利用大洋浮标数据和NCEP再分析资料对FY-2C红外分裂窗通道的绝对辐射定标

介绍利用大洋浮标数据和NCEP再分析资料对FY-2C红外分裂窗通道进行在轨绝对辐射定标的方法,并选择了2006年10个时次的卫星数据进行辐射定标试验.将利用这种方法获得的定标结果与FY-2C卫星数据产品中提供的定标查找表进行比较分析,结果表明两套不同的定标系数反演的大气层顶(TOA)亮度温度的主要差别集中在云顶、冰雪覆盖区域等低温像元;而在常温区的陆表和海表像元定标结果差别较小,反演的TOA亮温差在2K左右.提出的替代定标方法可以极大地提高定标频次,为实现FY-2C红外分裂窗通道的实时绝对辐射定标提供了重要的方法基础.

Absolutely radiometric calibration of FY-2C infrared split-window channels using sea buoy data and NCEP reanalysis data

A method of absolutely radiometric calibration of FY-2C infrared split-window channels using sea buoy data and NCEP reanalysis data was introduced. In 2006, ten times remote sensing data were selected to obtain the radiometric calibration coefficients. The calibration results obtained from this new method were compared with the product brightness temperature look up tables. The results show that the biggest differences between the top of atmosphere (TOA) brightness temperatures inversed from these two suits of calibration coefficients were mainly located on low surface temperature pixels, such as top of clouds and snow covered areas and in normal temperature pixels like land and sea surface areas, the differences were mainly around 2K. This new vicarious calibration method can increase the calibration frequency and provide a methodological foundation for the Real-time radiometric calibration of FY-2C infrared split-window channels.