Preliminary Results of an Upgraded Atmospheric Visibility Monitoring Station

The Atmospheric Visibility Monitoring (AVM) station located at the Table Mountain Facility (TMF) in Wrightwood, California, recently has undergone a significant hardware and software upgrade. This upgrade has enhanced our ability to pursue the AVM program goals, which are to gather atmospheric optical transmission data at specific wavelengths and to build statistical attenuation models for space-to-ground optical communication links. The AVM stations derive information about atmospheric transmission by continuously monitoring and recording star intensities. The TMF AVM has been operational since October 1999, and enough data have been accumulated to provide a first glimpse into the capabilities of the new system. In doing so, problems were identified in the star identification software routines implemented as a part of the on-site image processing, and new processing routines have been developed. By post-processing of stored images, the procedure has resulted in a 33 percent increase in viable star images. The upgraded system continues to prove to be more convenient to maintain and holds the promise of significant improvements in the quality and quantity of the usable data.