The satellite revisit period is the time elapsed between observations of the same point on Earth by a
satellite. It depends on the satellite's
orbit, target location, and swath of the sensor.
"Revisit" is related to the same
ground trace
A ground track or ground trace is the path on the surface of a planet directly below an aircraft's or satellite's trajectory. In the case of satellites, it is also known as a suborbital track, and is the vertical projection of the satellite's or ...
, a projection of the satellite's orbit on to the Earth. Revisit requires a very close repeat of the ground trace. In the case of
polar orbit or
highly inclined low Earth orbit reconnaissance satellite
A reconnaissance satellite or intelligence satellite (commonly, although unofficially, referred to as a spy satellite) is an Earth observation satellite or communications satellite deployed for military or intelligence applications.
The ...
s, the sensor must have the variable swath, to look longitudinally (east-west, or sideways) at a target, in addition to direct overflight observation, looking
nadir.
In the case of the
Israeli
EROS Earth observation satellite, the ground trace repeat is 15 days, but the actual revisit time is 3 days, because of the swath ability of the camera payload.
See also
*
Orbit period
*
Satellite watching, spotting satellites in the sky as they pass
References
{{DEFAULTSORT:Satellite Revisit
Satellites
Orbits