[GRASS-SVN] r68457 - in grass/branches/releasebranch_7_0/imagery: . i.albedo i.aster.toar i.atcorr i.biomass i.landsat.acca i.landsat.toar

svn_grass at osgeo.org svn_grass at osgeo.org
Wed May 18 00:11:09 PDT 2016

Author: neteler
Date: 2016-05-18 00:11:09 -0700 (Wed, 18 May 2016)
New Revision: 68457

i.atcorr manual, imageryintro: clarify TOAR part; cross links added; keywords added (trunk, r68456)

Modified: grass/branches/releasebranch_7_0/imagery/i.albedo/main.c
--- grass/branches/releasebranch_7_0/imagery/i.albedo/main.c	2016-05-18 07:07:29 UTC (rev 68456)
+++ grass/branches/releasebranch_7_0/imagery/i.albedo/main.c	2016-05-18 07:11:09 UTC (rev 68457)
@@ -88,6 +88,11 @@
+    G_add_keyword(_("satellite"));
+    G_add_keyword(_("Landsat"));
+    G_add_keyword(_("ASTER"));
+    G_add_keyword(_("AVHRR"));
+    G_add_keyword(_("MODIS"));
     module->description = _("Computes broad band albedo from surface reflectance.");
     /* Define the different options */

Modified: grass/branches/releasebranch_7_0/imagery/i.aster.toar/i.aster.toar.html
--- grass/branches/releasebranch_7_0/imagery/i.aster.toar/i.aster.toar.html	2016-05-18 07:07:29 UTC (rev 68456)
+++ grass/branches/releasebranch_7_0/imagery/i.aster.toar/i.aster.toar.html	2016-05-18 07:11:09 UTC (rev 68457)
@@ -1,9 +1,9 @@
 <em>i.aster.toar</em> calculates the Top Of Atmosphere (TOA) reflectance
-for Terra-Aster L1B in the visible, NIR and SWIR bands (9+1 bands) and
+for Terra-ASTER L1B in the visible, NIR and SWIR bands (9+1 bands) and
 brigthness temperature for the TIR bands (5 bands), all from L1B DN values. 
-It is useful after importing your Aster imagery from storage format that
+It is useful to apply after import of original ASTER imagery that
 is generally in standard DN values range.
@@ -35,8 +35,12 @@
 <a href="r.in.aster.html">r.in.aster</a>
+ASTER sensor data download:
+<a href="http://asterweb.jpl.nasa.gov/">ASTER: Advanced Spaceborne Thermal Emission and Reflection Radiometer</a>
 Yann Chemin, CSU, Australia
 <p><i>Last changed: $Date$</i>

Modified: grass/branches/releasebranch_7_0/imagery/i.aster.toar/main.c
--- grass/branches/releasebranch_7_0/imagery/i.aster.toar/main.c	2016-05-18 07:07:29 UTC (rev 68456)
+++ grass/branches/releasebranch_7_0/imagery/i.aster.toar/main.c	2016-05-18 07:11:09 UTC (rev 68457)
@@ -96,10 +96,11 @@
     module = G_define_module();
     G_add_keyword(_("radiometric conversion"));
-    G_add_keyword(_("Terra-ASTER"));
     G_add_keyword(_("brightness temperature"));
+    G_add_keyword(_("satellite"));
+    G_add_keyword(_("ASTER"));
     module->description =
 	_("Calculates Top of Atmosphere Radiance/Reflectance/Brightness Temperature from ASTER DN.\n");

Modified: grass/branches/releasebranch_7_0/imagery/i.atcorr/README
--- grass/branches/releasebranch_7_0/imagery/i.atcorr/README	2016-05-18 07:07:29 UTC (rev 68456)
+++ grass/branches/releasebranch_7_0/imagery/i.atcorr/README	2016-05-18 07:11:09 UTC (rev 68457)
@@ -38,7 +38,7 @@
   create_iwave.py <csv file>
-If generates the filter function as IWave.cpp template from csv file.
+It generates the filter function as an insert for IWave.cpp from the given file.
 Note: If the spectral response is null for a frequency, leave it empty
 in csv file. Ex.:

