The document discusses two Earth observation sensors used in the Landsat program: the Thematic Mapper (TM) and the Enhanced Thematic Mapper Plus (ETM+). The TM collects 7 bands of multi-spectral image data at 30m resolution, except for one thermal band. The ETM+ is similar but with improved resolution of the thermal band and addition of a panchromatic band. Both sensors orbit non-synchronously at 705km with a 16 day revisit cycle and 185km swath width.

1. Sensors and Their Specifications
Thematic Mapper (TM)
A Thematic Mapper (TM) is one of the Earth observing sensors introduced
in the Landsat program. The first was placed aboard Landsat
4 (decommissioned in 2001), and another was operational aboard Landsat
5 up to 2012. TM sensors feature seven bands of image data (three in
visible wavelengths, four in infrared) most of which have 30 meter spatial
resolution. TM is a whisk broom scanner which takes multi-spectral
images across its ground track. It does not directly produce a thematic map.
The Thematic Mapper has become a useful tool in the study of albedo and
its relationship to global warming and climate change.
Band Specification
Band Wavelength Resolution Swath Revisit time
(µm) (m) Width (days)
(km)
Band 1 (Blue) 0.45 to 0.52 30 185 16
Band 2 (Gr) 0.52 to 0.6 30 185 16
Band 3 (Red) 0.63 to 0.69 30 185 16
Band 4 (NIR) 0.76 to 0.9 30 185 16
Band 5 (SWIR) 1.55 to 1.75 30 185 16
Band 6 (TIR) 10.4 to 12.5 120 185 16
Band 7 2.08 to 2.35
30 185 16
(SWIR)
S K Diwakar

2. Sensors and Their Specifications
Enhanced Thematic Mapper (ETM+)
ETM+ is similar to TM, but has a higher spatial resolution thermal channel
and includes a new panchromatic channel. These satellites have a polar,
circular, sun-synchronous 705-km orbit with a 16-day repeat cycle. The TM
swath width is 185 km.
Band Specification
Band Wavelength Region (µm) Resolution (m)
1 0.450-0.515 (blue) 30
2 0.525-0.605 (green) 30
3 0.630-0.690 (red) 30
4 0.750-0.900 (near-IR) 30
5 1.55-1.75 (mid-IR) 30
6 10.4-12.5 (thermal-IR) 60
7 2.08-2.35 (mid-IR) 30
PAN 0.52-0.90 15
S K Diwakar