采用双权重算法进行FY-3A微波湿度计资料质量控制试验

针对FY-3A卫星微波湿度计MWHS(Microwave Humidity Sounder)资料的质量控制进行研究.选用2010年冬季1月17-23日FY-3A微波湿度计MWHS LlC格式的全球观测资料作为研究对象,采用双权重算法对观测增量O-B进行质量控制,其中O是Fy-3A微波湿度计观测的亮度温度,B是基于NCEP GFS全球预报系统6h预报场用辐射传输模式RTTOV模拟的亮度温度值,目的是剔除受地表发射率或云影响的离群资料.结果表明,通过双权重的质量控制后,FY-3AMWHS3、4、5通道O-B的标准差明显减小了2～3K,同时,质量控制后O-B偏差和标准差随时间窗变化也很稳定,可见该方法除去异常资料的效果较为理想,能够应用到卫星资料的质量控制中.

Quality control for FY-3A microwave humidity sounder measurement using bi-weighting method

Quality control of FY-3A microwave humidity sounder (MWHS) measurement is the main purpose of this study. In this study, the global data in L1C format from January 17 to 23 in 2010 is chosen as research object. And bi-weight algorithm is used to do quality control for the value O-B in order to eliminate the outliers which are induced by surface emissivity and cloud. Value O is the actual observed radiation brightness temperature of FY-3A MWHS; value B represents simulated radiation brightness temperature of FY-3A MWHS, which is simulated by rapid radiation transfer mode RTTOV_9_3 (model background field is 6 h forecast field in NCEP GFS global forecast system). It shows that standard deviation of the value O-B in channel 3,4 and 5 has obviously reduced 2-3 K by bi-weight quality control method. In addition, the change of average deviation of value O-B with the change of time is also very stable after bi-weight quality control. It is thus clear that this QC method would remove the outliers effectively and can be used in quality control for satellites.