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Spectral analysis: Colour glass filters (2/4)
The Thematic Mapper (TM) aboard the Landsat 5 satellite uses optical filters to take multispectral imagery.
The transmission of the TM Bands is depicted in the following graphs. For a better comparison the curves are normalised to unity.
The processing of TM images is depicted with a sample image of central Italy and the region around Rome. Geographical information and image metadata are available here.
Click on the links under the column TM band to open black-and-white images taken in the respective bands with a reduced ground resolution of 180 m in bands 1 to 7 and 90 m in band 8.
Landsat 7 Thematic Mapper bands and their characteristics
| TM band | Wavelength | Spectral range | Signal type | Ground resolution | Characteristics |
|---|---|---|---|---|---|
| 1 | 0.45-0.52 μm | blue-green | reflective | 30 m | mapping of coastal waters; discrimination of soil, vegetation and man-made features; forest classification |
| 2 | 0.52-0.60 μm | green-yellow | reflective | 30 m | classification of vegetation and man-made features |
| 3 | 0.63-0.69 μm | red | reflective | 30 m | identification of plant species and of man-made features |
| 4 | 0.76-0.90 μm | near-IR | reflective | 30 m | soil moisture measurement; discrimination of water and land |
| 5 | 1.55-1.75 μm | mid-IR | reflective | 30 m | measurement of vegetation moisture content |
| 6 | 10.40-12.50 μm | thermal IR | emissive | 60 m | measurement of earth surface temperature; identification of vegetation stress; measurement of soil moisture; cloud classification; monitoring of volcanic activity |
| 7 | 2.08-2.35 μm | mid-IR | reflective | 30 m | discrimination of rocks; measurement of soil moisture |
| 8 | 0.59-0.90 μm | panchromatic | reflective | 15 m | mapping with high geometric resolution |
