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ACRES
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Updated:
12 September 2007
ACRES file formats for optical satellite imageryFile FormatsACRES satellites image products are produced in a range of file formats. Format availability is dependent on the type and processing level of the image data. Users should be aware that ACRES products are intended for use with specialised remote sensing software with specific applications (eg spectral analysis) as distinct from GIS and other vector based software. File formats supported by ACRES include: GeoTiff, CCRS, CEOS, EOSAT, Fast7A and HDF. For more information regarding file formats please see the ACRES technical documents. The digital product formats used by ACRES have been developed by a range of organisations. These organisations include satellite operators, e.g. NASA, and space industry organisations including:
Generic image formatsLandsat MSS & TMCCRS formatThe CCRS formats are part of the LGSOWG family. For products in CCRS format, customers may request a supplemental file which can be written to tape either before or after the imagery file. The supply of this supplemental file is optional and is usually only supplied at customer request. The supplemental file contains ephemeris and attitude data, mission telemetry, ground control points (GCP's - only if used) etc. Since 1996 the supplemental file has been supplied automatically with Level 9 and 10 products.
EOSAT Fast FormatACRES can generate this format for both Landsat TM and MSS data. Fast format is a simpler format than the LGSOWG/CEOS formats, with an ASCII header file and separate files for each image band (band sequential structure - BSQ). The version of Fast Format produced by ACRES is as specified in the EOSAT Fast Format Document, version B, effective 1 October, 1991. This version does not include the trailer file which contains the ephemeris data as specified in a later version (also called version B) of the document, effective 1 November, 1993. Fast Format can be read by practically all image analysis systems. GeoTIFFLandsat ETM+ACRES is able to supply Landsat 7 ETM+ digital products in Fast-L7A and HDF formats. (a) Fast-L7A Format This format is defined by the NASA document: Earth Science Data and Information System (ESDIS)
The Fast-L7A format is based on the Space Imaging EOSAT Fast Version C format. Modifications have been made to the Fast Version C format to accommodate features of the ETM+ instrument and data. ACRES are able to provide the following Level 1 Fast-L7A products:
(b) HDF Format The Hierarchical Data Format "HDF" for Landsat ETM+ is defined by two documents. These two documents are the ESDIS document for the Fast-L7A format specified above, and a complementary document:Landsat 7 System Zero-R Distribution Product
This document is applicable to the Landsat 7 ETM+ Level 0 (essentially raw) data available from the USGS EROS data Center. The document describes all the necessary data to perform radiometric and geometric correction to Level 0 data. GeoTIFFALOS PRISM, AVNIR-2 and PALSARCEOS (Committee on Earth Observation Satellites)The CEOS format image files are a combination of ASCII and Binary data. Metadata is contained with CEOS format data which can be accessed through reference to the CEOS format in combination with an appropriate data viewer. PRISM, AVNIR-2 and PALSAR CEOS format files contain the same structure but the metadata content and field sizes differ between the sensor.
NOAA AVHRR and MODISHDFThe Hierarchical Data format (HDF) for MODIS and AVHRR is a library and multi-object file format for the transfer of graphical and numerical data between machines. HDF is commonly used in scientific applications because of its portability between different systems and due to the self-describing nature of the format. GeoTIFFGeneric image formatsGeographic Tagged Image File Format (GeoTIFF)ACRES Landsat, MODIS and ALOS imagery is now available in Geographic Tagged Image File Format (GeoTIFF). Introduced in response to requests from ACRES customers, this alternative image format is available for:
GeoTIFF is becoming a popular industry-wide image format for data storage and transfer across operating system environments and applications. GeoTIFF offers the capability to embed a wide range of georeferencing information (e.g. projection, datums and ellipsoids, coordinate values) as compliant descriptive tags (metadata) and structures within the TIFF (Tagged Image File Format) file.
Supported file formats for ACRES products
ACRES encourages, and where possible assists, the major software vendors in the support of ACRES supplied product formats. The following table provides a summary of the digital image product formats supported by ACRES. If more than one format is available for a particular sensor/processing level combination, ACRES recommended format is shown in bold.
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