Photometric calibration of the Surveyor television system

A complete prelaunch calibration was performed on each Surveyor television system to allow accurate reconstruction of the televised pictures. Photometric calibration data served to define system performance in terms of lunar luminance units, thereby allowing the television camera to be used in determining relative and absolute luminance values of selected portions of the lunar terrain. Development of such calibration data required the evaluation of a correction factor such that lunar performance could be predicted from measurements obtained with conventional light sources.