Measuring the vertical profile of atmospheric turbulence with the laser communication relay demonstration downlink at Table Mountain Facility

To mitigate the impact of atmospheric turbulence on Free-Space Optical Communication (FSOC) systems, we present a novel turbulence profiling technique. A Ring Image Next Generation Scintillation Sensor (RINGSS), adapted for infrared wavelengths, has been deployed at the NASA/Jet Propulsion Laboratory's Table Mountain Facility. For the first time, we use the downlink from the Laser Communication Relay Demonstration (LCRD) satellite as a reference for atmospheric turbulence profiling. The LCRD beam allows for high signal-to-noise at all times of day through the same atmospheric channel as the optical ground station conducting the link. Results demonstrate the RINGSS measurement technique is robust even in strong daytime turbulence with comparison to other instruments and the benefits of using a laser downlink are significant. We therefore demonstrate that the concept of free-space optical communication turbulence profiling could be effectively used for 24-hour operational support to GEO feeder link stations.