Radiometric calibration of photographic camera with a composite plane array CCD in laboratory

To eliminate the serious vignetting phenomenon and to solve the difficulty of choosing a relatively positioning target value problems among CCDs during the radiometric calibration of the whole image plane of the photographic camera with a composite plane array CCD, a method for radiometric calibration of multi-CCDs was proposed. After the dark signal calibration on each pixel, the gray value of the pixel in the vignetting area was revised, and by choosing the appropriate relative calibration target gray value of the whole image plane, the radiometric calibration of the photographic camera with a composite plane array CCD was eventually completed. Through analysis of the gray distribution characteristics of vignetting area, the gray correction method for all kinds of explosion time and radiance was proposed. With calculation of fitting coefficient between each CCD gray value and the input radiance respectively, the coefficient with global minimum fitting error was chosen to calculate the relative calibration target gray value corresponding to radiance. After the radiometric calibration using this method, the non-uniformity of the whole image plane of the photographic camera with a composite plane array CCD is reduced from above 20% to better than 2%, and the accuracy of the absolute calibration is 4.23%. The result indicates that the proposed calibration method is appropriate for the calibration of composite planes array CCD. The accuracy of the calibration satisfies the radiometric calibration requirement of aerial cameras. © 2017, Science Press. All right reserved.