LSDS-1823 Version 2.0
Department of the Interior U.S. Geological Survey
Landsat 1-9 Full Resolution Browse (FRB) Data Format Control Book (DFCB)
Version 2.0
September 2020
Landsat 1-9 Full Resolution Browse (FRB) Data Format Control Book (DFCB)
September 2020
Approved By:
______Chris Engebretson Date Landsat DPAS CCB Chair U.S. Geological Survey
EROS Sioux Falls, South Dakota
- ii - LSDS-1823 Version 2.0 Executive Summary
This Data Format Control Book (DFCB) presents detailed data format, the general algorithm for generating browse images, and the compression methods used. These Full Resolution Browse (FRB) images are based on Level 1 output products. Images are produced in the Cloud Optimized Geographic Tagged Image File Format (GeoTIFF) (COG) or as a Joint Photographic Experts Group (JPEG) file format.
This document is under Landsat Data Processing and Archive System (DPAS) Configuration Control Board (CCB) control. Please submit changes to this document, as well as supportive material justifying the proposed changes, via a Change Request (CR) to the Process and Change Management Tool.
- iii - LSDS-1823 Version 2.0 Document History
Document Document Publication Change Number Version Date Number LSDS-1823 Version 1.0 November 2017 CR 13763 LSDS-1823 Version 2.0 September 2020 CR 15316
- iv - LSDS-1823 Version 2.0 Contents
Executive Summary ...... iii Document History ...... iv Contents ...... v List of Tables ...... v Section 1 Introduction ...... 1 1.1 Background ...... 1 1.2 Mission Objectives ...... 1 1.3 Purpose...... 1 1.4 Scope ...... 2 1.5 Document Organization ...... 2 1.6 References ...... 2 1.6.1 Reference Documents ...... 2 Section 2 Data Format Definition ...... 4 Section 3 File Naming Convention ...... 6 Section 4 Browse Generation ...... 8 4.1 Assumptions ...... 8 4.2 Method ...... 8 4.2.1 Reflective Band Browse ...... 8 4.2.2 Thermal Browse ...... 9 4.2.3 Quality Band Browse ...... 9 Appendix A Acronyms ...... 10
List of Tables
Table 1-1. Reference Documents ...... 3 Table 2-1. Browse Products Available...... 4 Table 2-2. Quality Band Bit Fields ...... 5 Table 3-1. File Naming Convention ...... 6 Table 4-1. Full Resolution Browse Reflective Band Combinations ...... 9 Table 4-2. Full Resolution Browse Thermal Band ...... 9
- v - LSDS-1823 Version 2.0 Section 1 Introduction
The Landsat mission is a joint mission formulated, implemented, and operated by the National Aeronautics and Space Administration (NASA) and the Department of Interior (DOI) U.S. Geological Survey (USGS). Landsat is a remote sensing satellite mission providing coverage of the Earth’s land surfaces. This mission continues the 40+ years of global data collection and distribution provided by the Landsat series of satellites.
1.1 Background The goal of Landsat is to continue the collection, archival, and distribution of multispectral imagery affording global, synoptic, and repetitive coverage of the Earth’s land surfaces at a scale where natural and human-induced changes can be detected, differentiated, characterized, and monitored over time. The Landsat programmatic goals are stated in the United States Code, Title 15 Chapter 82 “Land Remote Sensing Policy” (derived from the Land Remote Sensing Policy Act of 1992). This policy requires that the Landsat Program provide data into the future that are sufficiently consistent with previous Landsat data to allow the detection and quantitative characterization of changes in or on the land surface of the Earth. The highly successful Landsat series of missions have provided satellite coverage of the Earth’s continental surfaces since 1972. The data from these missions constitute the longest continuous record of the Earth’s surface as seen from the space.
1.2 Mission Objectives The major mission objectives are as follows:
• Collect and archive medium resolution (circa 30 meter (m) spatial resolution) multispectral image data affording seasonal coverage of the global land mass for a period of no less than five years, with no credible single-point failures. • Collect and archive medium-low resolution (circa 120 m ground-sample distance) thermal image data affording seasonal coverage of the global land mass for a continuous period of no less than five years, with no credible single-point failures. • Ensure that data from Landsat missions are sufficiently consistent, in terms of acquisition geometry, calibration, coverage characteristics, spectral characteristics, output product quality, and data availability to permit studies of land cover and land use change over multi-decadal periods. • Distribute Landsat data products to the public on a nondiscriminatory basis.
