Date:         Wed, 7 Sep 2005 10:20:15 -0700
Reply-To:     [log in to unmask]
Sender:       Subject Coordinates Discussion List <[log in to unmask]>
From:         Mary Larsgaard <[log in to unmask]>
Organization: UCSB Map & Imagery Lab, Library
Subject:      Re: batch insertion of coordinates  into catalog records
Comments: To: Subject Coordinates Discussion List <[log in to unmask]>
In-Reply-To:  <[log in to unmask]>
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My very limited information on this point is
that it's the batch lookup and insertion that's
difficult, although there are certainly other challenges.
For example, we have a couple
of text files that have a geographic area and
then the bounding-box coordinates:
- states of U.S.
- counties of U.S.
- nations of the world

One would have to make sure date of
data in the cartographic item matched the
date of coordinates in the lists (basically
1980s or thereabouts).
And you'd have to find a way to kick
out, say, cartographic items with pre-1900
data (ok when that's the date of publication;
more difficult by a good bit when there's
an, e.g., 20th-cent date of pub but a pre-1900
date of data. If cataloger didn't use the MARC21
date-of-data field, 045, time period of content,
then it's real difficult), to match correct
bounding boxes with political area at
a given date.

So in theory, one could group one's
catalog records by the geographic
areas in the subject headings (but you'd
have to figure out a way where a record
with multiple geographic-area subject headings
could have copies in each group),
and then match against these text files,
and then move the bounding box coordinates
appropriate to the record into MARC21 |d,e,f and g.

You'd also have to have a way to separate
out those geog-area subject headings that
weren't states, counties, natons - which would
probably leave:
- cities; could match those against world
gazetteer's cities entries; we'd probably use
the Alexandria Digital Library's Gazetteer
http://middleware.alexandria.ucsb.edu/client/gaz/adl/index.jsp

- other political areas (e.g., provinces of Canada;
states of Australia): I've got a list of coords for
Canadian provinces and there are probably lists
out there for other political areas of nation's countries

- non-polit areas, e.g., "Denver-Julesburg Basin";
these would be the most difficult since there aren't
any firm boundaries as there are for political areas.

Am sure I'm forgetting some of the other "challenges"...
Mary


Archie Warnock wrote:

>Mary Larsgaard wrote:
>  
>
>>**yes indeedy. I remember a couple years back, a friend of mine who
>>was cataloging photographs of portions of a city was going to enter
>>coordinates into each record, unwisely mentioned that to someone at
>>one of the utilities, who told her no-no, can't enter coordinates for
>>non-cart.mtls. one experiment we'd like to do here at UCSB is
>>download all of the non-cartmtl records in the library's online
>>catalog, pull out all the ones that have geographic-area subject
>>headings (which MARC21 makes very do-able), and then add coordinates
>>to each record (that's the tricky part), and load records into
>>Alexandria Digital Library catalog.
>>    
>>
>
>Somewhere around here I had some code that I'd glommed to compute the
>minimum bounding rectangle (MBR) from a polygonal footprint.  That
>simplifies the job to the point where it's relatively easy to do spatial
>searching.
>
>For some time, I've maintained the search engine (Isearch) used on FGDC
>metadata records and it does spatial searches (overlaps only, but
>relevance ranked) on bounding rectangles, although it doesn't currently
>compute the MBR from more complex polygons.  It's not real MARC-aware
>either, but that could be fixed.
>
>I'm curious where the coordinates might come from because obviously this
>is a job that ought to be automated.  Are there any easily-available
>online gazetteers that will provide coordinates from place names which
>would allow batch-insertion of geographic coordinates?
>
>  
>