First, elevation is not a part of the work involved in getting coordinates
into the authority records for places, so don't worry about that. As it is
the only way we as catalogers record elevation is through a note about how
relief and/or depth features are shown, we've never been responsible for
providing specific elevation points or their accuracy. I think someone on
MAPS-L also eluded to this the other day and I failed to reply.
What we are after is identifying the geographical location of a place on
the Earth's surface via a set of coordinates, and what has been proposed is
that this can be done as a bounding box, as X,Y point coordinates, or as a
polygon. This is the same as what we are able to provide in the MARC format
for bibliographic records so their is nothing new here. As to the accuracy
of a set of coordinates, of course that depends on the source and I believe
(Colleen, help me out here) that we are going to rely on data primarily
from trusted sources such as GNIS and GEOnet, but also are gathering
datasets from ESRI and other like institutions. If coordinate values vary
that much from one type of GPS unit to the other (I find that a bit
surprising since these units are downloading information from the same
satellites, is that right?) then perhaps using coordinates from actual
paper maps is still more important or accurate of a resource than these
GPS's, but that is speculation on my part. Accuracy is certainly important
for this data, but I wouldn't put the onus of testing said accuracy on
catalogers, they are going to want to simply use the authority record and
trust that it is accurate for most purposes. And perhaps thats the bottom
line, how the item is eventually used, for even with paper maps the level
of accuracy known and/or needed depends on the use that the map will be put
to by the patron. If the majority of the coordinate data comes from
already-trusted sources such as the Board on Geographic Names then perhaps
the accuracy issue will not be that big of a headache?
Paige
At 09:42 AM 7/3/2006, Joe Aufmuth wrote:
>If we're going to use GPS for authority records, what level of accuracy
>will be acceptable? Will there be a standardized method of
>collection? Typical handheld "walmart" receivers greatly vary in their
>measurements. Elevations in particular can be quite poor. So, who will
>be generating the authority records and the subsequent coordinates and
>elevations? Surveyors? GNIS? NGA? Catalogers? Who will be testing the
>accuracy of the coordinates used?
>
>Joe
>
>Joe Aufmuth
>GIS coordinator
>George A. Smathers Libraries
>Government Documents
>University of Florida
>P.O. Box 117001
>Gainesville, Florida 32611-7001
>352-273-0367
>Fax: 352-392-3357
>[log in to unmask] <mailto:[log in to unmask]>
>
>
>
>
>
>-----Original Message-----
>From: Subject Coordinates Discussion List [mailto:[log in to unmask]]On
>Behalf Of Dean C Rogers
>Sent: Friday, June 30, 2006 11:20 AM
>To: [log in to unmask]
>Subject: Re: [SUBCOOR] The proposal passed MARBI!
>
>
>Yes, great. And since GPS includes elevation, so will the authority
>records, right? (I hope).
>
>Dean Rogers
>Map Cataloger
>Library
>U.S. Geological Survey
>Reston, Va.
>
>
>
>"Houghton,Andrew" <[log in to unmask]>
>Sent by: Subject Coordinates Discussion List <[log in to unmask]>
>06/30/2006 07:49 AM
>Please respond to
>Subject Coordinates Discussion List <[log in to unmask]>
>
>
>To
>[log in to unmask]
>cc
>
>Subject
>Re: The proposal passed MARBI!
>
>
>
>
>
>
> > From: Subject Coordinates Discussion List
> > [mailto:[log in to unmask]] On Behalf Of Colleen R. Cahill
> > Sent: 30 June, 2006 07:15
> > To: [log in to unmask]
> > Subject: [SUBCOOR] The proposal passed MARBI!
> >
> > We now face some choices, primarly in what format we want the
> > coordinates to appear in authority records. This can be
> > either degrees, minutes, seconds or decimal degrees: both
> > have advantages and disadvantages. Here are a few I have
> > thought of and am hoping for your input:
> >
> > Degrees, minutes, seconds format
> > Pro:
> > -Format most often printed on maps
> > -Familiar to most people
> > -Easy to quality review
> > -Format most often used in bib records
> >
> > Con:
> > -Not format used by GIS search engines
> >
> > Decimal Degrees
> > Pro:
> > -Format used by GIS search engines
> > -Can harvest data from GIS tools
> >
> > Con:
> > -Not as easy to quality review
> > -Not as familiar a format to the average person
>
>Handheld GPS devices can output either format and output from
>the GPS device may be used to create local authority records.
>In addition, the conversion between decimal degrees and DMS
>is trivial. If the catalog uses decimal degrees, it can be
>easily converted to DMS for user friendly displays. This
>point negates Con(2) under Decimal Degrees.
>
>I'm not throwing my two cents either way, just providing a
>few additional thoughts. So long as the data is in its own
>subfield and it doesn't need to be parsed out of other textual
>data, then either format can be used effectively.
>
>
>Andy.
