Combining the 50-60 GHz and 118 GHz Passive Microwave Measurements for Surface Pressure Retrieval Over Oceans

Previous studies used 50-60 GHz or 118 GHz passive microwave measurements separately for surface pressure retrieval. To improve the retrieval accuracy, a joint retrieval method is proposed in this study to use the 50-60 GHz and 118 GHz passive microwave measurements simultaneously for surface pressure retrieval over oceans. Based on information content analysis and footprint matching, collocated passive observations of the two bands are obtained, and then are used to establish back-propagation neural network retrieval models. Using the 50-60 GHz passive observations of Microwave Temperature Sounder-II (MWTS-II) onboard the Fengyun-3D (FY-3D) satellite and the 118.75 GHz observations of the Microwave Humidity and Temperature Sounder (MWHTS) onboard the FY-3D satellite, joint retrieval experiments are completed. Experimental results show that when using the 50-60 GHz and 118.75 GHz oxygen absorption band together for surface pressure measurements, more surface pressure information and better retrieval accuracy can be obtained than using them separately.