Modified: grass/branches/releasebranch_7_0/imagery/i.atcorr/i.atcorr.html
--- grass/branches/releasebranch_7_0/imagery/i.atcorr/i.atcorr.html	2016-05-18 07:07:29 UTC (rev 68456)
+++ grass/branches/releasebranch_7_0/imagery/i.atcorr/i.atcorr.html	2016-05-18 07:11:09 UTC (rev 68457)
@@ -617,9 +617,11 @@
 It is important to verify the available metadata for the sun position which
 has to be defined for the atmospheric correction. An option is to check the
-satellite overpass time with sun position as reported in
-<a href="ftp://ftp.glcf.umiacs.umd.edu/glcf/Landsat/WRS2/p016/r035/p016r035_7x20020524.ETM-EarthSat-Orthorectified/p016r035_7x20020524.met">metadata</a>. For the North Carolina sample dataset, they have also been
-stored for each channel and can be retrieved like this:
+satellite overpass time with sun position as reported in the
+<a href="ftp://ftp.glcf.umd.edu/glcf/Landsat/WRS2/p016/r035/p016r035_7x20020524.ETM-EarthSat-Orthorectified/p016r035_7x20020524.met">metadata</a>
+file (<a href="http://www.grassbook.org/wp-content/uploads/ncexternal/landsat/2002/p016r035_7x20020524.met">file copy</a>; North Carolina
+sample dataset). In case of the North Carolina sample dataset, values
+have been stored for each channel and can be retrieved like this:
 <div class="code"><pre>
 r.info lsat7_2002_40
@@ -636,13 +638,23 @@
 # .. reports: sun azimuth: 121.342461, sun angle above horz.(refraction corrected): 65.396652
-If the overpass time is unknown, use the <a href="http://www-air.larc.nasa.gov/tools/predict.htm">Satellite Overpass Predictor</a>.
-<p>Convert DN (digital number = pixel values) to Radiance at top-of-atmosphere (TOA), using the
+If the overpass time is unknown, use the
+<a href="http://cloudsgate2.larc.nasa.gov/cgi-bin/predict/predict.cgi">NASA LaRC Satellite Overpass Predictor</a>.
+<h4>Conversion of digital number (DN) to radiance at top-of-atmosphere (TOA)</h4>
+For Landsat and ASTER, the conversion can be conveniently done with
+<a href="i.landsat.toar.html">i.landsat.toar</a> or <a href="i.aster.toar.html">i.aster.toar</a>,
+In case of different satellites, the conversion of DN (digital number = pixel values) to
+radiance at top-of-atmosphere (TOA) can also be done manually, using e.g. the formula
 <div class="code"><pre>
+# formula depends on satellite sensor, see respective metadata
 <li> Lλ = Spectral Radiance at the sensor's aperture in Watt/(meter squared * ster * µm), the
       apparent radiance as seen by the satellite sensor;</li>
@@ -653,9 +665,10 @@
 <li> QCALMAX = the maximum quantized calibrated pixel value (corresponding to LMAXλ) in DN=255.</li>
-LMINλ and LMAXλ are the radiances related to the minimal and maximal DN value, and are reported
-in the metadata file for each image, or in the table 1. High gain or low gain is also reported
-in the metadata file of each Landsat image. The minimal DN value (QCALMIN) is 1 for Landsat ETM+
+LMINλ and LMAXλ are the radiances related to the minimal and
+maximal DN value, and are reported in the metadata file for each image, or in
+the table 1. High gain or low gain is also reported in the metadata file of each
+satellite image. For Landsat, the minimal DN value (QCALMIN) is 1 for Landsat ETM+
 images (see
 <a href="http://landsathandbook.gsfc.nasa.gov/pdfs/Landsat7_Handbook.pdf">Landsat handbook</a>, see chapter 11),
 and the maximal DN value (QCALMAX) is 255. QCAL is the DN value for every
@@ -677,7 +690,16 @@
 r.mapcalc "lsat7_2002_40_rad = ((241.1 - (-5.1)) / (255.0 - 1.0)) * (lsat7_2002_40 - 1.0) + (-5.1)"
+Again, the <em>r.mapcalc</em> calculation is only needed when working with satellite data
+other than Landsat or ASTER.
+<h4>Creation of parameter file for i.atcorr</h4>
+The underlying 6S model is parametrized through a control file, indicated with the
+<em>parameter</em> option. This is a text file defining geometrical and atmospherical
+conditions of the satellite overpass. Below some details:
 <div class="code"><pre>
 # find mean elevation (target above sea level, used as initialization value in control file)
 r.univar elevation
@@ -719,7 +741,10 @@
 GRASS Wiki page about
   <a href="http://grasswiki.osgeo.org/wiki/Atmospheric_correction">Atmospheric correction</a>
+<a href="i.aster.toar.html">i.aster.toar</a>,
+<a href="i.landsat.toar.html">i.landsat.toar</a>,
 <a href="r.info.html">r.info</a>,
 <a href="r.mapcalc.html">r.mapcalc</a>,
 <a href="r.univar.html">r.univar</a>

