The Comsat 13 and 18 GHz propagation experiment

The ATS-6 Comsat Propagation Experiment, designed to gather statistical data on attenuation by rain and snow at 13 and 18 GHz, is discussed. Signals from unattended ground transmitters at 25 locations in the eastern U.S. operating at 18 GHz and 13 GHz were transmitted to ATS-6, where the transponder converted the carriers to frequencies around 4150 MHz. These signals were then transmitted to the Comsat large horn antenna/data acquisition and receiving facility at Bangor, Maine, where each carrier was calibrated and digitally recorded once per second. Attenuation statistics for 40 carriers have been plotted. The experiment was conducted from July 1974 to May 1975 with excellent performance of the transponder.