An HDF-EOS Data Server Based on OPeNDAP and ECHO Bob Bane, Mohammad Rabi, Weijun Su, Richard Ullman, Jingli Yang, Zhangshi Yin Data Usability Group, NASA/GSFC

HDF-EOS data access via web Findable –With standard search engines –With domain-specific engines Browseable –Per-granule web page Readable metadata Links for fetching data Retrievable –Whole dataset –Metadata only –Individual fields –Sectorized fields

Intended Audience Groups that are generating HDF-EOS products Need a straightforward, inexpensive way to publish them to the web Major archives already have their own systems - this is for everyone else

Tools used Standard tools –Unix shell scripts –Apache web server Earth science standards and protocols –OPeNDAP –ECHO Our tools –ODL XML HTML

OPeNDAP “netCDF via HTTP” Also works for HDF 4/5 and HDF-EOS 2/5

ECHO EOS ClearingHouse Searchable repository for earth science metadata Based on standard commercial tools –Databases –E-commerce middleware

Our Tools hemu - extracts ODL metadata odl2xml - converts ODL to EOS- compatible XML heex - breaks an HDF-EOS dataset into field files with an HTML/XML table of contents XSLT stylesheets - convert XML to pretty HTML

HDF_EOS files hemuheex ODL metadata odl2xml XML metadata XSLT Pretty HTML Field files OPeNDAP server Web server ECHO server ECHO XML Search/query Browse/fetch Fetch/sectorize DODS client Web browser ECHO client File transfer Web/HTTP Search engines Implemented by usOther toolsClient-side services XML contents

Installation Foundation –Unix –Apache –Java Libraries –HDF4/5, HDF-EOS2/5 –SDP Toolkit –OPeNDAP server Our software –heex, odl2xml, hemu –heserve scripts

Use Two shell scripts –ingest granule-file.hdf Publishes granule to the web –echoingest metadata.xml Publishes web links for granule to ECHO Optionally called by ingest

Granule Web Pages

Screen shot Showing link dragged into DODS client

Where is the software? ’Tools’ link heserve system