---------- Forwarded message ----------
Date: Fri, 20 Aug 1999 07:44:23 -0500
From: Charles Hickman <[log in to unmask]>
To: [log in to unmask]
Cc: [log in to unmask]
Subject: re: indexing digital geographic data (was: NTIS and the rebellion)
>>> posted for Doug Nebert <[log in to unmask]> 08/19 7:51 PM >>>
The National Geospatial Data Clearinghouse is a federated collection
of over 100 servers containing descriptions of geospatial information
from governmental, commercial, academic, and other sources. The
Clearinghouse provides forms for a single point of search that can
query some or all of the Clearinghouse Nodes, returning formal
descriptions generally in the form of FGDC metadata, although some
sites in other countries return DIF and ANZLIC metadata entries.
The Clearinghouse is a free searchable resource with several
search interfaces at five regional gateways accessible through
the following URLs:
http://clearinghouse1.fgdc.gov
http://clearinghouse2.fgdc.gov
Doug Nebert
FGDC Clearinghouse
> ---------- Forwarded message ----------
> Date: Thu, 19 Aug 1999 09:51:50 -0500
> From: Pat Antrim <[log in to unmask]>
> To: Maps and Air Photo Systems Forum <[log in to unmask]>
> Subject: Re: indexing digital geographid data (was: NTIS and the rebellion)
>
> Doug, I'm kind of new to the list. Where can we find out
> more about this Clearinghouse project? Do members of
> this list use the Clearinghouse now? How?
>
> Pat
>
> --
> Patricia Antrim, Government Documents Librarian
> James C. Kirkpatrick Library
> Central Missouri State University, Warrensburg, MO 64093
> Voice: 660/543-8515 FAX: 660/543-8001
> mailto: [log in to unmask]
> http://library.cmsu.edu/paa/homepage.htm
>
> > ---------- Forwarded message ----------
> > Date: Wed, 18 Aug 1999 16:06:49 -0500
> > From: Charles Hickman <[log in to unmask]>
> > To: [log in to unmask]
> > Cc: [log in to unmask]
> > Subject: indexing digital geographid data (was: NTIS and the rebellion)
> >
> > >>> Posted to MAPS-L for
> > >>> Doug Nebert <[log in to unmask]> 08/18 2:40 PM >>>
> >
> > > Date: Mon, 16 Aug 1999 13:57:43 -0600
> > > From: Bill Thoen <[log in to unmask]>
> > > To: Maps and Air Photo Systems Forum <[log in to unmask]>
> > > Subject: Re: NTIS and the Rebellion...
> > >
> > > Actually, I suspect that continuing development of search engines
> > > will do more to revolutionize how libraries index information
> > > than the other way around.
> > >
> >
> > I agree completely with Bill that unstructured, document-like
> > information has a great promise for discovery through emerging
> > search engines. The challenges for indexing digital geographic data
> > however have not yet been met by existing search engines without
> > some help. We are helping to overturn some of these problems
> > with commercial vendors, but the following obstacles remain:
> >
> > Formalization of spatial and temporal tags. Sure, place names
> > can be found in documents and metadata, but unless they are done
> > with some intelligence or known classification system, the search
> > and matching of results is very problematic yielding many possible
> > matches that one must wade through. Fortunately FGDC metadata
> > includes dates and bounding coordinates that can be easily
> > parsed from the XML representation of the metadata into unambiguous
> > locations. Good metadata collection and search tools also hide
> > the management of these numeric coordinates behind place name pick
> > lists or map-based selectors that derive coordinates on the back
> > end.
> >
> > Management of large collections. Many of the richest and deepest
> > collections of geospatial data products store their metadata in
> > relational databases. With millions of entries it is not very
> > smart to export and synchronize the entire collection with an
> > XML or HTML form to be visited by search engines. In these cases
> > the product series metadata might get exposed for search but the
> > details that get the user to accessing a specific product are
> > still hidden from view. I see great potential in combining search
> > engines within every website that are threaded into any local
> > data bases to provide rapid local discovery. I see indications
> > that Microsoft and Oracle are heading this way, making the
> > possibility of a targeted distributed search a real possibility.
> > Site "centroids" or descriptive records end up getting exposed
> > to crawlers and search engines. Searches then are passed only
> > to site indexes that match a certain profile where current public
> > content is searched. We are still a year or two away from this
> > vision that can only work reliably with some search standards
> > in place. Perhaps the OpenGIS Consortium's Catalog Services
> > specification, passed last week can help out here.
> >
> > Links between data and metadata. I agree that the traditional
> > external catalog model is outdated. In the digital world the
> > data and the metadata should become one. Metadata are simply
> > the properties returned from querying a data object. In the
> > not too distant future when one places a spatial data object
> > into the public database, it properties become the things
> > against which searches are posed. Software uses them; nice
> > user presentations of the metadata can be made from them. But
> > again we are still far from having commercial search
> > engines recognize existing spatial data structures let alone
> > spatial data with embedded metadata.
> >
> > In the next year we will be revisiting the potential of the
> > centralized and distributed elements of Clearinghouse to better
> > achieve the vision of spatial data discovery and access. And
> > we will be doing so with the leverage of emerging standards
> > and commercial search technology. I hope to make the use of
> > the Clearinghouse potentially a transparent one that your GIS
> > software could just use programmatically to help get your job
> > done. Other browseable interfaces will lead GIS-naive users
> > from finding a map, past needing to interpret complex metadata,
> > and will present them the picture that they are seeking in
> > response to a problem. New solutions are looming on the horizon
> > with open, interoperable web mapping interfaces from the OpenGIS
> > Consortium with support from all the major (and some minor)
> > GIS vendors. Big changes are afoot!
> >
> > Doug Nebert
> > FGDC
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