Spectral matching factors between GaAs and multialkali photocathodes and reflective radiation of objects

Spectral matching factors for starlight and full moon illumination conditio ns, GaAs and multialkali photocathodes, and some commonly encountered objec ts are computed and compared. For the S-251 photocathode, these factors for combinations of dark green paint, green vegetation, and rough concrete are 0.27, 0.13, and 0.23 in clear starlight conditions and 0.55, 0.28, and 0.4 9 in full moon conditions, respectively. For the S-252 photocathode, the fo rmer are 0.57, 0.48, and 0.56 and the latter are 0.72, 0.68, and 0.72. Fina lly, for the GaAs photocathode, they are 0.58, 0.65, and 0.61 and 0.45, 0.6 9, and 0.52, respectively. These values can be used for realistic estimates of the field performance and to optimize the design of night vision system s. (C) 2001 Society of Photo-Optical instrumentation Engineers.