[GRASS-dev] Added i.landsat8.swlst in grass-addons
Stefan.Blumentrath at nina.no
Wed May 11 03:22:48 PDT 2016
I just pushed a new addon ("i.landsat8.qc") to addons svn.
i.landsat8.qc reclassifies Landsat8 QA band according to a user defined filter for bit pattern representing unacceptable quality pixels. It implements basically the procedure mentioned below...
Any feedback is welcome...
From: grass-dev [mailto:grass-dev-bounces at lists.osgeo.org] On Behalf Of Blumentrath, Stefan
Sent: 10. mai 2016 09:57
To: Nikos Alexandris <nikos.alexandris at unige.ch>; Vaclav Petras <wenzeslaus at gmail.com>
Cc: grass-dev at lists.osgeo.org
Subject: Re: [GRASS-dev] Added i.landsat8.swlst in grass-addons
Another issue I came across it that currently, a possibly existing user mask will be simply overwritten, while it might be more friendly to backup the user mask before and restore it after the module finished... However, in order to simplify the module a bit, an option might be to move the masking part out of the module, and probably write something like this: https://grass.osgeo.org/grass70/manuals/i.modis.qc.html for Landsat, if that does not exist yet(?). Seems you thought about it already?
Based on Markus tutorial (http://courses.neteler.org/processing-landsat8-data-in-grass-gis-7/#Applying_the_Landsat_8_Quality_Assessment_%28QA%29_Band) and the info here http://landsat.usgs.gov/qualityband.php that should be a quite doable job. If no landsat bitpattern module exists I might be able to volunteer...
The idea would be something like this: extract raster values from QA band, loop over those values, compare the bit pattern representation of the integer values with acceptable bit patterns defined by the user, add the result of the comparison to r.reclass rules, and finally reclassify the QA band...
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