MWHTS clear sky observation brightness temperature selection method based on cloud water content inversion

Abstract

The invention discloses an MWHTS clear sky observation brightness temperature selection method based on cloud water content inversion, and the method comprises the steps: building the matching data ofan MWHTS observation brightness temperature and a climate data set in time and space, calculating a corresponding MWHTS simulation brightness temperature, and forming an analysis data set and a verification data set; taking the cloud water content 0 in the analysis data set as a strict clear sky threshold, selecting the MWHTS strict clear sky observation brightness temperature, and adjusting thestrict clear sky threshold by taking the calculation precision of the MWHTS simulation brightness temperature under the strict clear sky as a standard to form a corresponding clear sky threshold; based on the analysis data set and the BP neural network, establishing an optimal inversion model of MWHTS observation brightness temperature inversion cloud water content; using the MWHTS observation brightness temperature in the verification data set to invert the cloud water content, and selecting the MWHTS clear sky observation brightness temperature according to the cloud water content inversionvalue and the clear sky threshold. According to the method, the MWHTS observation brightness temperature can be directly utilized to realize effective selection of the MWHTS clear sky observation brightness temperature, the accuracy is high, and the operation is simple and feasible.

Description

technical field [0001] The invention belongs to the technical field of microwave remote sensing, and in particular relates to a brightness temperature selection method for MWHTS clear sky observation based on cloud water content inversion. Background technique [0002] The Microwave Humidity Temperature Detector (MWHTS) is an important payload on Star C of Fengyun-3 and star D. It is the first microwave radiometer in the world that integrates a hygrometer and a thermometer. The MWHTS has eight temperature detection channels (channels 2-9 ) and five humidity detection channels (channels 11-15) and two window channels (channel 1 and channel 10), which can realize the simultaneous detection of atmospheric temperature, water vapor parameters and surface parameters. [0003] Compared with the clear sky atmosphere, the radiative transmission of microwaves in the cloudy and rainy atmosphere will be affected by the emission and scattering effects of clouds and rain, which increases ...

AI Technical Summary

Problems solved by technology

[0004] When dealing with the problems related to the forward modeling of spaceborne microwave radiometers, setting the threshold value of atmospheric relative humidity and using infrared cloud products are common methods to select clear sky observation brightness temperature from spaceborne microwave radiometer observation brightness temperature, but the spaceborne microwave radiation When using these two methods to select clear-sky data, it is necessary to complete the matching with atmospheric relative humidity or infrared cloud products, which seriously affects the direct application of the data. Not applicable in inversion

In the inversion application of the brightness temperature observed by the spaceborne microwave radiometer, the threshold value can usually be formed according to the statistical relationship between the brightness temperature observed by the microwave radiometer channel to judge the clear sky, but the accuracy of this method for judging the clear sky data is low. In addition, the establishment of the threshold value in this method is highly dependent on the local atmospheric state, and it is not suitable for the selection of brightness temperature in clear sky observations in a large area.

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