The new Landsat Collection 1 inventory structure has completed processing over 5.6 million Landsat 4-5 Thematic Mapper (TM), Landsat 7 Enhanced Thematic Mapper Plus (ETM+), and Landsat 8 Operational Land Imager/ Thermal Infrared Sensor (OLI/TIRS) scenes from around the world, which are now available for download from EarthExplorer. Landsat 1-5 Multispectral Scanner (MSS) data will be processed into Landsat Collection 1 after data quality analysis and processing level investigations are complete at the end of 2017.
- Effective April 30, 2017, newly-acquired Landsat 7 ETM+ and Landsat 8 OLI/TIRS scenes are being processed into the Landsat Collection 1 inventory only; Landsat Pre-Collection inventory is no longer being populated with newly-acquired data.
- Users downloading Landsat Pre-Collection data may experience longer than expected download times.
The Landsat Pre-Collection inventory will no longer be available after October 1, 2017. Users are strongly encouraged to use only Landsat Collection 1 in their applications.
Collection 1 marks an evolutionary step in the Landsat Level-1 structure by providing a consistent archive of known data quality to support time series analysis and data “stacking,” while controlling continuous improvement of the archive and access to all data as they are acquired.
The Landsat Collection 1 definition includes three tiered categories:
- Tier 1 scenes are calibrated to the highest geometric and radiometric quality to enable data stacking for time series analysis (<12-meter geodetic accuracy).
- Tier 2 scenes do not meet the Tier 1 criteria due to significant cloud cover, insufficient ground control, and other factors.
The Real-Time Tier offers scenes immediately after acquisition using estimated parameters that are reprocessed for inclusion into Tier 1 or Tier 2 when final parameters are available. Real-time data are key for rapid response to natural and man-made disasters around the world.
Additional Landsat Collection 1 Level-1 data product changes include, new Landsat Product Identifiers (a new file naming convention), metadata changes, and the addition of new supporting files including a Quality Assurance (QA) band, solar illumination and sensor view angle coefficients, land-based cloud cover scores, and new life-long gain adjustments for Landsat 4-5 TM sensors.