LEO > Low Earth Orbit > Polar Sun-Synchronous
Landsat 1, 2 and 3 operated in a circular, Sun-synchronous, near-polar orbit at
an altitude of approximately 913 km (567 miles), with a nominal 9:30 a.m.
crossing of the Equator during the descending ... mode. They circled the Earth
every 103 minutes, completing 14 orbits per day and viewing the entire Earth
every 18 days. The Landsat orbits are selected and trimmed so that each
satellite ground trace repeats its Earth coverage at the same local time every
day. Repetitive image centers are maintained to within 37 km (23 miles). The
orbits of Landsat 4 and 5 are repetitive, circular, Sun-synchronous, and
near-polar at a nominal altitude of 705 km (438 miles) at the Equator. The
satellites cross the Equator from north-to-south on a descending orbital node
at approximately 9:45 a.m. on each pass. Each orbit takes nearly 99 minutes,
and the spacecrafts complete just over 14 orbits each per day, covering the
entire Earth (poles excepted) every 16 days. During processing, data obtained
is framed into individual scenes of the Earth's surface. The ground
instantaneous field of view (IFOV) of the Landsat 1-3 MSS is 79m x 79m pixel
(resolution elements); the Landsat 4 and 5 MSS IFOV is 82m x 82m pixel. MSS
line scanning devices continually scan the Earth in a nominal 185 km swath
perpendicular to the Landsat orbital track. The coverage patterns result in
14-percent image sidelap at the Equator for Landsat 1-3 data; Landsat 4 and 5
image side lap at the Equator is 7.3-percent. Image sidelap percentages
increase proportionally as the latitude increases.
Taken from the NSSDC System for Information Retrieval and Storage (SIRS). For
more information contact the NSSDC Coordinated Request and User Support Office,
301-286-6695 (NASA Goddard Space Flight Center, Code 933.4, Greenbelt, Maryland
U.S. Geological Survey, 1979, Landsat Data Users Handbook, (Revised): U.S.
Geological Survey, p. 1-1 to AH-1.
U.S. Geological Survey and National Oceanic and Atmospheric Administration,
1984, Landsat 4 Data Users Handbook: U.S. Geological Survey, p. 1-1 to 5-1.
National Oceanic and Atmospheric Administration, 1986, Landsat Data Users
Notes, Number 35, 20p.