Citation
Abstract
Laser beams propagating through the atmosphere are impacted by turbulence, which may cause random beam-steering and phase-front distortions that deteriorate the quality of the transmitted beam. Random beam-steering is particularly serious in groundto-space communications applications, where a small error in the direction vector of the transmitted beam close to the ground may result in a large displacement at the spacecraft, causing deep fades that degrade communications performance. It is therefore important to compensate for beam-steering and higher-order distortions as the beam propagates through the atmosphere. This can be accomplished by using the downlink signal transmitted by the spacecraft as a reference to help characterize the main components of atmospheric turbulence at various distances from the transmitter along the line of sight, thus reducing the effects of beam-steering and higher-order distortions at the spacecraft. This paper describes and experimentally demonstrates a system concept that identifies two or more turbulent layers along a horizontal path and determines their distance, and can be expanded in the future to characterize wavefront distortions caused by each layer.
Details
- Volume
- 42-239
- Published
- November 15, 2024
- Pages
- 1–25
- File Size
- 13.2 MB