Landsat Collection 1 U.S. Analysis Ready Data

Return to Landsat U.S. ARD Overview

Access Collection 2 ARD Information

NOTE: Landsat Collection 1 U.S. ARD are no longer available to download from the USGS as of December 30, 2022. The information on this webpage is for reference only. 

Landsat Collection 1 U.S. Analysis Ready Data (ARD) products were consistently processed to the highest scientific standards and level of processing required for direct use in monitoring and assessing landscape change. Landsat Collection 1 Level-1 scenes serve as the input for generating Landsat ARD products and are available from 1972-2021.

Landsat Collection 1 (C1) U.S. ARD were available for the conterminous United States (CONUS), Alaska and Hawaii using the following Landsat Collection 1 Level-1 products:

• Landsat 8 Operational Land Imager (OLI)/ Thermal Infrared Sensor (TIRS) Tier 1, Tier 2*
• Landsat 7 Enhanced Thematic Mapper Plus (ETM+) Tier 1*
• Landsat 4-5 Thematic Mapper (TM) Tier 1

For CONUS, ARD was available from 1982-2021. The Alaska and Hawaii histograms display the available Landsat C1 Level-1 that was used for ARD products for these states. 

U.S. Landsat ARD Specifications

U.S. Landsat ARD products were generated in the Albers Equal Area (AEA) Conic map projection, processed directly from Landsat Level-1 AEA scenes through Landsat Level-2 data products using the WGS84 datum and provided in Georeferenced Tagged Image File Format (GeoTIFF). 

Landsat Collection 1 U.S. Analysis Ready Data (ARD) Projection Parameters 

Tile Grid System

U.S. Landsat ARD products were 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).  The U.S. Landsat ARD grid is anchored to the coordinates listed below. 

Landsat Collection 1 U.S. Analysis Ready Data (ARD) Tile Grid Extents

Each tile contains 5,000 x 5,000 30-meter pixels, and includes all the pixels acquired in a given day within its extents. The ARD tile pixel dimension (number of columns and rows) is smaller than the dimensions of individual Landsat acquisitions (Landsat 8: ~6300 x ~6000 pixels; Landsat 7: ~6,166 x ~5,666 pixels).  

• 422 tiles cover the land mass extent of the conterminous United States (CONUS) 
• 110 tiles cover the land mass extent of Alaska 
• 8 tiles cover the islands of Hawaii

Download Collection 1 U.S. ARD Grid Maps:           CONUS    AK     HI
Download Collection 1 U.S. ARD Grid Shapefiles:   CONUS    AK     HI

In the event an ARD tile intersects more than one row along a WRS-2 path, the northernmost row data will populate the tile from areas where rows overlap, as seen in the image below. This image shows the coverage of ARD tile h05v02 (outlined in white) compared to the WRS-2 path 44 row 27 image covering an area in central Washington state. The ARD tile also includes data from rows 26 and 28. Future versions of ARD  may implement a more sophisticated compositing scheme to populate the tile from row overlap areas.

The image below shows the coverage of ARD tile h05v02 (outlined in white) compared to the WRS-2 path 44 row 27 image covering an area in central Washington state. The ARD tile also includes data from rows 26 and 28.  (U.S. Landsat ARD Product ID: LC08_CU_005002_20130603_20170713_C01_V01; Landsat 8 Scene Product ID: LC08_L1TP_044027_20130603_20170310_01_T1).

Sources/Usage: Public Domain. View Media Details

Landsat Collection 1 U.S. ARD Products and Packaging

Landsat C1 U.S. ARD consisted of the following products, which are gridded to a common cartographic projection, and accompanied by metadata to enable further processing for the user while also retaining the traceability of data provenance:

• Top of atmosphere (TA) reflectance (reflectance calculated 'at-sensor', not atmospherically corrected)
• Top of atmosphere brightness temperature (BT) (radiance calculated 'at-sensor', not atmospherically corrected, expressed in Kelvin)
• Surface reflectance (SR) (atmospherically corrected)
• Provisional Surface Temperature (ST)
• Pixel quality assessment (QA) (common and sensor-specific quality bands included)

The definition of Landsat C1 U.S. ARD includes the products output by the following algorithms:

• Landsat 4-5 TM and Landsat 7 ETM+: Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) Surface Reflectance Algorithm (Version 3.1.2)
• Landsat 8 OLI/TIRS: Landsat Surface Reflectance Code (LaSRC) (Version 1.2.0)
• Earth Resources Observation and Science (EROS) Science Processing Architecture (ESPA) Level-2 Quality Assessment Tools: L2QA-TOOLS (Version 1.2.0)

Packaging and Filenames

Landsat C1 U.S. ARD product package and band identifiers are both derived from the Landsat 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 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 (TX) are removed from the ARD Product ID as a redundancy; the Level-1 processing date is also removed from the ARD file name.

