HJ-1B卫星热红外通道在轨场地定标与验证

HJ-1B thermal infrared band in-flight radiometric calibration and validation

在对热红外辐射计CE312定标的基础上,基于青海湖水面辐射校正场,采用CE312开展同步测量实验,对HJ-1B卫星热红外通道进行在轨绝对辐射定标。由于HJ-1B卫星在轨星上定标系统不稳定,高温点难以准确获取,因此分别使用单点法和两点法,对2010年8月1日和5日两组传感器入瞳等效辐亮度值和卫星通道计数值回归得到该卫星通道绝对定标系数,并使用内蒙达里湖水面辐射校正场2010年6月29日实测数据进行定标系数的验证工作。验证结果表明,青海湖场地两次定标系数有较好的一致性,定标结果稳定可信。两点法所得定标系数的精度高于单点法。

The in-flight radiometric calibration for thermal bands of HJ-1B was described using the test site, Qinghai-lake based on the calibration of the thermal-infrared field radiometer CE312. Because of the instability of the onboard calibration, the high temperature point was hard to obtain, the single-point and two-point calibration methods were used to calculate the calibration coefficients respectively. The results were validated by the data of June 29, 2010 at the Dali-lake test site. It shows that the calibration coefficients calculated by the data of Qinghai-lake have high reliability. And the comparison between the methods of single-point calibration and two-point calibration show that the accuracy of two-point calibration method is better than the single-point one.