Landsat Collection 2 U.S. Analysis Ready Data: Tiled Landsat for Time Series

The U.S. Analysis Ready Data tile grid for the conterminous United States, and a stack of images of one tile from different dates (h, horizontal; v, vertical). USGS graphic.

What it is

Landsat Collection 2 U.S. Analysis Ready Data (U.S. ARD) are bundles of tiled Landsat data that make the archive easier to analyze and cut the time users spend processing data for time-series analysis.

Collection 2, released in 2020, improves on Collection 1 — including better geometric accuracy, which increases the number of tiles available — and is processed to the highest scientific standards.

Coverage

The tiles are built from Collection 2 Level-1 data, processed into Level-2 surface reflectance and surface temperature products in the Albers Equal-Area Conic projection, from these sensors:

• Landsats 8 and 9 — Operational Land Imager and Thermal Infrared Sensor: tier 1 and tier 2;
• Landsat 7 — Enhanced Thematic Mapper Plus: tier 1;
• Landsats 4 and 5 — Thematic Mapper: tier 1.

The tile grid

• The scheme: a common tiling scheme adapted from the Web-Enabled Landsat Data system developed at South Dakota State University — tiles of uniform size bounded by fixed corner points in a defined grid.
• Size: each tile is 5,000 × 5,000 pixels of 30 meters.
• Sources: for a given date, a tile is built from one to three scenes acquired along the same World Reference System-2 path.
• Names: product identifiers replace path and row with tile numbers — HHH for horizontal and VVV for vertical — because a tile may draw on several rows.
• Changes: for Collection 2, the Alaska grid was extended to take in the Aleutian Islands; the conterminous U.S. and Hawaii grids are unchanged.

How one tile (CUH006V005, covering Boise and part of the Boise National Forest) relates to two Landsat 9 scenes of October 5, 2022. Tiles have varying data fill, depending on how they meet a date's scenes. USGS graphic.

What's in each tile

• Top of atmosphere reflectance and brightness temperature, generated with the calibration parameters in the metadata.
• Surface reflectance: atmospheric correction applied to top-of-atmosphere reflectance — with the USGS LaSRC code, version 1.5.0 (derived from NASA's LaSRC 3.5.5), for Operational Land Imager and Thermal Infrared Sensor data, and LEDAPS, version 3.4.0 (from NASA's February 2011 code), for Thematic Mapper and Enhanced Thematic Mapper Plus data. The 15-meter panchromatic band (band 8) isn't processed.
• Surface temperature: the Single Channel algorithm applied to thermal band 10 (TIRS) or band 6 (TM/ETM+), available only where the Level-2 product exists — algorithm version 1.3.0, from the Rochester Institute of Technology's June 2017 code.
• Quality assessment bands: pixel QA from Fmask 3.3.1; aerosol and cloud QA from the atmospheric compensation algorithms; and radiometric saturation QA from the detector's input signal.
• Metadata in XML and JSON.

Getting the data

USGS Landsat data have been free and open since 2008. Landsat Data Access explains how to search for and download every Landsat product, and the product page has the product guide and the algorithm description.

Using and citing it

Use is not restricted. Citing is optional; the USGS suggests "Landsat Collection 2 U.S. Analysis Ready Data product courtesy of the U.S. Geological Survey," along with Dwyer and others (2018), "Analysis Ready Data—Enabling analysis of the Landsat archive," Remote Sensing 10(9): 1363.

Sources

Based on U.S. Geological Survey, "Landsat Collection 2 U.S. Analysis Ready Data," Fact Sheet 2023–3015, April 2023, USGS; a work of the United States government in the public domain. The figures are restored from the fact sheet's PDF.