1.3 Purpose This Data Format Control Book (DFCB) describes the detailed format of the full resolution Landsat browse imagery. The definition of a browse image has changed greatly since the Earth Resources Observation and Science (EROS) Center first started to produce imagery. Early browse images were solely defined by two criteria: 1) their small file size and 2) their ability to permit the user to visually recognize the area covered and to assess overall image cloud cover. With the growth of Google™ Earth and other web mapping applications, the original intent of browse has evolved from use
- 1 - LSDS-1823 Version 2.0 as a tool for image selection to a visual entity that can also serve for mapping and interpretation.
Landsat browse images are created for quick and efficient image selection and for visual interpretation. The following criteria are critical to meet user needs for Landsat browse images:
• Provide full spatial resolution browse for local area evaluation • Provide browse that is geo-registered and Geographical Information Systems (GIS)-ready
1.4 Scope This document describes the detailed data format, the general algorithm for generating browse images, and the compression methods.
1.5 Document Organization This document contains the following sections:
• Section 1 contains an introduction • Section 2 defines the data format • Section 3 describes the naming convention for the files • Section 4 describes the generation of browse images from the Landsat Level 1 product • Appendix A provides a list of acronyms
1.6 References
1.6.1 Reference Documents The documents in Table 1-1 provide additional background and context to this document.
Document Version / Release Document Title Number Date LSDS-1388 Version 2.0 / Landsat Cloud Optimized GeoTIFF (COG) Data Format January 2020 Control Book (DFCB) LSDS-1414 Version 3.0 / Landsat 7 (L7) Enhanced Thematic Mapper Plus (ETM+) September 2020 Collection 2 (C2) Level 1 (L1) Data Format Control Book (DFCB) LSDS-1415 Version 3.0 / Landsat Thematic Mapper (TM) Collection 2 (C2) Level 1 September 2020 (L1) Data Format Control Book (DFCB) LSDS-1416 Version 3.0 / Landsat Multispectral Scanner (MSS) Collection 2 (C2) September 2020 Level 1 (L1) Data Format Control Book (DFCB) LSDS-1822 Version 6.0 / Operational Land Imager (OLI) - Thermal Infrared Sensor September 2020 (TIRS) Collection 2 (C2) Level 1 (L1) Data Format Control Book (DFCB) GeoTIFF Format Specification, GeoTIFF Revision 1.0, Specification Version 1.8.2. 28 December 2000.
- 2 - LSDS-1823 Version 2.0 Document Version / Release Document Title Number Date JPEG File Interchange Format, Version 1.02.
Table 1-1. Reference Documents
- 3 - LSDS-1823 Version 2.0 Section 2 Data Format Definition
Landsat Full Resolution Browse (FRB) files are stored in Cloud Optimized Geographic Tagged Image File Format (GeoTIFF) (COG) and are either Joint Photographic Experts Group (JPEG) compressed or DEFLATE compressed depending on the type of browse file. FRB files are generated as “Pixel is Point,” meaning they are aligned to the center of each pixel. Up to three browse files may be associated with each scene (see Table 2-1).
• Reflective FRB: Three bands, 8-bits per band • Thermal FRB: One band, 8-bit grayscale • Quality Band (QB) FRB: An 8-bit version of the Level 1 product Quality Assessment (QA) band and Level 1 product RADSAT QA band with a color map depicting the most important bit (see Table 2-2) • Five layers of overviews are added to the GeoTIFF images at 1/2, 1/4, 1/8, 1/16, and 1/32 of the original image resolution • The overviews are tiled and resampled using the average of all non-fill pixels, photometrically interpreted using YCBCR scheme, and JPEG compressed with a quality of 75 • For the 8-bit QB, the overviews are compressed using DEFLATE compression, as it is lossless
Component OLI / TIRS ETM+ TM MSS 3-band Reflective browse X X X X Thermal browse X X X Quality band browse X X X X
Table 2-1. Browse Products Available
A JPEG version of each browse is also available for quick looks, also providing smaller file sizes.
