Research on the resolution enhancement of brightness temperature at TMI 107 GHz

The relatively coarser spatial resolution of low frequency channels of passive microwave remote sensing tends to cause the beam-filling effect，which essentially affects the retrieval of atmospheric parameters and efficiency of usage. With the TMI 107 GHz measurements as the target, discussions were conducted on how to effectively enhance the data resolution of microwave low frequency channels. Firstly， nearest neighbor interpolation, inverse distance weighted and moving least-squares were analyzed separately based on the spatial resolution (about 5 km) of the vertical polarization channel at TMI 855 GHz. Results show that the best method for self-verification is moving least-squares, followed by inverse distance weighted, and the worst one is nearest neighbor interpolation. Then, three typical areas of ocean (170°E~180°E, 10°N~20°N), land (110°W~100°W, 29°N~38°N) and costal regions (140°E~150°E, 13°S~3°S) were chosen for matching resolution at TMI 107 GHz and 855 GHz. Finally, an application to a typhoon case was put forward. This study provides a basis for enhancing the coarse resolution at TMI low frequencies to a fine one at 855 GHz, and for producing a set of multichannel passive microwave data with fine calculated resolution.