Sounds good to me, I prefer E and W to 360 deg. Roger ******************************************************************************* Dr. Roger G. Barry Professor of Geography and Director, National Snow and Ice Data Center (NSIDC) and World Data Center (WDC) for Glaciology, Boulder CIRES/NSIDC University of Colorado Phone: (303) 492-5488 Campus Box 449 FAX: (303) 492-2468 Boulder, CO 80309 E-mail: rbarry@kryos.colorado.edu ******************************************************************************* On Wed, 12 Jun 2002, Bruce Raup wrote:
Hi all,
In addition to messages pointing out my north-south mistake, I got some feedback (much of it from Hugh Kieffer) on GLIMS glacier IDs:
1. It was thought that having a flexible number of digits to the right of the implied decimal place could lead to confusion. Thus, leaving it at 3 digits was recommended.
2. It was pointed out that the underscore is unneeded.
3. There was a preference for having the E/W, N/S designators *follow* their corresponding numbers.
4. The original specification called for only east longitudes, in the range of [0,360). Luke Copland stated that using west longitudes for his area was easier. If we allow W or E longitudes to be used, then we must allow longitudes only in the range (-180,180]. Otherwise, we could get two IDs in the western hemisphere that point to the same place on the ground, but that would be distinct IDs (e.g. G050000W040000N and G310000E040000N).
Reminder: the rationale for having the lon/lat encoded in the glacier ID is so that Regional Centers can generate unique IDs without having to consult with anyone else (like, e.g. querying the database for the next available ID).
So, I propose an ID format as follows:
Gdddddd[W|E]ddddd[N|S]
There are 3 digits to the right of the implied decimal place. [W|E] means either W or E. Longitudes must be in the range [0,180], with W or E designating hemisphere. Latitudes range [0,90]. As an example, if there were a glacier where NSIDC is, it would have the ID "G105253W040013N".
IS THIS OKAY WITH EVERYONE?
Thanks, Bruce
-- Bruce Raup National Snow and Ice Data Center Phone: 303-492-8814 University of Colorado, 449 UCB Fax: 303-492-2468 Boulder, CO 80309-0449 braup@nsidc.org