Telemetry, command and ranging system of geo spacecraft

The article describes the telemetry, command and ranging system of GEO spacecraft. It addresses RF signals passage in ground-to-spacecraft path. Results of RF link budget calculations are presented. The article also addresses unaccountable parameters of using onboard and ground equipment having performances required by the link budget. System operation in ranging mode is described, as well as the existing problems of its usage. Prospects of existing disadvantages handling and system performance improvement were given.