中国遥感卫星辐射校正场热红外通道在轨场地辐射定标方法精度评估

Accuracy Evaluations of the CRCS In-orbit Field Radiometric Calibration Methods for Thermal Infrared Channels

基于中国遥感卫星辐射校正场对在轨运行的遥感卫星热红外通道进行在轨绝对辐射定标,利用TERRA/AQUA MODIS卫星观测数据,对中国遥感卫星辐射校正场热红外通道在轨场地辐射定标方法进行精度评估与分析。将MODIS观测的入瞳亮温与外场实测数据通过辐射传输模式模拟到卫星入瞳的亮温进行比较,结果表明对热红外窗区通道的定标精度优于1.0 K（@300 K）。目前应用于我国在轨风云气象卫星热红外通道的中国遥感卫星辐射校正场绝对辐射定标方法本身具有很好的定标精度：对10.5～11.5μm通道,误差在0.747 K以内;对11.5～12.5μm通道,误差在0.851 K以内。

In order to achieve the in-orbit absolute radiometric calibration of the operational meteorological satellites＇ thermal infrared channels,China Radiometric Calibration Sites（ CRCS） were established and the accuracy of the CRCS in-orbit field absolute radiometric calibration methods（ FCM） for thermal infrared channels（ TIR） was evaluated and analyzed based on TERRA / AQUA MODIS observations. Comparisons between the MODIS at pupilbrightness temperatures（ BTs） and the simulated BTs at the top of atmosphere using radiative transfer model（RTM） based on field measurements showed that the accuracy of the current in-orbit field absolute radiometric calibration methods was better than 1. 0K（ @ 300K） in thermal infrared channels. Therefore,the current CRCS field calibration method for TIR channels applied to Chinese meteorological satellites was with favorable calibration accuracy： for 10. 5 ～ 11. 5 μm channel was better than 0. 747 K and for 11. 5 ～ 12. 5 μm channel was better than0. 851 K.