Line-of-sight optical turbulence and wind profile monitoring during free-space optical communication links

The reliability of future free-space optical communication (FSOC) links between satellites and the ground namely depends on accurate characterization of atmospheric turbulence along the optical path, which is critical for both performance prediction and the development of effective mitigation strategies. We present and validate two complementary approaches to extract, in real time, optical turbulence (OT) and wind information from adaptive optics telemetry acquired with a single Shack-Hartmann wavefront sensor during satellite downlinks, complemented with data from an external weather station. The first method provides fast and robust estimates of integrated OT parameters, while the second extends the SCO-SLIDAR framework to reconstruct detailed refractive index structure parameter ( C n 2 ) and wind profiles along the line of sight. The consistency between the two approaches is demonstrated through laboratory validation with a turbulence emulation bench and real-world application to data collected at the FEELINGS optical ground station. These results pave the way for automated OT characterization at FSOC sites, while also highlighting current limitations posed by underlying assumptions, such as Taylor’s frozen-flow hypothesis.