Georeferencing of collecting localities

[Stan Blum]

At 04:39 PM 4/10/03 -0600, Mary Barkworth wrote:
>Out of great curiosity - and even greater ignorance - how much
>difference does use of different datums create? Are we talking
>centimeters, meters, kilometres? Does it vary with latitude and/or
>longitude?

Many of these issues been discussed, in the context of retrospectively
georeferencing collecting localities, by John Wieczorek for the MaNIS project:

http://elib.cs.berkeley.edu/manis/GeorefGuide.html

Has a good list of references at the end, and a map how much one can be off
(worst case) if you combine things based on different datums.  It gets
worse the further you get from where each datum is most accurate.  Maps of
Hawaii based on NAD27 are pretty different from what you'd get with WGS84

-Stan

Stanley D. Blum, Ph.D.
Research Information Manager
California Academy of Sciences
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