U. S. Geological Survey ASTER PRODUCT README: HDF-EOS TABLE OF CONTENTS INTRODUCTION FORMAT ORGANIZATION * DATA FILE NAMES * README * FILE SUMMARY * READING DATA GENERAL INFORMATION and DOCUMENTATION ORDER SUPPORT DISCLAIMER INTRODUCTION ASTER level 1 data are processed by the Japanese Ground Data System (GDS) and archived by the Land Processes Distributed Active Archive Center (LP DAAC), at the USGS EROS Data Center (EDC). The data contains Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data files in the Hierarchical Data Format for Earth Observing System (HDF-EOS). ASTER is one of the five state-of-the-art instrument systems on-board Terra, a satellite launched in December 1999 as part of NASA's Earth Observing System. The data have a unique combination of wide spectral coverage and high spatial resolution in the visible near-infrared, shortwave infrared, and the thermal infrared regions. It is a cooperative effort between NASA and Japan's Ministry of Economy, Trade and Industry (METI) and the Earth Remote Sensing Data Analysis Center (ERSDAC). ASTER data contributes to a wide array of global change-related application areas including vegetation and ecosystem dynamics, hazard monitoring, geology and soils, land surface climatology, hydrology, and land cover change. Additional information may be found on the following web pages: ASTER homepage: http://asterweb.jpl.nasa.gov/ LP DAAC ASTER Data Products, overview, and examples: http://edcdaac.usgs.gov/aster/asterdataprod.html Japanese ASTER home: http://www.gds.aster.ersdac.or.jp/ FORMAT ASTER data products are delivered in HDF-EOS format with the bands written in band sequential (BSQ) format. HDF-EOS was designed to accommodate most of the data generated by the EOS satellites. HDF was originally developed by the National Center for Supercomputing Applications, University of Illinois, at Urbana-Champaign (URL: www.ncsa.uiuc.edu/About/NCSA/) to handle the transportation and storage of scientific data, in particular the output from supercomputer simulation results. Using the original HDF, the NASA's Earth Observing System Data and Information System (EOSDIS) project has implemented specific data models to handle swaths, grids, and points. This specific implementation is referred to as HDF-EOS. The HDF-EOS files are described in detail in the "HDF-EOS Tools and Information Center" which may be found at: http://hdfeos.gsfc.nasa.gov/hdfeos/index.cfm ORGANIZATION The following are for the ASTER data products available from the LP DAAC: Level 1 Data Products: The ASTER instrument produces two types of Level 1 data AST_L1A Raw (similar to Landsat 7, Level 0) These are uncorrected data, although correction coefficients are included with the granule. AST_L1B Systematic correction (similar to Landsat 7, Level 1G) Includes radiometric and geometric correction and those data are processed to unsigned 8-bit digital numbers. Level 2 Standard Data Products: created from existing Level 1 data. AST_06 This is a "standard" decorrelation stretch that is applied consistently to all bands and granules. It uses standardized parameters and is different from the "granule-specific" range that is customer-specified in the case of the on-demand decorrelation stretch product described below. AST_06 could be either STANDARD or ON-DEMAND product. AST_06V VNIR 15m resolution AST_06S SWIR 30m resolution AST_06T TIR 90m resolution Level 2 On-Demand Data Products: created on-demand from existing Level 1 data. Only the DEM products are archived. AST_06 Decorrelation stretch This is a granule-specific decorrelation stretch product. The customer selects the band combination and desired enhancement for that particular granule. AST_06VD VNIR 15m resolution AST_06SD SWIR 30m resolution AST_06TD TIR 90m resolution AST_04 Brightness temperature Radiance at the sensor is converted to an apparent temperature. No atmospheric correction is included. TIR 90m resolution AST_05 Surface emissivity Surface emissivity includes recovering accurate and precise emissivities for mineral substrates, and estimating accurate and precise surface temperatures especially over vegetation, water and snow. TIR 90m resolution AST_07 Surface reflectance