U.S. Geological Survey LEVEL-1 PRODUCT README: FAST-L7A FORMAT TABLE OF CONTENTS INTRODUCTION FORMAT ORGANIZATION * DATA FILE NAMES * README * READING DATA GENERAL INFORMATION and DOCUMENTATION ORDER SUPPORT DISCLAIMER INTRODUCTION This product was created by the U.S. Geological Survey (USGS) and contains Landsat 7 data files in FAST-L7A format. The Landsat 7 satellite carries the Enhanced Thematic Mapper Plus (ETM+) sensor and is part of an ongoing mission to provide quality remote sensing data in support of research and applications activities. For information on ETM+ products (Landsat 7): http://edc.usgs.gov/products/satellite/landsat7.html For information on the Landsat Project, missions, and data acquisitions: http://landsat7.usgs.gov For detailed information on the Landsat 7 satellite, the ETM+ sensor, and Landsat 7 data products, see the Landsat 7 Science Data Users Handbook: http://ltpwww.gsfc.nasa.gov/IAS/handbook/handbook_toc.html FORMAT Landsat 7 data are provided in FAST-L7A format for radiometrically and geometrically corrected (level-1G) products and for level-1G SLC-off gap-filled products. The level-1G image data are provided in 8-bit (unsigned integer) digital numbers (DN). The FAST-L7A file format is described in detail in the "Level 1 Product Output File, Data Format Control Book, L7-DFCB-04, Vol. 5, Book 2, Revision 6, April 2004": http://landsat7.usgs.gov/documents/L7-DFCB-04-L1p-DFCB.pdf ORGANIZATION Landsat 7 data files are stored separately from the FAST-L7A directory file, which contains the file names and pointers for the data files. The data is provided in band sequential (BSQ) format (i.e., each band is stored in a separate image file, and scan lines are sequentially written to the same image file). Landsat 7 ETM+ SLC-off gap-filled products will include an additional directory (GAP_MASK) that contains a set of flat binary scan gap mask files (one per band). The FAST-L7A product consists of header files and linked image files: Header File Administrative Record: Contains information that identifies the product, the image, and the data specifically needed to ingest the imagery for each particular band. In order to import the image data, it is necessary to read the entries in the administrative record. Radiometric Record: Contains the coefficients needed to convert the image values into at-satellite spectral radiance for each particular band. Geometric Record: Contains geodetic location information. To align the imagery to other data sources, it is necessary to read the entries in the geometric record for each particular band. A separate header file exists for each of the following band groups: 1. Panchromatic 2. Visible Near Infrared/Shortwave Infrared (VNIR/SWIR) 3. Thermal Image File Each image file contains one ETM+ band of image pixels. There are no header records, prefix data, or suffix data in the image records. Image data are unblocked, and image files are 8-bit unsigned integers. * DATA FILE NAMES The file naming convention for FAST-L7A is as follows: L7fppprrr_rrrYYYYMMDD_AAA.FST where: L7 = Landsat-7 mission f = ETM+ data format (1 or 2) (data not pertaining to a specific format defaults to 1) ppp = starting path of the product rrr_rrr = starting and ending rows of the product YYYYMMDD = acquisition date of the image AAA = file type: B10 = band 1 B20 = band 2 B30 = band 3 B40 = band 4 B50 = band 5 B61 = band 6L (low gain) B62 = band 6H (high gain) B70 = band 7 B80 = band 8 HPN = panchromatic band header file HRF = VNIR/SWIR bands header file HTM = thermal bands header file MTL = Level-1 metadata FST = FAST-L7A file extension * GAP MASKS Level-1G SLC-off gap-filled products include a scan gap mask for each band, located in a separate directory. Gap mask files are provided in compressed (GZIP) GeoTIFF format. The file name convention for gap mask files is identical to that described above for FAST-L7A format, with the exception of the file extension (.TIF.GZ). * README The README.FF7 (this document) is an ASCII text file. * READING DATA Delivered on tape: Data on 8-mm, high-density (Exabyte) tape and on digital linear tape (DLT) are tarred per Institute of Electrical and Electronics Engineers (IEEE) POSIX standard 1003.1, preserving file names. To read a tar tape on a computer with a UNIX operating system, type: tar -xvf / Command key arguments include: x = data are to be read from tape v = requests verbose output (that is, processed file names will be listed) f = archive name is specified The is system specific and may specify a device such as a tape drive or a file path. Specific parameters depend upon local server or workstation configurations. An example of extracting a specific directory from a tar-formatted tape: tar -xvf / 1 Other operating systems may require additional software for reading tar-formatted media. Delivered on compact disc (CD): Data files are not packed and conform to ISO 9660 Level-2 standards. Delivered via file transfer protocol (FTP): Data files are not packed or compressed. No software is included on this product for viewing Landsat data. GENERAL INFORMATION and DOCUMENTATION Landsat 7 (ETM+): http://landsat7.usgs.gov/ http://edc.usgs.gov/products/satellite/landsat7.html Landsat 4-5 (TM): http://edc.usgs.gov/products/satellite/tm.html Landsat 1-5 (MSS): http://edc.usgs.gov/products/satellite/mss.html FGDC metadata: http://www.fgdc.gov/clearinghouse/clearinghouse.html Data restrictions and citation: http://edc.usgs.gov/about/customer/citation.html PRODUCT SUPPORT For further information on this product, contact USGS EROS Data Center Customer Services: Customer Services U.S. Geological Survey EROS Data Center 47914 252nd Street Sioux Falls, SD 57198-0001 Tel: 800-252-4547 Tel: 605-594-6151 TDD: 605-594-6933 Fax: 605-594-6589 Email: custserv@usgs.gov web: http://edc.usgs.gov/about/customer/index.html For information on other products from USGS EROS Data Center: http://edc.usgs.gov/ For information on other USGS products: http://ask.usgs.gov/ or call 1-888-ASK-USGS (275-8747) DISCLAIMER Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Publication Date: March 5, 2004