Tracking in a Ground to Satellite Optical Link: Effects due to Lead-ahead and Aperture Mismatch

摘要

Establishing a link between a ground station and a geosynchronous orbiting satellite can be aided greatly with the use of a beacon on the satellite. A tracker, or even an adaptive optics system, can use the beacon during communications activities to correct beam pointing for atmospheric turbulence and mount jitter effects. However, the pointing lead-ahead required to illuminate the moving object and an aperture mismatch between the tracking and pointing apertures can limit the effectiveness of the correction as the sensed tilt will not be the same as the tilt required for optimal transmission to the satellite. In this paper we present an analytical model that addresses the combined impact of these tracking issues in a ground-to-satellite optical link. The analysis considers geosynchronous Earth orbit satellites as well as low Earth orbit satellites.