Corrects for sun-satellite geometry and atmospheric conditions. VNIR 15m resolution SWIR 30m resolution AST_08 Surface kinetic temperature Based on the surface emissivity (AST_05) product and includes atmospheric surface radiance correction. TIR 90m resolution AST_09 Surface radiance Corrected for sun-satellite geometry and atmospheric conditions. VNIR 15m resolution SWIR 30m resolution AST_09T Surface radiance (TIR) Corrected for sun-satellite geometry and atmospheric conditions. TIR 90m resolution AST13POL Polar Surface and Cloud Classification A classification map that discriminates between different surface and cloud features over polar areas. VNIR sub-sampled by half from 15m to 30m resolution SWIR 30m resolution TIR resampled from 90m to 30m resolution AST14DEM DEM product, utilizing ASTER L1A data as input. The DEM is produced by combining bands 3n & 3b (n=nadir looking, b=backward-looking). This product is archived by the LP DAAC. 30m resolution * DATA FILE NAMES The following defines the file names associated with ASTER product: EOS Data Gateway (EDG) Granule ID: SC:AST_L1A.002:2004799662 AST_L1A: Processing level (ASTER Level 1A) 002: Version of the software and algorithm that produced granule. 2004799662: Unique number identifying granule HDF File Name: pg-PR1A0000-2001111802_042_013 Metadata File: pg-PR1A0000-2001111802_042_013.met (ECS metadata) PR1A0000: Processing level (ASTER Level 1A) 2001: Production date (year) 11: Production date (month) 18: Production date (day) 02: Sequence number of production plan for that particular day 042: Processing strip number 013: Sequence number in the processing strip Embedded GDS ID: ASTL1A 0111051037240111180891 (located in HDF file) GDS ID format: 'ASTL1A YYMMDDHHMMSSyymmddNNNN' YYMMDD: observation date HHMMSS: observation time yymmdd: the data granule generation date NNNN: the data granule sequential number per day To match the file to the granule ID, determine the acquisition date from the embedded metadata and use this as a search parameter in the EOS Data Gateway (EDG). For details of structure of embedded metadata, please reference the page: ftp://asterweb.jpl.nasa.gov/outgoing/handbook/aster_user_guide_v2.pdf (page 55, Table 7, and page 71-76). * README The 0readme.txt is a text file and is this document. * FILE SUMMARY The 0files.sum file contains information for the files on the media (except for data through File Transfer Protocol (FTP)). It includes the order number, granule ID with associated media file names, acquisition date of the granule and granule center latitude/longitude coordinates. * READING DATA Media available for Level 1A, 1B, and Decorrelation Stretch data: FTP CD DVD DLT Media available for On-Demand data: FTP Delivered on compact disc (CD) and digital versatile disc (DVD): 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 and staged for 72 hours. Delivered on digital linear tape (DLT): Data files are not packed or compressed. GENERAL INFORMATION and DOCUMENTATION For information about the ASTER data set, including product standards, data processing, and software, please reference the following: Product Information http://edcdaac.usgs.gov/aster/asteroverview.html http://asterweb.jpl.nasa.gov/documents/documents.htm http://asterweb.jpl.nasa.gov/documents/ASTER_L1_Product_Spec_Ver_1.3_July01.pdf http://asterweb.jpl.nasa.gov/documents/ASTERHigherLevelUserGuideVer2May01.pdf ASTER Standard Data Products Catalog http://edcdaac.usgs.gov/aster/asterdataprod.html http://edcdaac.usgs.gov/aster/asterprocessing.html Algorithm Theoretical Basis Document (ATBD) http://eospso.gsfc.nasa.gov/atbd/astertables.html EOS Data Products Handbook http://eospso.gsfc.nasa.gov/eos_homepage/misc_html/data_prod.html No software is included with this product for viewing ASTER data. ORDER SUPPORT Direct questions about orders to the Land Processes Distributed Active Archive Center (LP DAAC) Customer Service at: Phone: 605-594-6116 Toll Free: 1-866-573-3222 Fax: 605-594-6963 USGS LP DAAC: http://edcdaac.usgs.gov/ Customer Services: http://edcdaac2.usgs.gov/custhelp/index.html For information about other USGS products, see: 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: January 15, 2003