C1 U.S. ARD products are packaged into bundles, i.e., TA reflectance, SR, and BT are delivered in separate files, each with their associated pixel quality assessment (QA) attributes. Files containing only QA bands are also provided.

C1 U.S. ARD bundles were delivered as .tar files, named according to the terms and definitions noted in Section 3 of the U.S. Landsat ARD Data Format Control Book (DFCB). A comprehensive Extensible Markup Language (XML) file containing all associated metadata is delivered with each ARD package <ARD Tile XML metadata schema>. 

Within each C1 U.S. ARD Package, a GeoTIFF (.tif) file is included for each band; these terms and definitions, as well as individual band specifications and other important information about each U.S. Landsat ARD product and QA bit index values are noted in Section 3 of the U.S. Landsat ARD Data Format Control Book (DFCB). 

The file sizes of C1 U.S. ARD products vary greatly. The table below displays the estimated average, minimum, and maximum file sizes observed in U.S. Landsat ARD products. 

U.S. Landsat ARD Caveats

Due to the structure of the U.S. Landsat ARD grid compared to the traditional Landsat path/row designations, users are encouraged to study their areas of interest to determine which tile(s) are best suited for their scientific application.

For some tiles, there may not be sufficient data to fill the tile, depending on where the path/row scene is located within the tile. The images below represent the image data and fill amounts that can be found in sample tile h26v08 in Western Pennsylvania. From left to right:  Landsat 8, May 11, 2015; Landsat 4 TM, November 25, 1982; Landsat 8, July 2, 2014; and Landsat 5 TM, March 7, 2009. 

Sources/Usage: Public Domain. View Media Details

Landsat Collection 1 U.S. ARD Known Artifacts

Interesting artifacts have been discovered in Landsat C1 U.S. ARD during science validation and analysis. The U.S. Landsat ARD Artifacts page describes each artifact, and as product research continues, any additional information will be added.

Documentation

Landsat Collection 1 U.S. ARD Data Format Control Book (DFCB)

U.S. Landsat Analysis Ready Data (ARD) Digital Object Identification (DOI): doi.org/10.5066/F7319TSJ

Citation

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

References

The following publications are included in the Remote Sensing Special Issue "Science of Landsat Analysis Ready Data":

• Egorov, A.V.; Roy, D.P.; Zhang, H.K.; Li, Z.; Yan, L.; Huang, H. Landsat 4, 5 and 7 (1982 to 2017) Analysis Ready Data (ARD) Observation Coverage over the Conterminous United States and Implications for Terrestrial Monitoring. Remote Sens. 2019, 11, 447.
• Qiu, S.; Lin, Y.; Shang, R.; Zhang, J.; Ma, L.; Zhu, Z. Making Landsat Time Series Consistent: Evaluating and Improving Landsat Analysis Ready Data. Remote Sens. 2019, 11, 51.
• Ernst, S.; Lymburner, L.; Sixsmith, J. Implications of Pixel Quality Flags on the Observation Density of a Continental Landsat Archive. Remote Sens. 2018, 10, 1570.
• Brooks, E.B.; Wynne, R.H.; Thomas, V.A. Using Window Regression to Gap-Fill Landsat ETM+ Post SLC-Off Data. Remote Sens. 2018, 10, 1502.
• Dwyer, J.L.; Roy, D.P.; Sauer, B.; Jenkerson, C.B.; Zhang, H.K.; Lymburner, L. Analysis Ready Data: Enabling Analysis of the Landsat Archive. Remote Sens. 2018, 10, 1363.
• Yan, L.; Roy, D.P. Large-Area Gap Filling of Landsat Reflectance Time Series by Spectral-Angle-Mapper Based Spatio-Temporal Similarity (SAMSTS). Remote Sens. 2018, 10, 609.
• Egorov, A.V.; Roy, D.P.; Zhang, H.K.; Hansen, M.C.; Kommareddy, A. Demonstration of Percent Tree Cover Mapping Using Landsat Analysis Ready Data (ARD) and Sensitivity with Respect to Landsat ARD Processing Level. Remote Sens. 2018, 10, 209.