Modelling and analysis of flight dynamics influences on the spatial acquisition and tracking performance of the TESAT laser communication terminal

Tesat Spacecom has been conducting successfully LEO-LEO (2008-2015) and LEO-GEO (starting October 2014) optical inter-satellite communication links utilizing laser communication terminals (LCT) built by Tesat-Spacecom funded by DLR. Even tough sophisticated test facilities are available certain functions of the LCT cannot be tested on ground because the effects of 45000 km distance between terminals cannot be reproduced in the laboratory. However, the effects of distance are of particular interest for the beaconless spatial acquisition algorithm, therefore two simulation tools have been developed to aid system and satellite design. To verify the simulation tools an analytical expression was developed to calculate the hit probability for Gaussian distributed vibration. Further verification was conducted utilizing telemetry data of in orbit links over the last 7 years. We present the concept of the simulation tools as well as the utilization for satellite and LCT design and for link commissioning. Also a comparison of LEO-LEO and LEOGEO system link commissioning phase regarding spatial acquisition will be presented Details of beaconless spatial acquisition algorithm can be found in [1]