Demonstration Landsat Documentation High Performance Database Research Center

Data Characteristics

Since 1972 these satellites have provided repetitive, synoptic, global coverage of high-resolution multispectral imagery. The characteristics of the MSS and TM bands were selected to maximize their capabilities for detecting and monitoring different types of Earth resources. For example, TM band 2 can detect green reflectance from healthy vegetation, and band 3 of TM is designed for detecting chlorophyll absorption in vegetation. TM band 4 is ideal for near-IR reflectance peaks in healthy green vegetation and for detecting water-land interfaces. TM band 1 can penetrate water for bathymetric mapping along coastal areas and is useful for soil-vegetation differentiation and for distinguishing forest types. The two mid-IR red bands on TM (bands 5 and 7) are useful for vegetation and soil moisture studies, and discriminating between rock and mineral types. The thermal-IR band on TM (band 6) is designed to assist in thermal mapping, and for soil moisture and vegetation studies.

Typically, TM Bands 4, 3, and 2 can be combined to make false-color composite images where band 4 represents red, band 3, green, and band 2, blue. This band combination makes vegetation appear as shades of red, brighter reds indicating more vigorously growing vegetation. Soils with no or sparse vegetation will range from white (sands) to greens or browns depending on moisture and organic matter content. Water bodies will appear blue. Deep, clear water will be dark blue to black in color, while sediment-laden or shallow waters will appear lighter in color. Urban areas will appear blue-gray in color. Clouds and snow will be bright white. They are usually distinguishable from each other by the shadows associated with the clouds.

Spatial Resolution

A Landsat 4 and 5 TM scene has an instantaneous field of view (IFOV) of 30 square meters in bands 1 through 5 and band 7, band 6 has an IFOV of 120 square meters on the ground.
The resolution for the TM sensor is shown below:


                                   Resolution 
       Landsats 4-5                 (meters)
          Band 1                       30
          Band 2                       30
          Band 3                       30
          Band 4                       30
          Band 5                       30
          Band 6                      120
          Band 7                       30
Spectral Range

The thematic mapper (TM) is an advanced, multispectral scanning, Earth resources sensor designed to achieve higher image resolution, sharper spectral separation, improved geometric fidelity, and greater radiometric accuracy and resolution than the MSS sensor. TM data are scanned simultaneously in seven spectral bands. Band 6 scans thermal (heat) infrared radiation.

Radiometric range of bands and resolution for the TM sensor (from Landsat 4 Data Users Handbook, 1984, USGS). 

                   Wavelength        Resolution
Landsats 4-5      (micrometers)      (meters)
  Band 1            0.45-0.52          30
  Band 2            0.52-0.60          30
  Band 3            0.63-0.69          30
  Band 4            0.76-0.90          30
  Band 5            1.55-1.75          30
  Band 6           10.40-12.50        120
  Band 7            2.08-2.35          30


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