Architecture and Characteristics of Antenna Systems onboard Inmarsat Spacecraft for Mobile Satellite Communications

Abstract

This paper describes architecture and characteristics of special antenna systems onboard Inmarsat Geostationary Earth Orbit (GEO) spacecraft for Mobile Satellite Communications (MSC). These spacecraft provides satellite links for communications, tracking, monitoring and logistics solutions between mobile and personal units as a Mobile Earth Station (MES) and Gateways or Ground Earth Stations (GES) achieved via Geostationary Earth Orbit (GEO) satellite constellation. Inmarsat GEO MSS operator is deploying advanced technology and technique to deliver Voice, Data and Video (VDV) for all mobile applications worldwide, excluding Polar Areas. The Inmarsat organization received sufficient funds to implement at first solutions for maritime applications and in the next phase to develop additional services such as land (road and rail) and finally for aeronautical applications. The Inmarsat team overcame all the problems and challenges, gaining the attribute of only one global mobile satellite operator with a significant professional attribute. Regarding the improvement of the space segment and in particular the service for mobile and personal applications, antenna systems on the Inmarsat spacecraft are being considered. Modern spacecraft antenna characteristics and link performance with monobeam and multibeam antenna coverage are presented. Here are presented the possible basic types of antennas installed on board for MSC service.