利用布设在敦煌辐射校正场的自动化观测设备,对Hyperion高光谱遥感器开展定标试验;详细描述自动化定标的原理和方法,明确定标流程;针对高光谱遥感器的特点建立参考反射率数据库,以解决通道反射率与参考反射率光谱形状不匹配的问题;在2016年10月至2017年4月期间,对Hyperion高光谱遥感器共完成4次有效的自动化定标试验,并将试验结果与Hyperion高光谱遥感器观测的表观辐亮度进行比对验证。结果表明:在420~1044 nm光谱范围内,场地自动化定标得到的表观辐亮度与卫星观测的表观辐亮度的相对偏差小于5%,标准方差小于2.3%;场地自动化定标结果与高光谱星上观测结果具有较高的一致性和稳定性。所提方法可以应用于高光谱遥感器的高频次在轨辐射定标。

In this study, the calibration tests were conducted on the Hyperion hyperspectral remote sensor using the automated observation equipment at the Dunhuang radiometric calibration site. This paper details the principle and method of automated calibration and specifies the applied calibration process. A reference reflectance database was established to solve the problem of mismatch between the channel reflectance in the hyperspectral remote sensor and the spectral shape of the reference reflectance. The results of the four effective automated calibration tests performed on Hyperion from October 2016 to April 2017 were compared with the apparent radiance observed by Hyperion. The results show that the relative deviation between the apparent radiance obtained from the site-automated calibration and that from the satellite observation is less than 5% with a standard deviation of less than 2.3% within the 420-1044 nm spectral range. The site-automated calibration results are found to be highly consistent and stable with respect to the hyperspectral satellite observations, indicating that the proposed method can be applied to the high-frequency on-orbit radiometric calibration of hyperspectral remote sensors.