MRLC 2001 Terrain Corrected Dataset Description

The Multi-Resolution Land Characteristics (MRLC) Consortium was originally formed in 1992 in order to meet the needs of several federal agencies (USGS, EPA, NOAA, and USFS) for Landsat 5 imagery, and land-cover information. The on-going need for current Landsat 7 data, land-cover and other geospatial data within the federal government culminated in reforming the MRLC Consortium in 2001 (called MRLC 2001).

The MRLC 2001 strategy includes:

1. acquisition of a multi-temporal Landsat 7 TM data centered around the year 2001 that includes three dates of imagery per path-row;
2. preprocessing of these data using common methods and standards, and;
3. generation of a consistent national land-cover data base.

The MRLC members recommend that the National land cover data assessment be coincident with the decadal national population census.

Data from Landsat 7 (launch successfully on April 15, 1999) is being primarily used for MRLC 2001. Landsat 7 data have 3 significant radiometric improvements over Landsat 5. The first is inclusion of a 15-meter resolution panchromatic (pan) band. Second, resolution of the thermal band (1040 - 1250 nm) will be improved from 120 to 60 meters. Third, the instrument artifacts that caused striping patterns in Landsat 4 and 5 data are removed up-front in Landsat 7 data using rigorous radiometric calibration procedures. Some Landsat 5 data are included in the MRLC archive to augment the Landsat 7 coverage.

MRLC 2001 pre-processing specifications include:

1. a minimum of three dates per path/row (representing different seasonality) for the conterminous lower 48 US states, Alaska, Hawaii and Puerto Rico;
2. geometric terrain-corrected registration to within one pixel spatial accuracy;
3. data referenced to the National Albers Equal map projection;
4. imagery re-sampled using cubic convolution to 30m pixels, and;
5. all 8 TM bands processed (including thermal and pan bands) for Landsat 7 data.

Access to the Landsat 7 scenes purchased by the MRLC 2001 can be found at the Glovis website (http://glovis.usgs.gov), set Selecting Collection to Landsat Science, then choose either NLCD/MTBS Radiance or NLCD/MTBS Reflectance to select the available scenes. These data may also be accessed by using the query tools at the MRLC Scene Library (http://www.mrlc.gov/download_data.php) webpage.

For additional information contact: