TMI 10.7 GHz低分辨率亮温资料的细化处理方法研究

Research on the resolution enhancement of brightness temperature at TMI 10.7 GHz

由于良好的穿透性,被动微波低频通道探测经常用于卫星遥感中,但其较粗的空间分辨率容易导致像元充塞效应,且无法直接匹配高频通道的细致分辨率,严重影响到微波低频观测资料的使用.以TMI 10.7GHz通道探测数据为对象,探讨如何便捷有效地提高微波低频数据的分辨率.首先以TMI 85.5GHz垂直极化通道探测分辨率(约5km)为基准,利用就近取值法、距离反比权重法和动态最小二乘曲面拟合法这3种方法做算法进行自检验分析.对比结果表明,最优方法为动态最小二乘曲面拟合法,距离反比权重法次之,就近取值法效果最差.在此基础上,选取洋面(170°E～180°E,10°N～20°N)、陆面(110°W～100°W,29°N～38°N)、海陆交界区(140°E～150°E,13°S～3°S)3个不同的区域进行TMI 10.7GHz与85.5GHz两套观测数据的匹配,并将匹配结果应用到台风个例分析中.研究结果为实现在85.5GHz高频通道的细致水平分辨率上,统一高低频通道观测资料的计算分辨率,得到多通道被动微波融合亮温资料提供了依据。

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 10. 7 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 85. 5 GHz. Results show that the best method for self-verification is movin frill A 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 10. 7 GHz and 85.5 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 85.5 GHz, and for producing a set of multichannel passive microwave data with fine calculated resolution.