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Ticket Resolution Summary Owner Reporter
#74 fixed Support: 16/Oct/2007, Rachel Gaulton/Tim Malthus, GB06/05 benj mggr
Description

Rachel contacted us with a problem relating to radiometric calibration.

I'm not sure who specifically is the best person to ask about this,
but I am having some problems with the AISA Eagle data recently
delivered for my sites (Clocaenog and Glasfynydd, acquired July 06).
The radiance values differ considerably to those of the CASI and ATM
data acquired at the same time, specifically they are much lower
(about 1/2 to 2/3) in the Eagle data (see attached spectra of a paved
area in Glasfynydd for an example).  Following attempts at atmospheric
correction, this results in significantly lower reflectance than is
expected based on ground spectra.  I  may be missing something obvious
(e.g. different units), or is this down to errors in the radiometric
calibration of the Eagle sensor?
#38 fixed Support: 16/July/2007, Richard Teeuw (+Chris Hecker), WM mggr mggr
Description

Richard contacted Gary with a query regarding azgcorr versions (expired again). Noted website was out of date too.

#128 fixed Support: 16/Apr/2008, Jon Atherton, (no project code) mggr benj
Description

Had a request for help from a user of existing CASI data (Jon Atherton) who was not an original PI but obtained some 2005 flight data from NEODC:

Hello,

I'm a complete novice at preprocessing CASI data. I have access to the NEODC online data sets, and I would like to use CASI data from Sitia, 2005 (http://neodc.nerc.ac.uk/cgi-infrastructure/data_browser/data_browser/neodc/arsf/2005/MC04_15).
I need about 15 bands worth centred at 685 nm (band 32 to 47) from images c130021b and c130041b.

Your colleague (Gary Llewellyn) kindly provided me with the FTP for AZGCORR. I had a go with the basic line of code (provided in the tutorial) which produced a blurred image on an angle, when compared with the three bands-worth of images already processed to level 3b which are available online. Any help on correcting the blurriness would be greatly appreciated.

The only code I used was (I don't have a DEM):

 "./azcor -bl 1 -1 -p 2.0 2.5 -1 c130021b.hdf -3 c130023a.hdf"


Best wishes,

Jon Atherton

PhD student
University of Edinburgh

Replied to the query (suggested he applied a correct projection, used square pixels and tried some different bands), which seems to have solved the problem.

What if any support level should we be providing to new users of existing data? On the one hand we don't want to leave ourselves open to potentially large open-ended support requests from non-PIs, on the other it's in our interests to have ARSF data as widely available and used as possible.

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