Assessment Of The Radiometric Accuracy In A Target Less Work Flow Using Pix4D Software

To compute reflectance from images taken by multispectral sensors aboard UAVs, most users perform radiometric calibration using a target with known reflectance. This workflow is error-prone and not practical for large data acquisitions. With recent advances in multispectral cameras, sensors which measure the sky down-welling irradiance have become available. This enables radiometric calibration without using a target. In this paper, we assess the radiometric accuracy of target less acquisition using a Sequoia + camera ¹ for both at-ground and in-flight measurements. Most of the measured control points exhibit a high correlation of 0.98 in the computed reflectance factor with respect to the expected values.