Individual image band and metadata files are standard in all Landsat Collection 1 Level-1 data products. Each data product also includes additional ancillary files for scientific use.
The table below displays the number of files that are included in Landsat Collection 1 Level-1 data products for each sensor, and descriptions about each of the files are below.
NOTE: Adding new files creates a larger Level-1 data product. See this FAQ for a comparison of file sizes between Pre-Collection and Collection 1 data products.
Image Files (_B1.TIF): Each image data file contains the spectral response information collected by the image sensor over a specified band (channel), or range of spectral wavelengths. The number of image band files and ground resolution (pixel size) will vary according to sensor. The spectral ranges and ground resolution covered by each band can be found on the Band Designation Web page.
Quality Assessment Band File (_BQA.TIF): The Quality Assessment (QA) band is an informational file that contains values assigned during Collection 1 processing to represent interpreted surface, atmosphere, and sensor conditions that can affect the overall usefulness of a given pixel within a scene. Used effectively, QA bits improve the integrity of science investigations by indicating which pixels might be affected by instrument artifacts or cloud contamination.
Angle Coefficient File (_ANG.txt): The Angle Coefficient File provides information that can be used by scientific users to compute the solar and sensor viewing angle on a per-pixel basis.
Metadata File (_MTL.txt): The Metadata File contains basic descriptive information on the Landsat source imagery and details of the ground processing applied to create the Level-1 product. The product metadata includes the level of processing, individual parameters used during processing of the data, and other details such as processing date and system software version.
Ground Control Points File (GCP.txt): The Ground Control Points File contains the ground control points (GCP) used during image processing. GCPs are defined as points on the surface of the earth of known location used to geo-reference Landsat Level-1 imagery.
Gap Mask File (GM_B1.TIF.gz): All Landsat 7 SLC-off scenes (acquired May 2003 to present) include one Gap Mask file for each band to help identify the location of all pixels affected by the original data gaps caused by the Scan Line Corrector (SLC) failure in May 2003.
Verify Image File (VER.jpg) and Verify Report File (VER.txt): Landsat 4-5 TM and Landsat 1-5 MSS scenes include a Verify Image File that displays a grid of verification points in various colors that represent the accuracy of geometric correction. Cross-correlation techniques based on the GLS 2000 dataset are used as reference. When used together with the Geometric Verify Report file, an independent estimate of the accuracy of the scenes can be determined.
README File (README.GTF): The README file contains a summary and brief description of the Level-1 product contents and naming conventions for the files included in the downloaded Level-1 data product.
Technical details relating to format descriptions, file names, and other information are available on the Landsat Project Documentation web page.