光子学报, 2020, 49 (5): 0528002, 网络出版: 2020-06-04
基于青海湖辐射校正场的FY3D/MERSI-II卫星遥感器热红外波段在轨辐射定标
On-orbit Radiometric Calibration for Thermal Infrared Band of FY3D/MERSI-II Satellite Remote Sensor Based on Qinghai Lake Radiation Calibration Test-site
遥感 绝对定标 精度分析 热红外 辐射传输 Remote sensing Absolute calibration Accuracy analysis Thermal infrared Radiative transfer
摘要
2018年8月在青海湖辐射校正场开展了针对FY3D/MERSI-II卫星遥感器热红外通道的在轨绝对辐射定标试验.采用走航式测量的方式获取了青海湖水表光谱辐亮度数据, 结合探空数据, 并基于 辐射传输模型计算出卫星过境时刻的入瞳辐亮度和亮温, 实现了对FY3D/MERSI-II卫星遥感器热红外通道24(10.26~11.26 μm)和通道25(11.50~12.50 μm)的在轨辐射定标.利用国际公认精度的 AQUA/MODIS和NPP/VIIRS卫星遥感器对在轨辐射定标方法进行精度评估, 在10.26~11.26 μm和11.50~12.50 μm波段范围, 通道亮温的平均偏差分别小于0.5 K和1.0 K, 表明基于青海湖辐射定标场 的在轨辐射定标方法具有较好的定标精度, 获得的定标结果合理可靠.将利用青海湖进行的在轨定标结果与星上定标结果进行比较, 在10.26~11.26 μm和11.50~12.50 μm波段范围, 通道亮温的平 均偏差分别小于0.5 K和1.25 K, 表明FY3D/MERSI-II在轨运行稳定.本次试验检验了FY3D/MERSI-II星上定标结果, 也为FY3D/MERSI-II遥感数据的定量化应用提供了保障.
Abstract
In August 2018, an on-orbit absolute radiometric calibration test for the thermal infrared channel of FY3D/MERSI-II satellite remote sensor was carried out at the Qinghai lake radiation correction test-site. The spectral radiance data of Qinghai Lake was obtained by means of fixed-point measurement. The sounding data were input to radioactive transfer model to compute the at-sensor radiance and brightness temperature of the satellite, and the calibration coefficients for thermal infrared channel 24 (10.26~11.26 μm) and channel 25 (11.50~12.50 μm) of FY3D/MERSI-II were calculated. AQUA/MODIS and NPP/VIIRS satellite remote sensors which have high calibration accuracy were used to evaluate the accuracy of the on-orbit radiometric calibration method. The average deviation of the channel brightness temperature is less than 0.5 K in the range of 10.26~11.26 μm and less than 1.0 K in the range of 11.50~12.50 μm, indicating that the on-orbit radiometric calibration method has better calibration accuracy, and the calibration results are reasonable and reliable. Comparing the on-orbit calibration results using the Qinghai Lake with the on-board calibration results, in the range of 10.26 ~ 11.26 μm and 11.50 ~ 12.50 μm, the average deviation of the channel brightness temperature is less than 0.5 K and 1.25 K, respectively. It shows that FY3D/MERSI-II runs stably on orbit. This test verified the FY3D/MERSI-II on-board calibration results, and provided a guarantee for the quantitative application of FY3D/MERSI-II remote sensing data.
张允祥, 李新, 张孟, 康晴, 韦玮, 郑小兵, 张勇. 基于青海湖辐射校正场的FY3D/MERSI-II卫星遥感器热红外波段在轨辐射定标[J]. 光子学报, 2020, 49(5): 0528002. ZHANG Yun-xiang, LI Xin, ZHANG Meng, KANG Qing, WEI wei, ZHENG Xiao-bing, ZHANG Yong. On-orbit Radiometric Calibration for Thermal Infrared Band of FY3D/MERSI-II Satellite Remote Sensor Based on Qinghai Lake Radiation Calibration Test-site[J]. ACTA PHOTONICA SINICA, 2020, 49(5): 0528002.