采用双权重算法进行FY-3A微波湿度计资料质量控制试验

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

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 L1C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6 h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-3AMWHS 3、4、5通道O-B的标准差明显减小了2～3 K,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 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 cho- sen 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 tem- perature of FY-3A MWHS, which is simulated by rapid radiation transfer mode RrI^FOV 9 3 （ model background field is 6 h forecast field in NCEP GFS global forecast system）. It shows that standard devia- tion 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 effec- tively and can be used in quality control for satellites.