trace au sol

CONT: Les écarts d'orbite d'Envisat ne devraient pas engendrer d'écarts supérieurs à +/- 1 km par rapport à la trace au sol de référence.
OBS: trace au sol : terme uniformisé par le Groupe de travail de la terminologie de RADARSAT-2 (GTTR).

OBS: The inclination of a satellite, together with its orbital altitude and the period of its orbit, creates a track defined by an imaginary line connecting the satellite and the Earth's center. The intersection on the line with the Earth's surface is the subsatellite point. As the Earth turns on its axis and the satellite orbits overhead, a line is created by the satellite's apparent path over the ground (the series of subsatellite points connected). A geostationary satellite has an inclination of essentially zero, and, because its orbital period exactly matches the Earth's rotation, its ground track is reduced to an apparent stationary point on the equator.
OBS: ground track: term officially approved by the RADARSAT-2 Terminology Approval Group (RTAG).