Non-synchronous Satellite

A non-synchronous satellite is a satellite whose orbital period is not equal to the Earth’s sidereal rotation period and therefore does not remain fixed relative to the Earth’s surface. As a result, the subsatellite point moves with time, and the satellite appears to drift relative to an Earth-based observer. Non-synchronous satellites may operate in prograde or retrograde orbits and include most LEO, MEO, and HEO systems. In contrast to geostationary satellites, non-synchronous satellites provide time-varying coverage of a given location. Earth stations communicating with non-synchronous satellites generally require tracking antennas or electronically steered beams.