Passive Satellite Communication

A number of communications capabilities are noted as desirable goals and the characteristics of passive satellite reflectors are cited as a means of achieving them. Goals noted are the attainment of transoceanic ranges, high communications traffic per satellite, low launching and operating costs, high reliability, simplicity of operation, and long useful life of satellites. The properties of various types of passive reflectors are discussed and the characteristics of the sphere are shown to be particularly advantageous. Passive satellite communications systems are compared with current tropospheric scatter systems and are shown to be one order of magnitude better, using power per channel per unit range as a criterion. Some attention is given to Doppler shift as it bears upon the problem of transmitter-receiver channel coordination, satellite acquisition, and tracking.