[GRASS-SVN] r47450 - grass-addons/grass7/imagery/i.topo.corr
svn_grass at osgeo.org
svn_grass at osgeo.org
Thu Aug 4 13:24:46 EDT 2011
Author: neteler
Date: 2011-08-04 10:24:46 -0700 (Thu, 04 Aug 2011)
New Revision: 47450
Added:
grass-addons/grass7/imagery/i.topo.corr/i.topo.corr.html
Removed:
grass-addons/grass7/imagery/i.topo.corr/description.html
Log:
almost ported to GRASS 7
Deleted: grass-addons/grass7/imagery/i.topo.corr/description.html
===================================================================
--- grass-addons/grass7/imagery/i.topo.corr/description.html 2011-08-04 17:23:41 UTC (rev 47449)
+++ grass-addons/grass7/imagery/i.topo.corr/description.html 2011-08-04 17:24:46 UTC (rev 47450)
@@ -1,116 +0,0 @@
-<H2>DESCRIPTION</H2>
-
-<p><EM>i.topo.corr</EM> is used to topographically correct reflectance
-from imagery files, e.g. obtained with <EM>i.landsat.toar</EM>, using a
-sun illumination terrain model. This illumination model represents the
-cosine of the incident angle, i.e. the angle between the normal to the
-ground and the sun rays. It can be obtained with <em>r.sun</em>
-(parameter incidout), and then calculating its cosine with float precision.</p>
-
-<p>Using flag -i and given an elevation map as basemap (UTM),
-<em>i.topo.corr</em> permits to obtain a simple illumination model from the formula:
-<ul>
- <li> cos_i = cos(s) * cos(z) + sin(s) * sin(z) * sin(a - o) </li>
-</ul>
-where,
-<em>s</em> is the terrain slope angle, <em>z</em> is the solar zenith angle,
-<em>a</em> the solar azimuth angle, <em>o</em> the terrain aspect angle.</p>
-
-<p>For each band file, the corrected reflectance (ref_c) is calculate from
-the original reflectance (ref_o) using one of the four offered methods
-<!-- TODO: fix next numbers -->
-(one lambertian and two non-lambertian).</p>
-
-<h3>Method: cosine</h3>
-
-<ul>
-<li> ref_c = ref_o * cos_z / cos_i </li>
-</ul>
-
-<h3>Method: minnaert</h3>
-
-<ul>
-<li>ref_c = ref_o * (cos_z / cos_i) ^k</li>
-</ul>
-where,
-<em>k</em> is obtained by linear regression of<br>
-ln(ref_o) = ln(ref_c) - k ln(cos_i/cos_z)
-
-<h3>Method: c-factor</h3>
-
-<ul>
-<li>ref_c = ref_o * (cos_z + c)/ (cos_i + c)</li>
-</ul>
-where,
-<em>c</em> is a/m from ref_o = a + m * cos_i
-
-<h3>Method: percent</h3>
-
-We can use cos_i to estimate the percent of solar incidence on the surface,
-then the transformation (cos_i + 1)/2 varied from 0
-(surface in the side in opposition to the sun: infinite correction) to 1
-(direct exhibition to the sun: no correction) and the corrected reflectance can
-be calculated as
-<ul>
-<li>ref_c = ref_o * 2 / (cos_i + 1)</li>
-</ul>
-
-<h2>NOTES</h2>
-
-<ol>
-<li>The illumination model (cos_i) with flag -i uses the actual region
- as limits and the resolution of the elevation map.</li>
-<li>The topographic correction use the full reflectance file (null remain
- null) and its resolution.</li>
-<li>The elevation map to calculate the illumination model should be metric.</li>
-</ol>
-
-<H2>EXAMPLES</H2>
-
-First, make a illumination model from the elevation map (here, SRTM), and
-then make topographic correction of the bands toar.5, toar.4 and toar.3 with
-output as tcor.toar.5, tcor.toar.4, and tcor.toar.3 using c-factor (= c-correction)
-method.
-<p>
-
-<div class="code"><pre>
-i.topo.corr -i base=SRTM zenith=33.3631 azimuth=59.8897 out=SRTM.illumination
-i.topo.corr base=SRTM.illumination input=toar.5,toar.4,toar.3 out=tcor \
- zenith=33.3631 method=c-factor
-</pre></div>
-
-<h2>REFERENCES</h2>
-
-<ul>
-<li>Law K.H. and Nichol J, 2004. Topographic Correction For Differential
- Illumination Effects On Ikonos Satellite Imagery. International Archives of
- Photogrammetry Remote Sensing and Spatial Information, pp. 641-646.</li>
-<li>Meyer, P. and Itten, K.I. and Kellenberger, KJ and Sandmeier, S. and
- Sandmeier, R., 1993. Radiometric corrections of topographically induced
- effects on Landsat TM data in alpine terrain. Photogrammetric Engineering
- and Remote Sensing 48(17).</li>
-<li>Riaño, D. and Chuvieco, E. and Salas, J. and Aguado, I., 2003.
