Space Oblique Mercator

Description

This projection is nearly conformal and has little scale distortion within the sensing range of an orbiting mapping satellite, such as Landsat. This is the first projection to incorporate the earth's rotation with respect to the orbiting satellite. For Landsat 1, 2, and 3, the path range is from 1 to 251. For Landsat 4 and 5, the path range is from 1 to 233.

Projection method

Modified cylindrical, for which the central line is curved and defined by the ground track of the orbit of the satellite.

Line of tangency

Conceptual.

Linear graticules

None.

Properties

Shape

Shape is correct within a few parts per million for the sensing range of the satellite.

Area

Varies by less than 0.02 percent for the sensing range of the satellite.

Direction

Minimal distortion within the sensing range.

Distance

Scale is true along the ground track and varies approximately 0.01 percent within the sensing range.

Limitations

Plots for adjacent paths do not match without transformation.

Uses and applications

Specifically designed to minimize distortion within the sensing range of a mapping satellite as it orbits the rotating earth.

Used to tie satellite imagery to a ground-based planar coordinate system and for continuous mapping of satellite imagery.

Standard format used for data from Landsat 4 and 5.

Parameters

Workstation

• Landsat vehicle ID (1, 2, 3, 4, 5)
• Orbital path number (1–233)