latitude and longitude designation and collection data

Doug Yanega dyanega at DENR1.IGIS.UIUC.EDU
Fri Sep 29 21:24:03 CDT 1995

>          The California Academy of Sciences has recently acquired
>          GIS software.  It is of great interest to us to use this
>          software in conjunction with our existing collection's data.
>          However, much of our existing data is without latitudinal
>          and longitudinal designations.  Has anyone already
>          undertaken the huge job of retrospectively assigning
>          latitude and longitude to their collections data.  If so,
>          what was done to maximize the speed and accuracy of the job?

I've been keeping my eyes peeled for something that would do the trick, but
so far have heard nothing more than rumors, or half-baked solutions. The
objective, and the ideal method of obtaining it seem easy enough to
formulate: start with a very detailed geographic map, with both roads AND
topographic information, and then apply software which tells you exactly
what the latitude, longitude, and altitude are at the point of the cursor,
and lets you measure distances along roads. This *must* be feasible with
present technology, but *is* there extant software that has both that
"where is the cursor" feature AND a distance scale that can track curved
lines? For example, if one has a label that says "MEXICO: Queretaro, 13 km
W Xilitla", and the road is some winding mountain affair with switchbacks,
13 road kilometers may be VERY different from 13 linear kilometers (and due
West may be very different from where the road goes), and in areas of such
high topographic relief, a tiny difference on the map could make a
tremendous difference in altitude and habitat. Having just the "point and
click" ability is nice, and might serve for cases where (1) roads are
perfectly straight, (2) the margin for error does NOT take you into
different altitudes or habitats, or (3) the locality was a town. But if the
program can't also handle that specialized road-distance requirement, it's
going to be very tough to get accurate locality data back for a good many

Doug Yanega       Illinois Natural History Survey, 607 E. Peabody Dr.
Champaign, IL 61820 USA      phone (217) 244-6817, fax (217) 333-4949
 affiliate, Univ. of Illinois Urbana-Champaign, Dept. of Entomology
  "There are some enterprises in which a careful disorderliness
        is the true method" - Herman Melville, Moby Dick, Chap. 82

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