A Quality Control Procedure For FY-3 Microwave Radiance Data

Abstract:That China's first FY-3 satellite launched successfully will provide more useful satellite radiance data to numerical weather-prediction (NWP) system. Statistical feature analysis and a quality control procedure must be applied to the radiance before implementing the application of the direct assimilation of the radiance data from Micro Wave Temperature Sounder of FY-3. In this study, biweight estimation was used for observation incremental (difference between observation and background simulated by RRTOV9 based on the NCEP Final Analysis) during the quality control procedure. The quality control scheme is divided into two steps:a range check and identification of outliers, to remove the outliers influenced by emissivity of surface and cloud.Finally, the biweight estimation was used to observation incremental, which is the difference between brightness temperature data observed form microwave thermometer and background simulated by RRTOV9 based on the NCEP Final Analysis for a week from January lth 2010 to January 7th 2010 during the quality control procedure. We analyze its deviation and standard deviation statistically before and after the quality control procedure and the proportion of outliers eliminated accounted for total observation. Getting the further verification of the effect that biweight estimation is applied to brightness temperature data from microwave thermometer. Preliminary results show that standard deviation of observation increment significantly reduced and become more stable after quality control procedur, deviation closes to unbiased normal distribution and gets big improvement in general.