Close range radiometry for quantifying the spatial distribution of illumination on flat surfaces

Measuring the spatial distribution of irradiance on surfaces has extensive applications in various fields of heat transfer such as concentrating solar energy. In this paper, we have introduced a close range radiometry measurement method for flat surfaces employing camera calibration to extract illumination distribution data with high accuracy and resolution. The equations for quantifying the illumination profile on the target using the measured geometrical parameters have been introduced. The method developed in this work was experimentally demonstrated to have an accuracy of ±10% with additional improvement opportunities identified and discussed.