A Study On Deviation Correction Of Brightness Temperatures Observed With A Ground-based Microwave Rediometer And Analysis For Response To Cloud

The ground-based microwave radiometer is a promising meteorological observation instrument which is applied in remote sensing technology. Compared with conventional radiosonde data, it has a much shorter observation interval and more sufficient atmosphere information. As a result, it can greatly make up the shortcoming of the conventional radiosonde observation, and it can be more generally applied in remote sensing technology.In this paper, taking a multi-channel microwave radiometer in Beijing for example, we analyzed the continuity of the "clear sky" brightness temperature data observed at eight and twenty o’ clock (BT) during the24months in both2010and2011with the purpose of the brightness temperature data quality control. Using the atmospheric profile data from independent sources such as NCEP, we calculated the brightness temperatures through the radiative transfer equation and tested the consistency between the observed brightness temperatures and the simulated results in "clear sky" condition. It has been found that the problem of discontinuous and inconsistency in observations is due to "Liquid Nitrogen Calibration" and "moving" which happened successively to the radiometer. And correction for these influences based on piecewise fitting has been realized and the continuity and consistency of the observed brightness temperature data has been improved. It shows that quality control on the brightness temperature observations is necessary before further applications.Cloud has an effect on the brightness temperature of microwave channel,each channel and the affected is different. Therefore, the change in brightness temperature depends on the cloud base height, the thickness and cloud water concentration of three parameters.Uses microwave radiation transmission equation derivation has inferred the observed brightness temperatures and cloud parameter (the cloud base height, the thickness and cloud water concentration) of relationship, and uses standard atmospheric and set of27group cloud parameter simulation calculation has common of13a channel of bright temperature data, established has bright temperature and cloud parameter relationship type, and anti-performances cloud parameter.