GLIMSters: All feedback I received (from 7 or 8 people) regarding storing only lon/lat coordinates in the GLIMS database was generally positive. So, while we've been proceeding in this direction already for several weeks now, I would like to state clearly on this list that this has been firmly decided. Notes: 1. RCs will do (or are doing) their analyses in the projection of their choosing. Only final results to be submitted to NSIDC need be converted to longitude/latitude on the WGS84 datum. 2. It can be (and, indeed, has been) shown that the difference between interpolation between polygon points in a projection versus along a great circle is negligible for GLIMS applications. 3. Both local (relative, or within-image) and global (absolute geodetic) uncertainties will be stored for each polygon or segment. (The new data dictionary and Entity Relation Diagram will be on the website soon.) 4. GLIMS segments (parts of glacier outlines, centerlines, ELA lines, etc.) are linked to their source images in the database. Thus, if the geolocation of a source image is improved upon, the positions of segments derived from this image (and their uncertainties) can be updated. 5. Having made this decision, the parts of the database design that dealt with reference points, coordinate system definitions, etc. have been removed. 6. As has been noted before, there is good and freely available software for doing coordinate transformations. Examples include: Proj.4 - Cartographic Projections Library (http://www.remotesensing.org/proj/). This includes utilities for doing batch-oriented or interactive coordinate transformations, including datum shifts. Generic Mapping Tools (http://gmt.soest.hawaii.edu/) Cheers to all, 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