Sensors and Platforms

Landsat Thematic Mapper

The Thematic Mapper (TM) is a seven channel sensor mounted on the Landsat platform (shown above), which is maintained in a sun-synchronous, near-polar orbit at an altitude of 705 km. This provides for global repeat coverage every 16 days. TM data are recorded at 30-m ground resolution across a swath of 185 km, except for the thermal data that are recorded at 120-m ground resolution.

Band description:

1. BLUE (0.45-0.52 µm): Designed for water body penetration, making it useful for coastal water mapping. Also useful for soil/vegetation discrimination, forest type mapping and cultural feature indentification.
2. GREEN (0.52-0.60 µm): Designed to measure green reflectance peak of vegetation for vegetation discrimination and vigor assessment. Also useful for cultural feature identification.
3. RED (0.63-0.69 µm): Designed to sense in a chlorophyll absorption region aiding in plant species differentiation. Also useful for cultural feature identification.
4. NEAR INFRARED (0.76-0.90 µm): Useful for determining vegetation types, vigor, and biomass content, for delineating water bodies, and for soil moisture discrimination.
5. MID-INFRARED (1.55-1.75 µm): Indicative of vegetation moisture content and soil moisture. Also useful for differentiation of snow from clouds.
6. THERMAL INFRARED (10.4-12.5 µm): Useful in vegetation stress analysis, soil moisture discrimination, and thermal mapping applications.
7. MID-INFRARED (2.08-2.35 µm): Useful for discrimination of mineral and rock types. Also sensitive to vegetation moisture content.