Medium-capacity space-communication terminal

System design considerations for an air-transportable ground station for satellite communication are discussed and system specification and performance figures derived. A general description is given of the arrangement of the component units, including the 30ft diameter aerial, together with general data on the operating facilities provided. Environmental conditions envisaged included both the Arctic and the tropics and heating/cooling equipment was provided; for Arctic operation an inflatable radome was used, but the aerial was designed to survive winds exceeding 100 miles/h. Tracking accuracy of the parabolic aerial was maintained in gusts of up to 50 miles/h and a zenithal pass followed satisfactorily by taking advantage of the beam-width to allow time for the necessary 180deg rotation in azimuth. Automatic tracking used a monopulse technique, but manual and programmed control was also available. Command, control and telemetry facilities were provided at v.h.f. (100 to 150 Mc/s); the main transmitter (10 kW) and receiver could operate in the 2, 4, 6 or 8 Gc/s bands as required.