In a sun-synchronous orbit, the satellite passes over the same part of the Earth at approximately the same local time each day. The satellite's orbital plane appears to be fixed with respect to the sun. For example, the satellite will pass over the Great Lakes at the same local time for each ascending pass and at the same local time of day for each descending pass. The times are different for ascending and descending passes, however.
An orbit timed for a satellite to proceed over any given point on the landscape at roughly the same local sun time, providing repeatable sun illumination conditions during specific seasons.
A special case of the polar orbit. In a sun-synchronous orbit, the satellite passes over the same part of the Earth at roughly the same local time each day. Sun-synchronous orbits are usually meduim or low orbits.
a near-Earth orbit resembling that of a polar satellite, but inclined to it by a small angle. With the proper inclination angle, the equatorial bulge causes the orbit to rotate during the year once around the polar axis. Such a satellite then maintains a fixed position relative to the Sun and can, for instance, avoid entering the Earth's shadow.
An orbit that precesses 360° during the course of the year, permitting the satellite to obtain views of a given geographical area at the same local time each day. sun-synchronous satellite always crosses the equator on the ascending node at the same local solar time.
This article is about a class of orbits about the Earth. For a class of orbits around the sun, see heliosynchronous orbit.