Photometric recovery of Apollo metric imagery with Lunar-Lambertian reflectance

Abstract

The scene radiance of the lunar surface, the reflectance of which depends on the topographical configuration is reconstructed from Apollo orbital imagery. The pixel value is determined by the camera response of sensor exposure which is proportional to scene radiance, lunar reflectance and exposure time. Based on the Lunar-Lambertian reflectance model, the point-wise reflectance is pre-calculated from the Apollo metadata and digital elevation models. The surface radiance, exposure time and camera response are estimated by the maximum likelihood method for sensor exposure which follows a continuous Poisson distribution with the mean of surface radiance. An alternating parameter scheme is proposed to determine the one family of parameters from the others. The photometric recovery of ortho-images derived from Apollo 15 metric camera imagery is presented to show the validity of the proposed method.