Portal de Periódicos da CAPES

Some Technical Factors Affecting the Feasibility of Direct Broadcasting from Earth Satellites

1962; Society of Motion Picture and Television Engineers; Volume: 71; Issue: 6 Linguagem: Inglês

10.5594/j12121

0361-4573

Edgar T. Martin, George M. Jacobs,

Telecommunications and Broadcasting Technologies

Various technical factors affect the feasibility of broadcasting to the general public from satellites, the most satisfactory orbit for such satellites, and the order of satellite primary power that would be required for Band 7-MM (HF), Band 8-FM (VHF), Band 8-TV (VHF), Band 9-TV (UHF) and Band 10-TV (SHF) transmissions. These factors are discussed on the assumptions that no major changes will be made in present transmission standards, frequency allocations, or home receiving equipment; that equatorial synchronous orbit is considered the most satisfactory for broadcasting because it will permit uninterrupted transmission throughout the entire day and does not require complex tracking antennas for receiving, since a satellite in such an orbit remains stationary with respect to a given point on earth. — Chief among the many formidable technical problems still to be solved before high-quality broadcasting from space satellites can be considered feasible are the development of precise orientation and stabilization systems for accurately “aiming” the satellite's transmitting antenna, and the development of high-capacity power supplies and other system components of such size, weight and reliability that will permit continuous operation of a broadcasting station in a precise stationary orbit, without maintenance, for a period of time that will justify its operation economically.