Landsat Collection 2 U.S. Analysis Ready Data
Landsat Collection 2 U.S. Analysis Ready Data (ARD) are consistently processed to the highest scientific standards and level of processing required for direct use in monitoring and assessing landscape change. Landsat Collection 2 Level-1 data that are processed into Albers-projected Level-2 Surface Reflectance and Surface Temperature serve as inputs for generating U.S. ARD.
What's New in Collection 2?
This file displays the details and highlights changes made to Landsat Collection 2 Level-1 and Level-2 products, including U.S. ARD, compared to Collection 1.
Conversion Tool
The U.S. Landsat Analysis Ready Data Tile Conversion Tool converts a single Landsat WRS-2 path / row or latitude/longitude coordinates into the corresponding Landsat ARD tile.
Return to Landsat U.S. ARD Overview
Landsat Collection 2 (C2) was released in 2020 and provides several improvements to Landsat Level-1 data, including better geometric accuracy, which increases the number of C2 U.S. ARD tiles that are available. Visit the Landsat Collection 2 page for more details about these improvements.
Landsat C2 U.S. ARD significantly reduces the magnitude of data processing for application scientists, who currently have to download and prepare large amounts of Landsat scene-based data for time-series investigative analysis.
Landsat C2 U.S. ARD are available for the conterminous United States (CONUS) (1982-present), Alaska (1984-present) and Hawaii (1989-1993 and 1999-present) using Landsat C2 Level-1 data processed into Albers-projected Level-2 Surface Reflectance and Surface Temperature products from the following Landsat sensors:
- Landsat 8/9 Operational Land Imager 2 (OLI-2)/ Thermal Infrared Sensor 2 (TIRS-2) Tier 1, Tier 2 *
- Landsat 7 Enhanced Thematic Mapper Plus (ETM+) Tier 1
- Landsat 4-5 Thematic Mapper (TM) Tier 1
The CONUS, Alaska, and Hawaii histograms display the available Landsat Collection 2 data used to create ARD products for these states.
Landsat 8 and Landsat 9 U.S. ARD are created 2 to 3 days after the tiered Level-1 products are processed to Level-2 science products. Visit the Landsat Collection 2 Generation Timeline for more details about data processing timelines.
Landsat 1-5 Multispectral Scanner (MSS) data will be considered for processing into the U.S. ARD inventory once these data have been sufficiently analyzed for their suitability.
Global ARD specifications are being developed by the USGS/NASA Landsat Team. Additional information will be provided when details become available.
Landsat Collection 2 U.S. ARD Tile Grid System
Landsat C2 U.S. ARD products are processed to a common tiling scheme, which is modified from the Web-Enabled Landsat Data (WELD) system developed at South Dakota State University (SDSU) (Roy and others, 2010).
U.S. ARD is packaged in tiles, which are units of uniform dimension bounded by static corner points in a defined grid system. An ARD tile is defined as 5,000 x 5,000 30-m pixels. For a given acquisition date, an ARD tile can be created from 1 to 3 scenes acquired over the same WRS-2 path.
NOTE: The Alaska tile grid (shown right) has been modified for C2 2 U.S. ARD to include the Aleutian Islands. The CONUS and Hawaii tile grids remain the same in Collection 2 as they are in Collection 1.
Shapefiles of Landsat Collection 2 ARD tile grids are available to download:
Landsat Collection 2 U.S. ARD Product Contents
The following products are included in Landsat C2 U.S. ARD:
- Top of Atmosphere (TOA) Reflectance
- TOA Brightness Temperature (BT)*: both TOA Reflectance and TOA BT are generated using the calibration parameters from the metadata.
- Surface Reflectance (SR)^: Generated using the specified algorithm which applies the atmospheric correction routines on the TOA Reflectance.
- For OLI/TIRS: USGS Land Surface Reflectance Code (LaSRC) version 1.5.0 (derived from NASA LaSRC version 3.5.5)
- For TM and ETM+: USGS Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) Surface Reflectance algorithm version 3.4.0 (derived from the February 2011 version of NASA LEDAPS code)
- Surface Temperature (ST)*^: calculated by applying the Single Channel algorithm on TIRS Band 10, and TM/ETM+ Band 6. (Note: ST is available only when L2SP exist) generated using Landsat Level 2 Surface Temperature algorithm version 1.3.0 (derived from June 2017 version of RIT ST code)
- Quality Assessment (QA) bands: Pixel Quality Assessment derived from Fmask version 3.3.1; Aerosol and Cloud QA derived from atmospheric compensation algorithms, radiometric saturation QA derived from detector's input signal level.
