1i.landsat.acca(1) GRASS GIS User's Manual i.landsat.acca(1)
2
6 i.landsat.acca - Performs Landsat TM/ETM+ Automatic Cloud Cover As‐
7 sessment (ACCA).
8
10 imagery, ACCA, cloud detection, satellite, Landsat
11
13 i.landsat.acca
14 i.landsat.acca --help
15 i.landsat.acca [-5fx2s] input=basename output=name [b56compos‐
16 ite=float] [b45ratio=float] [histogram=integer] [--overwrite]
17 [--help] [--verbose] [--quiet] [--ui]
18 Flags:
20 -5
21 Data is Landsat-5 TM
22 I.e. Thermal band is ’.6’ not ’.61’)
23 -f
25 Apply post-processing filter to remove small holes
26 -x
28 Always use cloud signature (step 14)
29 -2
31 Bypass second-pass processing, and merge warm (not ambiguous) and
32 cold clouds
33 -s
35 Include a category for cloud shadows
36 --overwrite
38 Allow output files to overwrite existing files
39 --help
41 Print usage summary
42 --verbose
44 Verbose module output
45 --quiet
47 Quiet module output
48 --ui
50 Force launching GUI dialog
51 Parameters:
53 input=basename [required]
54 Base name of input raster bands
55 Example: ’B.’ for B.1, B.2, ...
56 output=name [required]
58 Name for output raster map
59 b56composite=float
61 B56composite (step 6)
62 Default: 225.
63 b45ratio=float
65 B45ratio: Desert detection (step 10)
66 Default: 1.
67 histogram=integer
69 Number of classes in the cloud temperature histogram
70 Default: 100
71
73 i.landsat.acca implements the Automated Cloud-Cover Assessment (ACCA)
74 Algorithm from Irish (2000) with the constant values for pass filter
75 one from Irish et al. (2006). To do this, it needs Landsat band numbers
76 2, 3, 4, 5, and 6 (or band 61 for Landsat-7 ETM+) which have already
77 been processed from DN into reflectance and band-6 temperature with
78 i.landsat.toar).
79 The ACCA algorithm gives good results over most of the planet with the
81 exception of ice sheets because ACCA operates on the premise that
82 clouds are colder than the land surface they cover. The algorithm was
83 designed for Landsat-7 ETM+ but because reflectance is used it is also
84 useful for Landsat-4/5 TM.
85
87 i.landsat.acca works in the current region settings.
88
90 Run the standard ACCA algorithm with filling of small cloud holes (the
91 -f flag): With per-band reflectance raster maps named 226_62.toar.1,
92 226_62.toar.2, [...] and LANDSAT-7 thermal band 226_62.toar.61, out‐
93 putting to a new raster map named 226_62.acca:
94 i.landsat.toar sensor=7 gain=HHHLHLHHL date=2003-04-07 \
95 product_date=2008-11-27 band_prefix=226_62 solar_elevation=49.51654
96 i.landsat.acca -f band_prefix=226_62.toar output=226_62.acca
97
99 1 Irish R.R., Barker J.L., Goward S.N., and Arvidson T., 2006.
100 Characterization of the Landsat-7 ETM+ Automated Cloud-Cover As‐
101 sessment (ACCA) Algorithm. Photogrammetric Engineering and Re‐
102 mote Sensing vol. 72(10): 1179-1188.
103 2 Irish, R.R., 2000. Landsat 7 Automatic Cloud Cover Assessment.
105 In S.S. Shen and M.R. Descour (Eds.): Algorithms for Multispec‐
106 tral, Hyperspectral, and Ultraspectral Imagery VI. Proceedings
107 of SPIE, 4049: 348-355.
108
110 i.atcorr, i.landsat.toar
111
113 E. Jorge Tizado (ej.tizado unileon es), Dept. Biodiversity and Envi‐
114 ronmental Management, University of León, Spain
115
117 Available at: i.landsat.acca source code (history)
118 Accessed: Mon Jun 20 16:47:30 2022
120 Main index | Imagery index | Topics index | Keywords index | Graphical
122 index | Full index
123 © 2003-2022 GRASS Development Team, GRASS GIS 8.2.0 Reference Manual
125GRASS 8.2.0 i.landsat.acca(1)