Landsat Collection 1 consists of Level-1 data products from 1972-2021 and are generated from Landsat 8 Operational Land Imager (OLI)/Thermal Infrared Sensor (TIRS), Landsat 7 Enhanced Thematic Mapper Plus (ETM+), Landsat 4-5 Thematic Mapper (TM)*, and Landsat 1-5 Multispectral Scanner (MSS) instruments.
The implementation of Collections represents a significant change in the management of the Landsat Archive by ensuring consistent quality through time and across instruments, along with additional changes like metadata and file names.
* Some Landsat 4-5 Thematic Mapper (TM) data acquired between 1984 and 1989 cannot be processed by the USGS Landsat Product Generation System and added to the Collection 1 Level-1 inventory. Visit the Landsat Processing Systems page for more information about these specific scenes.
Landsat Science Products inherit characteristics of the Landsat Collection 1 Level-1 data products. The algorithms used for Collection 1 Landsat Science Products are listed below.
- Land Surface Reflectance (LaSRC): Version 1.3.0
- Landsat 4-7 Surface Reflectance (LEDAPS): Version 3.2.1
- Landsat 4-8 Provisional Surface Temperature (ST): Version 1.3.0
- Landsat Dynamic Surface Water Extent (DSWE): Version 2.3.0
- Landsat Fractional Snow Covered Area (fSCA): Version 1.2.0
- Landsat Burned Area (BA): Version 1.2.0
PLEASE NOTE: Landsat Collection 1 based forward processing ceased on December 31, 2021. Starting January 1, 2022, all new Landsat acquisitions are processed into the Collection 2 inventory structure only.
Due to advancements in data processing and algorithm development, users are discouraged from using Collection 1 and Collection 2 interchangeably within the same workflow.
Collection 1 products will remain available for search and download through December 31, 2022.
Collection 1 Tiers
Landsat Collection Tiers are the inventory structure for Level-1 data products and are based on data quality and level of processing. The tier definition purpose is to support easier identification of suitable scenes for time-series pixel-level analysis, and provide temporary data that are processed immediately upon downlink to be dispensed quickly in emergency response situations with limited calibration.
Newly-acquired Landsat 7 ETM+ and Landsat 8 OLI/TIRS data are processed upon downlink but use predicted ephemeris (Landsat 7), initial bumper mode parameters (Landsat 7), or initial TIRS line-of-sight model parameters (Landsat 8). The data is placed in the Real-Time tier and made available for download in less than 12 hours (4-6 hours typically). Once the data have been reprocessed with definitive ephemeris, updated bumper mode parameters and refined TIRS parameters, the products are transitioned to either Tier 1 or Tier 2 and removed from the Real-Time tier. The transition delay from Real-Time to Tier 1 or Tier 2 is between 14 and 26 days. Follow-on processing details are described below.
- Landsat 7 ETM+ acquisitions are processed immediately using predicted ephemeris and initial bumper mode parameters and placed into the Real-Time tier. Shortly after initial processing (about 1 day), the data are reprocessed using definitive ephemeris, but remain in the Real-Time tier. During a period of instrument trending/characterization (about 26 days), calibration parameter adjustments finalize the geometric correction model, and the data are reprocessed and placed into either Tier 1 or Tier 2.
- Landsat 8 TIRS data may not meet specifications for co-registration with OLI. TIRS line-of-sight model parameters are refined based on data acquired during biweekly calibration maneuvers and scenes are reprocessed within 14 to 16 days of acquisition and placed into either Tier 1 or Tier 2.
Tier 1 (T1)
Landsat scenes with the highest available data quality are placed into Tier 1 and are considered suitable for time-series analysis. Tier 1 includes Level-1 Precision and Terrain (L1TP) corrected data that have well-characterized radiometry and are inter-calibrated across the different Landsat instruments. The georegistration of Tier 1 scenes is consistent and within prescribed image-to-image tolerances of ≦ 12-meter radial root mean square error (RMSE).
