Hers's the spec for geotiff version 1. (click on the table of contents). Perhaps it will be useful to DCG. http://www.remotesensing.org/geotiff/spec/geotiffhome.html I noticed that the link to this forum's backpage is still not working so . . . Digging out Tiffer will take a bit more time - I have to remember how to work with html in angelfire again. Something for tommorrow evening. nice speaking with you, -TJ