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The HDF4 OPeNDAP handler (hdf4_handler) is a software package that can be used to access HDF4 data via OPeNDAP's Data Access Protocol.
The original version of the handler was implemented in 1998 by NASA JPL.
The HDF Group enhanced the HDF4 OPeNDAP handler to support the access of NASA HDF-EOS2 and some HDF4 products
via OPeNDAP's visualization client tools since 2010.
The handler is included in the Hyrax release at
OPeNDAP website
.
Since the Hyrax 1.13.2 release, the HDF4 OPeNDAP handler has become a module of the Hyrax Back End Server(BES). The HDF Group still maintains and develops this module. The latest information about the HDF4 OPeNDAP handler can be found at Hyrax's github repository here.
The image below, generated by Panoply
via OPeNDAP,
shows the NASA GES DISC AIRS ozone data near the South Pole in January 2013.
This is possible through the enhanced module of the hdf4_handler (Download).
Since the Hyrax 1.13.2 release, the HDF4 handler has been part of the Hyrax BES. No seperate download is necessary. Check the latest Hyrax
release and RPMs that includes the HDF4 handler at
OPeNDAP website.
For the backward compatibility, we still keep the old source code release that comes with the Hyrax 1.9.7 here
(SHA256:eadafd3f601fddd128837dd76e971e5e30cd9fbebd3d1fbf51bf92337528cba2). At some point in the future,
this will be removed.
Since the Hyrax 1.13.2 release, the Hyrax team has provided one BES RPM that includes the HDF4 handler in their release distribution.
No HDF4 handler RPM is needed to be installed. Check the latest Hyrax
release and RPMs that includes the HDF4 handler module at
OPeNDAP website.
Since the HDF4 handler is a module in the Hyrax' BES package, people need to build the whole BES from source. Hyrax' team provides information on how to build Hyrax from the source here.
Please check the usage document.
For a comprehensive product list that the HDF4 OPeNDAP handler supports and a collection of screenshots generated from various OPeNDAP client visualization tools such as IDV and Panoply, please click sample demo and screenshots.
We provide a document on how different BES keys are used to tune in performance and other features for the handler. This may be especially useful for NASA data centers that may need to choose different key values for their specific usage. Please check the BES-keys-for-H4-handler.
Search the [Known Issues] here for limitations and known problems.
