Joint NRL/NELC Optical-Satellite-Communication Atmospheric-Propagation Test Plan,
NAVAL RESEARCH LAB WASHINGTON D C
Pagination or Media Count:
An experimental program has been planned to test the hypothesis that optical communication systems based on the heterodyne principle can be used for practical Navy shipsatellite communications through clouds of moderate thickness. The Island of Hawaii has been chosen as the site of a major field effort by NRL and NELC because the trade winds drive typical marine orographic clouds through an elevated mountain pass reproducibly on a daily basis, the mountain pass is accessible by road, and as is summarized herein the clouds there have already been well studied. A theoretical formulation based on radiation transport theory shows that the reliability of an optical heterodyne communication system can be expressed as a function of the cloud properties. The experiments will test the relationship between a system carrier-to-noise ratio CN and cloud properties. They will establish the averaging times necessary for a meaningful CN, determine the relationship between CN and the optical-thickness and droplet-size parameters of the cloud, relate reproduction of clear-path CN values, averaged mean-square wavefront tilt received, and optical turbulence, and measure the reduction of CN in a cloud as the receiver or transmitter is pointed off-axis thus examining the security of a system.
- Non-Radio Communications