机载数字航摄仪场地绝对辐射定标及验证分析

Test field absolute radiometric calibration and validation of aerial digital camera

针对遥感定量化中绝对辐射定标相关研究较少的问题,该文利用安阳试验场布设的8种不同反射率的固定靶标,采用反射率基法对机载数字航摄仪进行绝对辐射定标,分别用单点法、两点法和多点法得到不同的定标系数;为了验证辐射定标结果,选择另外4块不同颜色的靶标,分别对不同方法得到的定标系数进行验证评价。结果表明,单点法得到的定标系数平均误差最大,两点法和多点法的定标误差比较接近,多点法的平均定标误差最小。研究结果对于今后航空遥感相机的在轨定标具有一定的参考作用。

Absolute radiometric calibration is the prerequisite and foundation to realize quantitative remote sensing.In this study,reflectance-based vicarious calibration method was employed for digital photogrammetric sensor calibration.Single-site,dual-site and multi-site approaches were used to obtain radiometric calibration coefficients respectively by measuring the reflectance of eight different grayscale ground targets in Anyang test field.To validate the above mentioned calibrated results,another four grayscale ground targets were chosen.The results demonstrated that the mean error of calibration coefficients by single-site method was maximal and that by multi-site method was minimal,meanwhile the result by dual-site method was line with that by multi-site method.This investigation focused on in-flight radiometric calibration of airborne digital camera,which would provide referential experience for future study.