Enhanced Thematic Mapper (ETM)
Previous to the availability of free Landsat data, Level 1G scenes were provided for EOS Land Validation Core Sites, with an emphasis on those locations and dates where related field and/or tower data were being collected. The 15m spatial resolution of the panchromatic band in ETM+ and the 30m resolution of the multi-spectral bands are used to scale the field and tower data to the 250m, 500m, and 1km MODIS pixels.
Information on conversion of the Level 1G data to either radiance or reflectance can be found in Chapter 11 of the Landsat 7 Science Data User's Handbook. The required calibration parameter files are available through EDC.
Some of the Landsat 7 ETM+ data have been ordered in HDF format. While these files can be read into a software that can read HDF, they can also be read as generic binary: see instructions.
Thematic Mapper (TM)
The fifth in a series of Earth observation platforms funded by the US Government, launch of Landsat 5 continued the Thematic Mapper archive that began in 1982.
Systematically Corrected Landsat 5 TM products are available for some of the EOS Land Validation Core Sites. Landsat data are available from the EarthExplorer web site.