- Extensible Markup Language (XML) metadata: contains associated metadata for tile. <C2 U.S. ARD Tile XML metadata schema>.
- JavaScript Object Notation (JSON) metadata: contains associated metadata for tile written in JSON.<C2 U.S. ARD Tile JSON schema>
*For Landsat 7 ETM+ products, Band 6 TOA BT and ST data are generated from ETM+ Band 6 High (6H) and 6 Low (6L) merged together. The merged band contains unsaturated pixels from Band 6H. If Band 6H pixels have a BT outside of the 6H dynamic range (240 to 322 Kelvin) then 6L band pixels are used. Pixels that are saturated in Band 6L remain saturated in the merged Band 6 product. The merged thermal radiance is then used in the creation of the TOA BT and ST data.
^Landsat C2 U.S. ARD Level-2 Science Products are generated using Landsat Product Generation System (LPGS) version 15.4.0c. The LPGS software includes a new Quality Assessment (QA) Application that provides consistent per-pixel QA in Level 1 and Level 2 product packages. The QA Application uses the outputs of C version of Function of Mask (CFMask) version 3.3.1 (derived from Fmask version 3.3.1) to detect cloud, water, and snow.
Note: 15-meter panchromatic bands (OLI/ ETM+ Band 8) are not processed to TOA or Surface Reflectance.
Please refer to the Landsat Collection 2 U.S. ARD Data Format Control Book (DFCB) to view valid ranges, scaling factor, and other important specifications for each band included in Landsat Collection 2 U.S. ARD.
Product Packaging and Filenames
Landsat C2 U.S. ARD product package and band identifiers are both derived from the ARD Product ID. While the ARD Product ID follows the naming convention of its collection-based data source to the best extent possible, the ARD Product ID replaces WRS-2 path and row designations with tile identifiers (i.e., HHH horizontal and VVV vertical), as an ARD tile may include data from overlapping rows. Processing level (LLLL) and collection category (XX) are removed from the ARD Product ID as a redundancy; the Level-2 processing date is also removed from the ARD file name.
Landsat Collection 2 U.S. ARD files are stored in Cloud Optimized Georeferenced Tagged Image File Format (GeoTIFF) (COG). The COG file format is an extension of the GeoTIFF file format which enables more flexible access to Geospatial data. For additional information about the COG format please refer to Landsat Cloud Optimized GeoTIFF Data Format Control Book.
Data Access
Visit the Landsat Data Access web page to discover how to search and download all Landsat products from USGS data portals. The USGS Landsat no-cost open access data policy remains intact since its inception in 2008.
Known Artifacts
During product analysis and user feedback, some caveats and artifacts were identified in Landsat C2 U.S. ARD products; while these issues do not significantly impact the scientific integrity of ARD products, the Landsat U.S. ARD Artifacts page provides details about each known artifact.
Landsat Collection 2 Reprocessing Events
Occasionally, select Landsat scenes must be reprocessed. Please visit the Collection 2 Reprocessing Events web page to learn more about what scenes have been reprocessed.
Documentation
Landsat Collection 2 U.S. ARD Data Format Control Book (DFCB)
Landsat Calibration and Validation (CalVal) Algorithm Description Document (ADD) — Landsat 8 LaSRC algorithm information (Section 4.7.4) and Single Channel Surface Temperature algorithm information (Section 4.7.5)
Landsat 8 Collection 2 Level 2 Science Product Guide
LEDAPS Calibration and Validation (CalVal) Algorithm Description Document (ADD) — Landsat 4-7 LEDAPS algorithm information
Landsat 4-7 Collection 2 Level 2 Science Product Guide
Citation Information
There are no restrictions on the use of Landsat Collection 2 Analysis Ready Data (ARD) Products. It is not a requirement of data use, but the following citation may be used in publication or presentation materials to acknowledge the USGS as a data source and to credit the original research:
Landsat Collection 2 Analysis Ready Data (ARD) Product courtesy of the U.S. Geological Survey. Digital Object Identifier https://doi.org/10.5066/P960F8OC.
Dwyer, J.L., Roy, D.P., Sauer, B., Jenkerson, C.B., Zhang, H., and Lymburner, L., 2018, Analysis ready data—Enabling analysis of the Landsat archive: Remote Sensing, v. 10, no. 9, art. no. 1363. doi.org/10.3390/rs10091363.