Provided by: grass-doc_7.8.2-1build3_all bug


       i.landsat.acca  - Performs Landsat TM/ETM+ Automatic Cloud Cover Assessment (ACCA).


       imagery, ACCA, cloud detection, satellite, Landsat


       i.landsat.acca --help
       i.landsat.acca      [-5fx2s]      input=basename     output=name      [b56composite=float]
       [b45ratio=float]   [histogram=integer]   [--overwrite]  [--help]   [--verbose]   [--quiet]

           Data is Landsat-5 TM
           I.e. Thermal band is ’.6’ not ’.61’)

           Apply post-processing filter to remove small holes

           Always use cloud signature (step 14)

           Bypass second-pass processing, and merge warm (not ambiguous) and cold clouds

           Include a category for cloud shadows

           Allow output files to overwrite existing files

           Print usage summary

           Verbose module output

           Quiet module output

           Force launching GUI dialog

       input=basename [required]
           Base name of input raster bands
           Example: ’B.’ for B.1, B.2, ...

       output=name [required]
           Name for output raster map

           B56composite (step 6)
           Default: 225.

           B45ratio: Desert detection (step 10)
           Default: 1.

           Number of classes in the cloud temperature histogram
           Default: 100


       i.landsat.acca implements the Automated Cloud-Cover Assessment (ACCA) Algorithm from Irish
       (2000) with the constant values for pass filter one from Irish et al. (2006). To do  this,
       it needs Landsat band numbers 2, 3, 4, 5, and 6 (or band 61 for Landsat-7 ETM+) which have
       already  been  processed  from  DN  into   reflectance   and   band-6   temperature   with

       The  ACCA  algorithm  gives good results over most of the planet with the exception of ice
       sheets because ACCA operates on the premise that clouds are colder than the  land  surface
       they  cover. The algorithm was designed for Landsat-7 ETM+ but because reflectance is used
       it is also useful for Landsat-4/5 TM.


       i.landsat.acca works in the current region settings.


       Run the standard ACCA algorithm with filling of small cloud  holes  (the  -f  flag):  With
       per-band  reflectance raster maps named 226_62.toar.1, 226_62.toar.2,  [...] and LANDSAT-7
       thermal band 226_62.toar.61, outputting to a new raster map named 226_62.acca:
       i.landsat.toar sensor=7 gain=HHHLHLHHL date=2003-04-07 \
         product_date=2008-11-27 band_prefix=226_62 solar_elevation=49.51654
       i.landsat.acca -f band_prefix=226_62.toar output=226_62.acca


       1      Irish R.R., Barker J.L., Goward S.N., and Arvidson T., 2006.   Characterization  of
              the   Landsat-7   ETM+   Automated   Cloud-Cover   Assessment   (ACCA)   Algorithm.
              Photogrammetric Engineering and Remote Sensing vol. 72(10): 1179-1188.

       2      Irish, R.R., 2000. Landsat 7 Automatic Cloud Cover Assessment.  In  S.S.  Shen  and
              M.R. Descour (Eds.): Algorithms for Multispectral, Hyperspectral, and Ultraspectral
              Imagery VI. Proceedings of SPIE, 4049: 348-355.


        i.atcorr, i.landsat.toar


       E. Jorge Tizado  (ej.tizado unileon es), Dept. Biodiversity and Environmental  Management,
       University of León, Spain


       Available at: i.landsat.acca source code (history)

       Main index | Imagery index | Topics index | Keywords index | Graphical index | Full index

       © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual