Evaluation and Improvement of the Quality of Ground-Based Microwave Radiometer Clear-Sky Data

To assess the quality of retrieved products from ground-based microwave radiometers, “clear-sky” Level-2 data (LV2) (profiles atmospheric temperature and humidity) filtered through a radiometer in Beijing during 24 months January 2010 to December 2011 were compared with radiosonde data. Evident differences revealed. Therefore, this paper investigated an approach calibrate observed brightness temperatures by using model-simulated as reference under clear-sky conditions. The simulation was completed radiative transfer model National Centers for Environmental Prediction final analysis (NCEP FNL) that are independent system. Then, least-squares method used invert calibrated humidity profiles. A comparison between retrievals showed calibration observations is necessary, can improve inversion profiles original LV2 products. Specifically, consistency clearly improved: correlation coefficients increased, especially, coefficient water vapor density increased 0.2 0.9 around 3 km height; bias decreased nearly zero at each RMSE (root mean squared error) profile more than 1 degree most heights; greater 4 g/m3 less 1.5 decrease all other heights also noticeable. In paper, evolution process given example, high-temporal-resolution after control obtain every two minutes. characteristics cannot be seen conventional (twice daily) obtained radiometer. This greatly compensates limited temporal coverage presented valuable reprocessing historical observations, which have been accumulated years less-calibrated radiometers.