The TM Thread
The Thematic Mapper (TM) sensor was first active on board the Landsat 4 satellite, launched on 16 July 1982, which was decommissioned on 15 June 2001. It was also on the Landsat 5 satellite, launched on 1 March 1984, which was decommissioned in 2013.
The Thematic Mapper is a multi-spectral system consisting of 7 bands. Band 1 detected visible blue/green (in contrast to Landsat 1-3 whose MSS system only detected down to 0.5 microns), with a wavelength range of 0.45 - 0.52 microns; Band 2 detected visible green, with wavelength range of 0.52 - 0.61 microns; Band 3 detected visible red, with a wavelength range of 0.63 - 0.69 microns. Band 4 roughly consolidated the two near-infrared bands of the MSS system into a single near IR band spanning 0.76 to 0.90 microns. Bands 5 introduced a mid-infrared band with a range of 1.55 to 1.75 microns, and Band 6 introduced a band for detecting thermal radiation, with a range of 10.40 to 12.50 microns. Band 7, a second mid-IR band, was tacked on later, to help map arid landscapes and mineral deposits, and covers 2.08 to 2.35 microns.
The spatial resolution of each band was a pixel size of 30 m, except for the thermal band which had a pixel size of 120 m. Data were quantized in 8-bit radiometric resolution. The satellites were set to an orbit that would produce a 16-day repeat observation cycle for each point on earth except the areas around the poles (near-polar orbit), and would always observe the same point with the same angle relative to the sun (sun-synchronous), using a nadir perspective.
Landsat 6, which was not successfully launched, would have carried an Enhanced Thematic Mapper (ETM), which added a Band 8 for panchromatic data, covering a range of 0.52 to 0.90 microns, with a spatial resolution of 15 meters. Landsat 7, which was launched on 15 April 1999, carried the Enhanced Thematic Mapper Plus (ETM+), which has the panchromatic 8th band, and also changes Band 6 (thermal) into a high and low gain bands with 60 m spatial resolution. Landsat 7's data, however, has been affected since 31 May 2003 by the malfunction of the Scan Line Corrector, which has caused about a fifth of the data from each Landsat scene to be lost, in a backgammon-board-like pattern; the data has still found some use, but many users preferred Landsat 5 data, which did not have this problem.
The Thematic Mapper is a multi-spectral system consisting of 7 bands. Band 1 detected visible blue/green (in contrast to Landsat 1-3 whose MSS system only detected down to 0.5 microns), with a wavelength range of 0.45 - 0.52 microns; Band 2 detected visible green, with wavelength range of 0.52 - 0.61 microns; Band 3 detected visible red, with a wavelength range of 0.63 - 0.69 microns. Band 4 roughly consolidated the two near-infrared bands of the MSS system into a single near IR band spanning 0.76 to 0.90 microns. Bands 5 introduced a mid-infrared band with a range of 1.55 to 1.75 microns, and Band 6 introduced a band for detecting thermal radiation, with a range of 10.40 to 12.50 microns. Band 7, a second mid-IR band, was tacked on later, to help map arid landscapes and mineral deposits, and covers 2.08 to 2.35 microns.
The spatial resolution of each band was a pixel size of 30 m, except for the thermal band which had a pixel size of 120 m. Data were quantized in 8-bit radiometric resolution. The satellites were set to an orbit that would produce a 16-day repeat observation cycle for each point on earth except the areas around the poles (near-polar orbit), and would always observe the same point with the same angle relative to the sun (sun-synchronous), using a nadir perspective.
Landsat 6, which was not successfully launched, would have carried an Enhanced Thematic Mapper (ETM), which added a Band 8 for panchromatic data, covering a range of 0.52 to 0.90 microns, with a spatial resolution of 15 meters. Landsat 7, which was launched on 15 April 1999, carried the Enhanced Thematic Mapper Plus (ETM+), which has the panchromatic 8th band, and also changes Band 6 (thermal) into a high and low gain bands with 60 m spatial resolution. Landsat 7's data, however, has been affected since 31 May 2003 by the malfunction of the Scan Line Corrector, which has caused about a fifth of the data from each Landsat scene to be lost, in a backgammon-board-like pattern; the data has still found some use, but many users preferred Landsat 5 data, which did not have this problem.
Tagged:
Howdy, Stranger!
It looks like you're new here. If you want to get involved, click one of these buttons!
Comments