无人机多光谱传感器场地绝对辐射定标研究

2010年10月14日无人机遥感载荷验证场科学实验在内蒙古乌拉特前旗展开，这是我国首个航空遥感定标验证场的首次科学实验。通过验证场实验数据及制作的朗伯特性好的六块高光谱辐射特性靶标，采用反射率基法对搭载在无人机平台上的宽视场多光谱相机进行了场地绝对辐射定标。结果显示，对于成功获取影像的绿光、红光及近红外通道的绝对定标结果中，计数值(DN值)与辐射传输计算得出的表观辐亮度之间的线性相关系数优于99%。经误差分析得到不确定度为5.19%，优于验证场课题要求的6%。定标结果表示，验证场所配备之高光谱辐射特性靶标适用于机载多光谱载荷的场地绝对定标，且定标结果可靠，可以用于地物参数的反演。

In-Flight Absolute Radiometric Calibration of UAV Multispectral Sensor

Based on the data of the scientific experiment in Urad Front Banner for UAV Remote Sensing Load Calibration Field project, with the help of 6 hyperspectral radiometric targets with good Lambertian property, the wide-view multispectral camera in UAV was calibrated adopting reflectance-based method. The result reveals that for green, red and infrared channel, whose images were successfully captured, the linear correlation coefficients between the DN and radiance are all larger than 99%. In final analysis, the comprehensive error is no more than 6%. The calibration results demonstrate that the hyperspectral targets equipped by the calibration field are well suitable for air-borne multispectral load in-flight calibration. The calibration result is reliable and could be used in the retrieval of geophysical parameters.