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HDF-EOS Development Current Status

Learn about HDF-EOS 2 and 5, formats for EOS standard products. Explore functionalities, conversion tools, and global attributes. Access applications and issue discussion.

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HDF-EOS Development Current Status

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  1. HDF-EOS Development Current Status Larry Klein, Shen Zhao and Ray Milburn L-3 Communications EER Systems, Inc. December 5, 2002 Larry.Klein@L-3com.com, szhao@eos.east.hitc.com

  2. HDF-EOS 2 • HDF4 based, storage format for EOS standard products. • Used operationally by MODIS, MISR, ASTER, Landsat, AIRS and other EOS instruments • Support for Grid/Point/Swath structures • HDF4 and HDF-EOS 2 will be supported by NCSA and NASA for the fore-seeable future.

  3. Current Archive Holdings • GSFC DAAC: AIRS, MODIS L1, L2 Atmos./Ocean • 900 TB • EDC DAAC: Landsat/ASTER/MODIS Land • 500 TB • Langely DAAC: MISR • 300 TB • NSIDC DAAC: MODIS L2, L3 • 20 TB

  4. HDF-EOS 5 • Based on HDF5, a complete rewrite of HDF4 with a different interface. • First released in 2000. • Designed to ‘resemble’ HDF-EOS 2 to the maximum extent possible. • Supports same data structures • Added prefix ‘HE5_’ to HDF-EOS 2 functions. • Doesn’t preclude HDF5 functionality. • Data Type changes, e.g. INT64 -> H5T_NATIVE_LONG

  5. HDF-EOS 2 -> HDF-EOS 5 • HDF-EOS 2 • SWdefdatafield(swathID, fieldname, dimlist, numtype, merge) • HDF-EOS 5 • HE5_SWdefdatafield(swathID, fieldname, dimlist, maxdimlist, numtype, merge, Maxdimlist*) • *New HDF5 functionality passed through. This allows the user to set an upper limit to the size of the dataset.

  6. HDF-EOS 5 • Provide a conversion tool: heconvert • HDF-EOS 2 -> HDF-EOS 5 • compliments HDF4 -> HDF5 conversion tool • HDF-EOS 5 will be used by EOS Aura • Standard format for profile data developed • One GLAS summary product in HDF-EOS 5 • Assume that HDF-EOS 2 producers will convert when PI’s determine that the time is right.

  7. Top Level of HDF-EOS 5 File Root -- “/” HDFEOS INFORMATION HDFEOS STRUC. METADATA ADDITIONAL POINT ARRAY SWATH GRID Global (File) Attributes The new ADDITIONAL Group has global (file) attributes The new functionality is added to the EH(utility) interface.

  8. Swath Structure SwathName Global Attribute <SwathName>:<AttrName> Group Attribute <DataFields>:<AttrName> Data Fields Profile Fields Geolocation Fields Profile Field.n Local Attribute <FieldName>:<AttrName> Profile Field.1 Latitude Longitude Data Field.n Data Field.1 Time CoLatitude Each Data Field can have Attributes and/or Dimension Scales Shaded Objects are implemented in a fixed way so the user doesn’t have direct access via the interface Data Set Group Attribute

  9. HDF-EOS 5 Functionality • Basic File I/O • Fill Values • Compression • Chunking/Tiling • Swath Interface • Grid Interface • Point Interface • Profile Interface • Generalized Array Interface (Zonal Avg.) • Global (File), Group & Local Attributes • External Data Files • Subsetting • Unix/Linux/Windows • Threadsafe Version • FORTRAN, C, C++

  10. ECS support of HDF5 • ECS toolkit V 5.2.8 supports HDF4 and HDF5 - based applications • HDF-EOS 2.8 (hdf4.1r5) • HDF-EOS 5.3 (hdf5-1.4.3) • HDF5 and HDF4 must both be compiled • HDF4 users not affected • HDF5 users must use PGS_MET_SDstart() and PGS_MET_SDend()

  11. ECS support of HDF5 • Both flavors of HDF-EOS (HDF) are part of the ECS baseline. • OS’s: Sun, SGI, IBM, HP, DEC, Windows NT/98, Linux • Compilers: FORTRAN 77/90, C, C++. • ECS will not crack HDF5 - based files for near future. (contents transparent to archive) • Size limit is 2 GBytes

  12. Applications • HE5View (HDF-EOS 5 browser) • Java EOS Browser (HDF-EOS 2 and 5 access) • HDF-EOS processor: convert to GeoTIFF, subset, mosaic, subsample. In Data Pool interface (HDF4 based only) • heconvert (convert HDF-EOS 2 Grid/Point/Swath to HDF-EOS 5 equivalents) • Access libraries and applications at: http://newsroom.gsfc.nasa.gov/sdptoolkit/toolkit.html

  13. Issues • Only gzip (deflate) compression method implemented. • Metadata not updated for swath stitching in unlimited dimension. • File size limit in ECS - Is two Gbytes enough? • Currently in maintenance mode, but user requests are always welcome.

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