About LANDSAT-TM images

LANDSAT-TM images (or scenes) cover, each one, a 185 x 185 km area, equivalent to 28 seconds of data.

The images are available in two presentations: digital, in CD-ROM, to use with a computer and software that could work with this type of information, or on paper, in color or black and white.

Each digital image comprises all 7 bands. Each band is acquired by measuring energy from the Earth's surface in a discrete frequency range of the electromagnetic spectrum from the visible to the thermal infrared - see table below.

Black and white images are made with a single band. Color images are made with 3 bands, associated to red, blue and green as requested by the customer.

Normally, we recommend the following combinations for color images:

Bands 1, 2 and 3: images in "true color", with good penetration in water, enhancing the streams, the turbidity and the sediments. The vegetation appears in greenish tonalities.

Bands 2, 3 and 4: It better defines the limits between ground and water, still keeping some details in not so deep waters and showing the differences in the vegetation that appears in red tonalities.

Bands 3, 4 and 5: It shows more clearly the limits between ground and water, with a more differentiated vegetation appearing in tonalities of green and rose.

Bands 2, 4 and 7: It shows the vegetation in green tones and allows to discriminate the humidity both in the vegetation and the ground.

Each image pixel has a spatial resolution of 30 meters (i.e., it represents a 30 meters square in the ground), with exception of band 6, which has a spatial resolution of 120 meters.

For further information on the LANDSAT-TM images, refer to:

• LANDSAT Program
• MSS LANDSAT Data
• BSRSI - Basic Science and Remote Sensing Initiative

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Last update 01Oct08