- 4 - LSDS-1823 Version 2.0 16-Bit Radiometric 16-Bit Quality (QA) 8-Bit QB 8-Bit QB 8-Bit QB Color Priority Saturation Band OLI / TIRS ETM+ / TM MSS (RADSAT QA) Band
Bit Description Bit Description Bit Description Description Description
Designated Designated Designated Designated Highest 0 0 Fill Fill Fill Fill | | Dilated 1 | Cloud |
Dropped Dropped Dropped |
9 Pixel Pixel Pixel | 1
Terrain | 11 Occluded occlusion |
| Band 1-7, 9 Radiometric Radiometric Radiometric 0-6, 8* 2 | Saturation Saturation Saturation Saturation | | 3 Cloud 3 Cloud Cloud Cloud |
Cloud Cloud Cloud | 4 4 Unused Shadow Shadow Shadow |
| 5 Snow 5 Snow/Ice Snow/Ice Unused v
2 Cirrus 6 Cirrus Unused Unused Lowest
6 Clear 7 Unused Unused Unused Unused
7 Water
Cloud 8-9 Confidence Cloud 10-11 Shadow Confidence
Snow/Ice 12-13 Confidence
7, 10, Cirrus Unused 14-15 12-15 Confidence * For ETM, bit 8 in RADSAT QA indicates Band 6H data saturation. It indicates Band 8 data saturation in OLI / TIRS, and it is unused in
TM and MSS. Saturation in any bands sets 8-bit QA band.
Table 2-2. Quality Band Bit Fields
- 5 - LSDS-1823 Version 2.0 Section 3 File Naming Convention
The file names are based on the Landsat Product Identifier, which has the following format:
LXSS_LLLL_PPPRRR_YYYYMMDD_yyyymmdd_CC_TX_FFF.
Table 3-1 contains the details and explanation of the file name.
L Landsat Sensor O = OLI only T = TIRS (Landsat 8-9) only X or TM (Landsat 4-5) C = OLI and TIRS E = ETM+ M = MSS Satellite 09 = Landsat 9 08 = Landsat 8 07 = Landsat 7 SS 05 = Landsat 5 04 = Landsat 4 03 = Landsat 3 02 = Landsat 2 01 = Landsat 1 Processing Level “L1TP”: Precision Terrain LLLL “L1GT”: Systematic Terrain “L1GS”: Systematic PPP Three-digit Worldwide Reference System (WRS) path RRR Three-digit WRS row YYYYMMDD Acquisition Year (YYYY) / Month (MM) / Day (DD) yyyymmdd Processing Year (yyyy) / Month (mm) / Day (dd) CC Collection Number Collection Category: RT = Real-Time TX T1 = Tier 1 (stackable) T2 = Tier 2 (non-stackable) File Type _TIR = Thermal Greyscale _FFF _QB = Quality Band
JPEG = .jpg (Individual download)
Table 3-1. File Naming Convention
The Reflective, Thermal, and Quality band Browse are produced in a COG format as described in Section 2. These files are typically about 2-14 MB in sizes, depending on the content of the image. Full Resolution Browse are also available in the JPEG File
- 6 - LSDS-1823 Version 2.0 Interchange Format (JFIF version 1.01). These files are typically about 2-6 MB in size, although the size varies significantly across scenes and browse types.
- 7 - LSDS-1823 Version 2.0 Section 4 Browse Generation
4.1 Assumptions The Landsat Product Generation System (LPGS) generates browse images from the Level 1 product band files. The following assumptions are made about the Level 1 product:
• Landsat 8-9 OLI: The Operational Land Imager (OLI) reflective bands are 30- meter resolution and stored as 16-bit unsigned integers that can be linearly scaled to the Top of Atmosphere (TOA) reflectance. • Landsat 8-9 TIRS: The Thermal Infrared Scanner (TIRS) bands are resampled to 30-meter resolution and stored as 16-bit unsigned integers that can be linearly scaled to the TOA brightness temperature. • Landsat 7 ETM+, Landsat 4-5 TM: The Enhanced Thematic Mapper plus (ETM+) and Thematic Mapper (TM) reflective bands are 30-meter resolution and stored as 8-bit unsigned integers that can be linearly scaled to the TOA reflectance. • Landsat 7 ETM+, Landsat 4-5 TM: The ETM+ and TM thermal bands are 30- meter resolution and stored as 8-bit unsigned integers that can be linearly scaled to the TOA brightness temperature. • Landsat 1-5 MSS: The Multispectral Scanner (MSS) reflective bands are 60- meter resolution and stored as 8-bit unsigned integers that can be linearly scaled to the TOA reflectance. • The LPGS generates a 16-bit QA band (pixel level metadata) and Radiometric Saturation QA band (QA_RADSAT) as part of the Level 1 product.
