LASER SATELLITE COMMUNICATION-NETWORK - VIBRATION EFFECT AND POSSIBLESOLUTIONS

A number of serious consortiums develop satellite communication networ ks. The objective of these communication projects is to service person al communication users almost everywhere on earth. The intersatellite links in those projects use microwave radiation as the carrier: Free-s pace optical communication between satellites networked together can m ake possible high-speed communication between different places on eart h, Some advantages of an optical communication system over a microwave communication system in free space are 1) smaller size and weight, 2) less transmitter-power, 3) larger bandwidth, and 4) higher immunity t o interference. The pointing from one satellite to another is a compli cated problem due to the large distance between the satellite, the nar row beam divergence angle, and vibration of the pointing system. Such vibration of the transmitted beam in the receiver plane decreases the average received signal, which increases the bit error rate. In this p aper, we review I) the present status of satellite networks, 2) develo ping efforts of optical satellite communication around the world, 3) p erformance results of vibration effects on different kinds of optical communication satellite networks, and 4) seven approaches to overcome the problems caused by transmitter pointing vibration.