Quoting Jeff Kargel <jkargel1054@earthlink.net>:
Dear GLIMS colleagues,
YOUR COMMENTS AND SUGGESTIONS ARE NEEDED.
Greetings Jeff: Our e-mail system isn't rendering your first message correctly, "returned images having 3/410% clouds." Should this be greater than or less than? I've found that images with less than 35% cloud cover frequently have some useful parts but realistically less than 25% are the most useful. With this in mind herewith some numbers for Svalbard and Franz Josef Land gathered from LPDAAC this morning. Svalbard: Search box: 9E to 24E, 76N to 81N Period: 2005-04-01 to 2005-09-30 Day & Night L1A....673 images...519 with cloud cover equal to or greater than 35%....154 with less than 35% L1B....17 images...4 of those 17 are of only the ocean so only 13 include some land ice Franz Josef Land: Search box: 45E to 65E, 80N to 82N Period: 2005-04-01 to 2005-09-30 Day & Night L1A....295 images...211 with cloud cover equal to or greater than 35%....84 with less than 35% L1B....18 images ________________________________________________________ Here are some Svalbard numbers previously compiled for the years 2000 through and including 2004. The search box was slightly different, 10E to 34E and 76.5N to 81N. Period was July 01 through September 30 for each year and only Day images were recorded. The numbers are for L1B images only. "Usable" I defined as any image with less than 35% cloud cover and containing some small snippet of cloud-free land. 2000: 194 L1B images....20 usable 2001: 93 L1B images....40 usable 2002: 7 L1B images....7 usable 2003: 17 L1B images....10 usable 2004: 16 L1B images....7 usable These numbers were compiled in June 2005 and I'm sure they haven't changed a bit. The availability of the Windows/DOS-based L1A-to-L1B conversion software has allowed us to use L1As from these year that will probably never get converted otherwise. However, I have no sense of what those numbers might be. I've recently been collecting 2000-2004 L1B images of Franz Josef Land but haven't yet looked through them for "usable" images. I'll do so if it would be helpful. Finally, we are not overwhelmed with repeat coverage for large parts of Svalbard (the area I'm most familiar with). Finding 8 or 9 glaciers in the archipelago with 2 or more years of ASTER imagery for my thesis work has been a real chore. bill sneed graduate student climate change institute univ. of maine, orono