USGS NATIONAL LAND ARCHIVE PRODUCTION SYSTEM PRODUCT README: HDF FORMAT TABLE OF CONTENTS INTRODUCTION FORMAT ORGANIZATION * DATA FILE NAMES * README * READING DATA GENERAL INFORMATION and DOCUMENTATION ORDER SUPPORT DISCLAIMER INTRODUCTION This product was produced by the U.S. Geological Survey (USGS) and contains Landsat 7 data files in standard Hierarchical Data Format (HDF) 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. Information on the Landsat-7 Program, including information about the Landsat-7 satellite, the ETM+ sensor, and Landsat-7 data collection, is available in the "Landsat 7 Science Data Users Handbook." The HDF files are described in detail in the "Level 1 Product Output Files Data Format Control Book, Volume 5, Book 2." The "National Land Archive Production System (NLAPS) Systematic Format Description Document" provides an overview of multiple product formats including HDF. (All documents are obtainable at the Web site: http://edcwww.cr.usgs.gov/customer.html) FORMAT The Landsat-7 data are provided in HDF for radiometrically corrected (level-1R) products and for radiometrically and geometrically corrected (level-1G) products. Data may be represented in both binary and American Standard Code for Information Interchange (ASCII) formats. Bit and byte ordering follow conventions set by the Institute of Electrical and Electronics Engineers (IEEE) with the term "byte" being synonymous with octet as used by the International Organization for Standardization. For more information on HDF structures, visit the following Web sites: HDFinfo at: http://www.scispy.com/ The National Center for Supercomputing Applications HDF Home Page at: http://hdf.ncsa.uiuc.edu/ ORGANIZATION The Landsat-7 data files are stored separately from the HDF directory file, which contains the file names and pointers for the data files. The level-1R and level-1G image files are in absolute radiance units scaled to 16 bits and 8 bits, respectively. * DATA FILE NAMES Except for the calibration parameter file, the file naming convention for HDF is as follows: L7fppprrr_rrrYYYYDD_AAA.XXX where: L7 = the Landsat-7 mission. f = the ETM+ data format. ppp = the starting path of the product. rrr_rrr = the starting and ending rows of the product. YYYYDD = the acquisition date of an image. AAA = the file type: B10 = the 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 = the band 7 CAL = internal calibrator (1R only) B80 = the band 8 GEO = geolocation (1R only) HDF = HDF directory file SD = consensus SCD (1R only) TA = LPS metadata (1R only) TL = LPGS metadata PCD = consensus PCD (1R only) SLO = scan line offset (1R only) XXX = product type (L1R or L1G). Calibration parameters are stored as ASCII text using an object data language syntax developed by the Jet Propulsion Laboratory. The naming convention for the calibration parameter file is derived from the file name assigned by the Image Assessment System and is annotated as follows: L7CPFYYYYDD_YYYYDD_nn where L7 = the Landsat-7 mission. CPF = the calibration parameter file. * README The README.TXT is a text file and is this document. * READING DATA * Delivered On Tape - Data on 8-mm, high-density (Exabyte) tapes are tarred Per Institute of Electrical and Electronics Engineers 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 = indicates that the data are to be read from tape. v = requests verbose output (that is, processed file names will be listed). f = indicates that the archive name is specified. The device name is system specific and may specify a device such as a tape drive or a file path. Specific parameters depend upon local workstation configurations. * Delivered On CDROM: Data files are not packed. ISO 9660 Level 2. * Delivered Via File Transfer Protocol (FTP): Data files are not packed or compressed. * Delivered On Digital Linear Tape (DLT): Data files are not packed or compressed. Surcharge required. GENERAL INFORMATION and DOCUMENTATION For information about the Landsat 7 Data Set, including tutorials, product standards, and software, see: http://landsat7.usgs.gov/ No software is included on this product for viewing Landsat 7 data. ORDER SUPPORT Direct questions about orders to the USGS EROS Data Center's Customer Services at 1(800)252-4547 or contact an Earth Science Information Center (ESIC) office. The USGS EROS Data Center is available at: http://edcwww.cr.usgs.gov/eros-home.html and Customer Services is available at: http://edcwww.cr.usgs.gov/customer.html A list of ESIC offices is available at: http://mapping.usgs.gov/esic/esic_index.html For information about other USGS products, see: http://mapping.usgs.gov/esic/to_order.html or call 1-888-ASK USGS. DISCLAIMER Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.