Elevation

Elevation is the angle between the line of sight from an Earth station to a satellite and the local horizontal plane (horizon) at the Earth station. Elevation strongly influences propagation losses and minimum look-angle constraints, particularly at higher frequencies. Azimuth is the horizontal angle, measured in the local tangent plane at the Earth station, between a reference direction (usually true north) and the projection of the satellite line of sight onto that plane. Azimuth is commonly measured clockwise from true north, though other conventions are sometimes used.