Technology, data bases and system analysis for space-to-ground optical communications

Optical communications is becoming an ever increasingly important option for designers of space-to-ground communications links, whether it be for government or commercial applications. The technology being developed by NASA for use in space-to-ground optical communications is presented. Next, a program which is collecting a long term data base of atmospheric visibility statistics for optical propagation through the atmosphere is described. Finally, a methodology for utilizing the statistics of the atmospheric data base in the analysis of space-to-ground links is presented. This methodology takes into account the effects of station availability, is useful when comparing optical communications with microwave systems, and provides a rationale for the establishing the recommended link margin.