carry 6.9 GHz channel, the retrieval accuracy of the low SST particularly at the higher latitudes will be further improved.