Tier 2 (T2)
Landsat scenes not meeting Tier 1 criteria during processing are assigned to Tier 2. Tier 2 scenes adhere to the same radiometric standard as Tier 1 scenes, but do not meet the Tier 1 geometry specification due to less accurate orbital information (specific to older Landsat sensors), significant cloud cover, insufficient ground control, or other factors. This includes Systematic Terrain (L1GT) and Systematic (L1GS) processed data. Users interested in Tier 2 scenes can query the RMSE and other properties to determine their application suitability.
The Tier designation (T1, T2, RT) is visible at the end of the Landsat Product Identifier, as shown in the examples below. It is also provided as an additional metadata field in EarthExplorer. Note: Historical Landsat 4-5 TM and Landsat 7 ETM+ data received from International Ground Stations supporting the Landsat Global Archive Consolidation effort are placed in either Tier 1 or Tier 2 after Collection 1 processing.
Tier 1: LE07_L1TP_016039_20040918_20160211_01_T1
Tier 2: LT04_L1GS_017036_19821115_20160315_01_T2
Collection 1 Product Identifiers
Landsat Collection 1 product identifiers include the Collection processing levels, processing date, Collection number, and Collection tier category.
The legacy Landsat scene ID that was used before Collection 1 processing remains visible for each scene on EarthExplorer metadata pages, as well as in the metadata file (MTL.txt) that is delivered with the Level-1 data product. It can also be entered onto the the EarthExplorer Additional Criteria tab when conducting searches.
Changes Applied During Collection 1 Processing
Along with the Landsat Product Identifier, Collection 1 processing created addtional files to Level-1 products, and also added important fields to the metadata file. In addition, a new cloud cover algorithm was applied to Collection 1 Level-1 data.
New Files included in Collection 1 Level-1 data products
Quality Assessment (QA) bands (NEW to Landsat 1-5 MSS, Landsat 4-5 TM and Landsat 7 ETM+; UPDATED for Landsat 8 OLI/TIRS)
Solar Illumination and Sensor Viewing Angle Coefficient Files (Landsat 4-5 TM, Landsat 7 ETM+, and Landsat 8 OLI/TIRS)
Additional Metadata (MTL.txt) fields
The Saturation Bits parameter identifies which bands contain saturated pixels (Landsat 4-5 TM, Landsat 7 ETM+, Landsat 8 OLI/TIRS)
Land cloud cover assessment estimates the percent of the land in a scene that is covered by clouds (Landsat 4-7)
New Cloud Cover Algorithm
The C Function of Mask (CFMask) algorithm identifies fill, cloud, cloud confidence, cloud shadow, and snow/ice in Landsat 4-5, Landsat 7, and Landsat 8 scenes for representation in the Quality Assessment (QA) band.
Specific for Landsat 8 OLI/TIRS
In February 2017 an algorithm was developed and implemented into the Landsat Product Generation System (LPGS) to correct for the Thermal Infrared Sensor (TIRS) stray light issue and reduced radiance errors. Landsat 8 Data Users Handbook (Appendix A) provides details about the issue and resolution. Users may also find the following journal articles useful about this topic:
Specific for Landsat 4-5 TM
"No-Payload Correction Data (PCD)" scenes. Over 260,000 Landsat 5 TM scenes acquired between January 1986 and December 1999, originally downlinked to international ground stations, lack the necessary PCD. Until recently, these scenes failed Landsat Level-1 data processing and could not be added to the Landsat data inventory. However, recent processing algorithm changes made it possible to process the majority of these scenes into the Landsat Collection 1 data inventory and make them available for download.
Landsat Geometric Verify Image and Report files are provided in Landsat 4-5 TM Collection 1 Tier 1 data products. These files help determine the geometric accuracy of each TM precision and terrain-corrected scene and contain summary statistics while listing all verification points.
Specific for Landsat 1-5 MSS
Landsat 1-5 MSS data have historically proved challenging to Landsat Level-1 processing systems. Many MSS scenes have missing scan lines and other anomalies and artifacts.