- Assessment of Different Topographic Corrections in Landsat-TM
- Data for Mapping Vegetation Types. IEEE Transactions On Geoscience
- And Remote Sensing, Vol. 41, No. 5</li>
-<li>Twele A. and Erasmi S, 2005. Evaluating topographic correction algorithms
- for improved land cover discrimination in mountainous areas of
- Central Sulawesi. Göttinger Geographische Abhandlungen, vol. 113.</li>
-</ul>
-
-
-<h2>SEE ALSO</h2>
-
-<em>
-<A HREF="i.landsat.toar">i.landsat.toar</A>,
-<A HREF="r.mapcalc.html">r.mapcalc</A>,
-<A HREF="r.sun.html">r.sun</A>
-</em>
-
-<H2>AUTHOR</H2>
-
-E. Jorge Tizado (ej.tizado unileon es)<br>
-Dept. Biodiversity and Environmental Management, University of León, Spain
-
-<p>
-<i>Last changed: $Date$</i>
Copied: grass-addons/grass7/imagery/i.topo.corr/i.topo.corr.html (from rev 47449, grass-addons/grass7/imagery/i.topo.corr/description.html)
===================================================================
--- grass-addons/grass7/imagery/i.topo.corr/i.topo.corr.html (rev 0)
+++ grass-addons/grass7/imagery/i.topo.corr/i.topo.corr.html 2011-08-04 17:24:46 UTC (rev 47450)
@@ -0,0 +1,116 @@
+<H2>DESCRIPTION</H2>
+
+<p><EM>i.topo.corr</EM> is used to topographically correct reflectance
+from imagery files, e.g. obtained with <EM>i.landsat.toar</EM>, using a
+sun illumination terrain model. This illumination model represents the
+cosine of the incident angle, i.e. the angle between the normal to the
+ground and the sun rays. It can be obtained with <em>r.sun</em>
+(parameter incidout), and then calculating its cosine with float precision.</p>
+
+<p>Using flag -i and given an elevation map as basemap (UTM),
+<em>i.topo.corr</em> permits to obtain a simple illumination model from the formula:
+<ul>
+ <li> cos_i = cos(s) * cos(z) + sin(s) * sin(z) * sin(a - o) </li>
+</ul>
+where,
+<em>s</em> is the terrain slope angle, <em>z</em> is the solar zenith angle,
+<em>a</em> the solar azimuth angle, <em>o</em> the terrain aspect angle.</p>
+
+<p>For each band file, the corrected reflectance (ref_c) is calculate from
+the original reflectance (ref_o) using one of the four offered methods
+<!-- TODO: fix next numbers -->
+(one lambertian and two non-lambertian).</p>
+
+<h3>Method: cosine</h3>
+
+<ul>
+<li> ref_c = ref_o * cos_z / cos_i </li>
+</ul>
+
+<h3>Method: minnaert</h3>
+
+<ul>
+<li>ref_c = ref_o * (cos_z / cos_i) ^k</li>
+</ul>
+where,
+<em>k</em> is obtained by linear regression of<br>
+ln(ref_o) = ln(ref_c) - k ln(cos_i/cos_z)
+
+<h3>Method: c-factor</h3>
+
+<ul>
+<li>ref_c = ref_o * (cos_z + c)/ (cos_i + c)</li>
+</ul>
+where,
+<em>c</em> is a/m from ref_o = a + m * cos_i
+
+<h3>Method: percent</h3>
+
+We can use cos_i to estimate the percent of solar incidence on the surface,
+then the transformation (cos_i + 1)/2 varied from 0
+(surface in the side in opposition to the sun: infinite correction) to 1
+(direct exhibition to the sun: no correction) and the corrected reflectance can
+be calculated as
+<ul>
+<li>ref_c = ref_o * 2 / (cos_i + 1)</li>
+</ul>
+
+<h2>NOTES</h2>
+
+<ol>
+<li>The illumination model (cos_i) with flag -i uses the actual region
+ as limits and the resolution of the elevation map.</li>
+<li>The topographic correction use the full reflectance file (null remain
+ null) and its resolution.</li>
+<li>The elevation map to calculate the illumination model should be metric.</li>
+</ol>
+
+<H2>EXAMPLES</H2>
+
+First, make a illumination model from the elevation map (here, SRTM), and
+then make topographic correction of the bands toar.5, toar.4 and toar.3 with
+output as tcor.toar.5, tcor.toar.4, and tcor.toar.3 using c-factor (= c-correction)
+method.
+<p>
+
+<div class="code"><pre>
+i.topo.corr -i base=SRTM zenith=33.3631 azimuth=59.8897 out=SRTM.illumination
+i.topo.corr base=SRTM.illumination input=toar.5,toar.4,toar.3 out=tcor \
+ zenith=33.3631 method=c-factor
+</pre></div>
+
+<h2>REFERENCES</h2>
+
+<ul>
+<li>Law K.H. and Nichol J, 2004. Topographic Correction For Differential
+ Illumination Effects On Ikonos Satellite Imagery. International Archives of
+ Photogrammetry Remote Sensing and Spatial Information, pp. 641-646.</li>
+<li>Meyer, P. and Itten, K.I. and Kellenberger, KJ and Sandmeier, S. and
+ Sandmeier, R., 1993. Radiometric corrections of topographically induced
+ effects on Landsat TM data in alpine terrain. Photogrammetric Engineering
+ and Remote Sensing 48(17).</li>
+<li>Riaño, D. and Chuvieco, E. and Salas, J. and Aguado, I., 2003.
+ Assessment of Different Topographic Corrections in Landsat-TM
+ Data for Mapping Vegetation Types. IEEE Transactions On Geoscience
+ And Remote Sensing, Vol. 41, No. 5</li>
+<li>Twele A. and Erasmi S, 2005. Evaluating topographic correction algorithms
+ for improved land cover discrimination in mountainous areas of
+ Central Sulawesi. Göttinger Geographische Abhandlungen, vol. 113.</li>
+</ul>
+
+
+<h2>SEE ALSO</h2>
+
+<em>
+<A HREF="i.landsat.toar">i.landsat.toar</A>,
+<A HREF="r.mapcalc.html">r.mapcalc</A>,
+<A HREF="r.sun.html">r.sun</A>
+</em>
+
+<H2>AUTHOR</H2>
+
+E. Jorge Tizado (ej.tizado unileon es)<br>
+Dept. Biodiversity and Environmental Management, University of León, Spain
+
+<p>
+<i>Last changed: $Date$</i>
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