4.2 Method
4.2.1 Reflective Band Browse The reflective browse (or FRB Reflective image) is generated by reading three bands from the Level 1 product (see Table 4-1), converting to reflectance (using the parameters from the Level 1 product metadata file). The browse data retains full spatial resolution (30 or 60 meters) and retains the map projection of the source data (normally Polar Stereographic (PS) for Antarctic scenes and Universal Transverse Mercator (UTM) elsewhere). Radiometrically, each band is scaled to 8-bits per pixel with a gamma stretch:
(1/gamma) DNB = 255 * Ρp where Ρp is the TOA reflectance and gamma = 2.0. The three bands are then combined to generate a 24-bit color image, which is stored as a JPEG compressed COG with a quality of 75 percent.
- 8 - LSDS-1823 Version 2.0 Sensor Red Green Blue Combination OLI 6, 5, 4 ETM 5, 4, 3 TM 5, 4, 3 L1-3 MSS 5, 7, 4 L4 MSS 2, 4, 1 L5 MSS (Pre August 19, 1995) 2, 4, 1 L5 MSS (Post August 19, 1995) 2, 3, 1
Table 4-1. Full Resolution Browse Reflective Band Combinations
4.2.2 Thermal Browse The thermal browse (or FRB Thermal image) is generated by reading the thermal band from the Level 1 product (see Table 4-2), converting to brightness temperature (using the parameters from the Level 1 product metadata file), clipping to a range of -40 to 50 degrees Celsius, then scaling to an 8-bit grayscale image. MSS does not have a thermal band. The browse data retains full spatial resolution (30 meters) and retains the map projection of the source data (normally PS for Antarctic scenes and UTM elsewhere). The resulting image is stored as a JPEG compressed COG with a quality of 75 percent. This COG image is available for download, which is typically about 2-14 MB in size. A JPEG image is also available, typically about 3-6 MB in size, although the exact size varies depending on the compression. When a COG image is converted to JPEG, a greater compression factor is applied to OLI/TIRS images in order to keep all the JPEG file sizes under 6 MB.
Sensor Band TIRS 10 ETM 6 TM 6 MSS Not Available
Table 4-2. Full Resolution Browse Thermal Band
4.2.3 Quality Band Browse The 8-bit Quality Band (QB) is generated from the Landsat Level 1 16-bit QA band and Level 1 16-bit Radiometric Saturation QA band by reading a subset of the bit fields. Table 2-2 displays the exact layout of the bit fields. The 8-bit QB is distributed as a color mapped COG.
- 9 - LSDS-1823 Version 2.0 Appendix A Acronyms
C2 Collection 2 CCB Configuration Control Board COG Cloud Optimized GeoTIFF CR Change Request DFCB Data Format Control Book DOI Department of the Interior DPAS Data Processing and Archive System EROS Earth Resources Observation and Science ETM+ Enhanced Thematic Mapper Plus FRB Full Resolution Browse GeoTIFF Geographic Tagged Image File Format GIS Geographical Information System JFIF JPEG File Interchange Format JPEG Joint Photographic Experts Group L1 Level 1 or Landsat 1 L1GS Level 1 Geometric Systematic L1GT Level 1 Systematic Terrain (Corrected) L1TP Level 1 Terrain Precision (Corrected) L2 Landsat 2 L3 Landsat 3 L4 Landsat 4 L5 Landsat 5 L7 Landsat 7 L8 Landsat 8 L9 Landsat 9 LPGS Landsat Product Generation System LSDS Land Satellites Data System m Meter MB Megabyte MSS Multispectral Scanner NASA National Aeronautics and Space Administration OLI Operational Land Imager PS Polar Stereographic QA Quality Assessment QB Quality Band RT Real Time T1 Tier 1 T2 Tier 2 TIRS Thermal Infrared Sensor TM Thematic Mapper TOA Top of Atmosphere
- 10 - LSDS-1823 Version 2.0 USGS U.S. Geological Survey UTM Universal Transverse Mercator WRS Worldwide Reference System
- 11 - LSDS-1823 Version 2.0