A number of MSS scenes from 1977 and 1978, (as well as all MSS 5 data acquired from 1995 to 1999 and 2012- 2013) do not contain data in all four band files delivered in the Level-1 product (see this file for a list of scenes with missing data).
Landsat Geometric Verify Image and Report files are provided in Landsat 1-5 MSS)Collection 1 Tier 1 data products. These files help determine the geometric accuracy of each MSS precision and terrain-corrected scene and contain summary statistics while listing all verification points.
The effort to process Landsat MSS data into Collection 1 required data processing changes to influence the geometric and radiometric accuracy of the Level-1 data products. The Landsat Collection 1 Multispectral Scanner Data Processing page provides in-depth information about the work done to successfully process Landsat MSS data into the Collection 1 archive.
Processing Level Designation Changes
The table below displays the Landsat Collection 1 Level-1 processing levels.
|Terrain Precision Correction
|Radiometrically calibrated and orthorectified using ground control points (GCPs) and digital elevation model (DEM) data to correct for relief displacement.The highest quality Level-1 products suitable for pixel-level time series analysis.
GCPs used for L1TP correction are derived from the Global Land Survey 2000 (GLS2000) data set.
Landsat processing DEM sources include:
|Systematic Terrain Correction
|Radiometrically calibrated with systematic geometric corrections applied using the spacecraft ephemeris data and DEM data to correct for relief displacement.
Note: L1GT are the highest level of radiometric calibration and systematic correction possible for Landsat 7 and Landsat 8 scenes collected over Antarctica. The L1GT product uses the high-resolution Radarsat Antarctic Mapping Project (RAMP) Version 2 as the elevation correction source.
|Geometric Systematic Correction
|Radiometrically calibration with only systematic geometric corrections applied using the spacecraft ephemeris data|
*The ‘NED’ terminology has been retired. The layers previously referred to as NED are now branded as 3DEP seamless DEMs, which are offered in the broader suite of 3DEP elevation products and available from The National Map.
All Landsat 1-8 Collection 1 Level-1 are produced by the Landsat Product Generation System (LPGS) using the following parameters:
- Georeferenced Tagged Image File Format (GeoTIFF)
- Cubic convolution (CC)
- Universal Transverse Mercator (UTM) map projection (Stereographic is used for scenes with a center latitude greater than or equal to -63.0 degrees)
- World Geodetic System (WGS) 84 datum
MAP (North-up) image orientation
Landsat Level-1 data are distributed as scaled and calibrated digital numbers (DN). The DN’s can be scaled to absolutely calibrated radiance or reflectance values using metadata which are distributed with the product. Formulas and information on converting Level-1 data to Top-of-Atmosphere radiance, reflectance, or brightness temperature can be found on the Using the USGS Landsat Level-1 Data Product page.
The Landsat Geometry webpage provides additional information on the Landsat Level-1 processing levels, and includes details about GCP updates, DEM, and PCD.
Calibration Parameter File (CPF) Name Changes
Calibration Parameter Files (CPF) provide radiometric and geometric coefficients needed for processing of raw, uncorrected Landsat image data. Each timeframe specific CPF contains calibration coefficients that have been adjusted to correct for the time varying performance of the sensor.
Response Linearization Look Up Tables (RLUT) Name Changes (Landsat 8 only)
Response Linearization Look Up Tables (RLUT) are additional files that accompany Calibration Parameter Files (CPF) and contain a mapping look up table to linearize the output of the OLI and TIRS detectors.
Landsat Collection 1 Level-1 data are available for download from EarthExplorer or GloVis. On EarthExplorer, the data are located under the Landsat category, Landsat Collection 1 Level-1 subcategory, and listed as Landsat 8, Landsat 7, Landsat 4-5 TM, and Landsat 1-5 MSS datasets.
The EarthExplorer "Additional Criteria" tab for each Collection 1 dataset allows users to select parameters for each Landsat sensor (i.e., Landsat 7 SLC-on/SLC-off, T1/T2/RT, or RMSE range).