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*Processing ASTER HDF files
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This example presents a case-in-point of the need for pyhdf even when
HDF4 format has been superceded by HDF5.  ASTER (Advanced Spaceborne
Thermal Emission and Reflection Radiometer) is an imaging instrument
flying on the satellite Terra, which was launched in December 1999 as
part of NASA's Earth Observing System (EOS).  ASTER has gathered
invaluable data about the Earth's surface, including temperature,
elevation and reflectance.  However, as it was launched before the
rise of HDF5, all of its data files are stored in HDF4.

This example uses pyhdf to process the data files, and several domain-specific
functions to make the ASTER data easily accessible.  Parts of the Aster files
are stored in ODL (Object Description Language), which is processed in the
directory examples/ODL_parsing.

The example itself is ASTER_example.py; the other .py files are helper files
containing domain-specific functions.

Example data files are not provided with pyhdf itself due to size and
redistribution constraints. This example uses an AST05 Surface Emissivity Level
2 data product and an AST08 Surface Kinetic Temperature Level 2 data product.
Consult this table for more information about these data products and how to
order them:

  http://asterweb.jpl.nasa.gov/data_products.asp

Note that this example also depends on PyProj:

  http://code.google.com/p/pyproj/
