Accurate calibration is needed for Quantitative application of space-borne passive microwave radiometers. In this paper, the surface target which can be taken as the calibration reference target are studied, and the emission model was developed for the emissivity computation for these targets. It is found that in dense covered forest area, for 19-89GHz frequencies, microwave radiation brightness temperature can be calculated with an accuracy of IK. For the frequency channel as low as 6 and 10 GHz, the desert area such as Sahara can be taken as reference calibration target And the established model accuracy in desert area is within 2K by using the NCEP reanalysis dataset as input.%从被动微波辐射计在轨辐射定标的角度出发,选取亚马逊雨林作为高温地面目标,利用DMSPF13-SSM/I数据和NCEP数据对研究区19-89GHz辐射特性进行分析.研究发现,利用辐射亮温稳定的热带雨林作为地面目标,对19-89GHz的频段,微波辐射亮温计算精度可以达到1K以内;对于6和10GHz这样的低频通道,撒哈拉沙漠是一个可供选择的地面目标,根据所建立的亮温计算模型,利用数值预报分析场NCEP数据作为输入,其亮温计算精度在2K以内.
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