ISPRS-Annals ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences ISPRS-Annals ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci. 2194-9050 Copernicus Publications Göttingen, Germany 10.5194/isprs-annals-V-1-2022-195-2022 CALIBRATION OF A LIGHT HEMISPHERICAL RADIANCE FIELD IMAGING SYSTEM Lei M. 1 Thom C. 1 Meynard C. 1 Muller J.-M. 1 LASTIG, Univ Gustave Eiffel, ENSG, IGN, F-94160 Saint-Mande, France 17 05 2022 V-1-2022 195 202 Copyright: © 2022 M. Lei et al. 2022 This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/ This article is available from https://isprs-annals.copernicus.org/articles/isprs-annals-V-1-2022-195-2022.html The full text article is available as a PDF file from https://isprs-annals.copernicus.org/articles/isprs-annals-V-1-2022-195-2022.pdf

A light hemispherical radiance field imaging system based on fish-eye camera was developed for the measurement of the surface incident radiance in an urban environment, which is often affected by radiometric heterogeneity problems. A linear radiometric model and a polynomial fish-eye lens model are used. A temperature-dependent dark level model is proposed to improve the dark correction for high dynamic range photography. This paper describes the calibration procedure for spectral and geometrical radiance field measurements and presents the results of the calibration. The spectral radiometric calibration error is 2.07%, 1.34%, and 0.98% for blue, green, and red bands, respectively. The mean geometrical calibration error is 2.037 pixels.