GLIMS Update... ASTER SWIR degradation

[Jeff Kargel]

Dear GLIMS colleagues,

This note is informational, and there is an action item, too.  

1.  Mike Abrams has been sending a stream of bad-news reports about the ASTER SWIR detectors.  The SWIR detectors are degrading rapidly as their temperature is increasing about 0.03 K/day, and already the longer bands are saturating at low latitudes over high albedo targets.  Band 4 will be the last to go, but we should not expect SWIR to last more than a few more months.  VNIR will continue to function, presumably, and since TIR has separate coolers, it will also presumably continue to function, though the entire system is well past its warranty.

2.  Have you been checking the successes of imaging over your areas since the new STARS were implemented?  Hopefully it's working well in your region, with the right gain settings, and some cloud-free acquisitions; I expect a lot of cloudy scenes, too, given the way the STARS are defined.  If you are having troubles with acquisitions, let me know.  And give me DARs (center lats/lons/image requirements; or polygon boundaries) if you have high priority scenes you need.  We cannolt overdo the DARs, but let's make sure your high priority areas are covered with one final year of SWIR.

--Jeff Kargel