风云三号A星微波湿度计探测通道定标分析  

Calibration Analyses for Sounding Channels of MWHS Onboard FY-3A

作　　者：谷松岩[1] 郭杨 王振占 卢乃锰[1] 

机构地区：[1]中国遥感卫星辐射测量和定标重点开放实验室,国家卫星气象中心,中国气象局,北京100081 [2]中国科学院空间科学与应用研究中心,北京100081

出　　处：《气象科技进展》2013年第4期43-49,共7页Advances in Meteorological Science and Technology

基　　金：国家重点基础研究发展计划(973计划)项目2010CB951600);国家高新技术研究发展计划863计划)项目(2007AA12Z115)

摘　　要：微波湿度计装载在中国新一代极轨气象卫星风云三号卫星上，可完成全天候大气湿度信息的被动微波遥感探测。风云三号A星（FY-3A）微波湿度计（MWHS）在150～191GHz频率范围内有5个通道，为保证在轨定量应用，FY-3A发射之前，在2m真空罐（TVAC）中完成了MWHS真空试验，获得了接收机非线性等基本参数。FY-3A MWHS在轨运行的4年中，性能一直稳定，扫描周期间冷空和热源观测结果的变化一般在20个计数以内；绕地一圈的轨道观测中热源温度变化不超过0.5K。基于从TVAC试验中获得的非线性订正，FY-3A MWHS观测亮温与NOAA-17 AMSU-B及NOAA-18 MHS观测亮温有很好的一致性；FY-3A MWHS与NOAA-17 AMSU-B瞬时匹配点平均亮温差在183±1GHz通道小于1.0K。在观测场与背景场的比较分析中，FY-3A MWHS183.31±1GHz通道的观测和模拟亮温差与NOAA-18 MHS具有相同分布特性；而对183.31±7GHz通道而言，FY-3A MWHS与背景场更为吻合。分析表明，FY-3A MWHS数据将有助于数值天气预报。The Microwave Humidity Sounder(MWHS) is a five-channel microwave radiometer in the range of 150~191 GHz onboard FengYun 3(FY-3).Before the launch of FY-3A,the intensive thermal vacuum(TVAC) tests for MWHS had been carried out in a 2-m TVAC chamber,and the basic parameters such as receiver nonlinearity were obtained.Four-year operation shows that the performance of FY-3A MWHS remains stabile.The variations among space views and warm target views in the interval of scan lines were generally within 20 counts.In addition,the temperature fluctuation of the warm target in a single pass is within 0.5 K.Primarily,due to the nonlinearity correction obtained from the TVAC test,radiance measurements of MWHS agree well with NOAA-17 AMSU-B and NOAA-18 Microwave Humidity Sounder(MHS) data.Averaged brightness temperature differences between FY-3 MWHS and NOAA-17 AMSU-B,at simultaneous cross-overpass points,are less than 1.08 K for the channels at 183±1 GHz.In the observation-minus-background comparison,the observed and simulated brightness temperature biases of FY-3 MWHS and NOAA-18 MHS exhibit similar performance in the 183.31±1 GHz channel;but in the 183.31±7 GHz channel,MWHS agrees better with background.It is anticipated that FY-3 MWHS data will contribute to numerical weather prediction.

关 键 词：FY-3A MWHS 定标 交叉对比 

分 类 号：P414.4[天文地球—大气科学及气象学]