Modified: grass/branches/releasebranch_7_0/imagery/i.atcorr/main.cpp
--- grass/branches/releasebranch_7_0/imagery/i.atcorr/main.cpp	2016-05-18 07:07:29 UTC (rev 68456)
+++ grass/branches/releasebranch_7_0/imagery/i.atcorr/main.cpp	2016-05-18 07:11:09 UTC (rev 68457)
@@ -433,6 +433,10 @@
 	_("6S - Second Simulation of Satellite Signal in the Solar Spectrum.");
     G_add_keyword(_("atmospheric correction"));
+    G_add_keyword(_("radiometric conversion"));
+    G_add_keyword(_("radiance"));
+    G_add_keyword(_("reflectance"));
+    G_add_keyword(_("satellite"));
        " Incorporated into Grass by Christo A. Zietsman, January 2003.\n"

Modified: grass/branches/releasebranch_7_0/imagery/i.biomass/i.biomass.html
--- grass/branches/releasebranch_7_0/imagery/i.biomass/i.biomass.html	2016-05-18 07:07:29 UTC (rev 68456)
+++ grass/branches/releasebranch_7_0/imagery/i.biomass/i.biomass.html	2016-05-18 07:11:09 UTC (rev 68457)
@@ -8,14 +8,17 @@
  <li>Light Use Efficiency [0.0-1.0], in Uzbekistan cotton is at 1.9 most of the time.
  <li>Latitude [0.0-90.0], from <em>r.latlong</em>.
  <li>DOY [1-366].
- <li>Transmissivity of the Atmosphere single-way [0.0-1.0], mostly around 0.7+ in clear sky.
+ <li>Transmissivity of the atmosphere single-way [0.0-1.0], mostly around 0.7+ in clear sky.
  <li>Water availability [0.0-1.0], possibly using direct output from <em>i.eb.evapfr</em>.
-It can use the output of i.eb.evapfr directly as water availability input.
+<em>i.biomass</em> can use the output of <em>i.eb.evapfr</em> directly
+as water availability input.
 Remove Latitude, DOY and Tsw from input and replace with a raster 
 input compatible with <em>r.sun</em> output.
@@ -23,7 +26,8 @@
 <a href="i.eb.evapfr.html">i.eb.evapfr</a>,
-<a href="r.latlong.html">r.latlong</a>
+<a href="r.latlong.html">r.latlong</a>,
+<a href="r.sun.html">r.sun</a>
@@ -38,7 +42,7 @@
 sensing in transition economies. Water International. 30(4):513-521.
 Yann Chemin, Bec de Mortagne, France

Modified: grass/branches/releasebranch_7_0/imagery/i.landsat.acca/i.landsat.acca.html
--- grass/branches/releasebranch_7_0/imagery/i.landsat.acca/i.landsat.acca.html	2016-05-18 07:07:29 UTC (rev 68456)
+++ grass/branches/releasebranch_7_0/imagery/i.landsat.acca/i.landsat.acca.html	2016-05-18 07:11:09 UTC (rev 68457)
@@ -51,6 +51,7 @@
 <h2>SEE ALSO</h2>
+<a href="i.atcorr.html">i.atcorr</a>,
 <a href="i.landsat.toar.html">i.landsat.toar</a>

Modified: grass/branches/releasebranch_7_0/imagery/i.landsat.acca/main.c
--- grass/branches/releasebranch_7_0/imagery/i.landsat.acca/main.c	2016-05-18 07:07:29 UTC (rev 68456)
+++ grass/branches/releasebranch_7_0/imagery/i.landsat.acca/main.c	2016-05-18 07:11:09 UTC (rev 68457)
@@ -103,9 +103,10 @@
     module->description =
 	_("Performs Landsat TM/ETM+ Automatic Cloud Cover Assessment (ACCA).");
-    G_add_keyword(_("Landsat"));
     G_add_keyword(_("cloud detection"));
+    G_add_keyword(_("satellite"));
+    G_add_keyword(_("Landsat"));
     band_prefix = G_define_standard_option(G_OPT_R_BASENAME_INPUT);
     band_prefix->label = _("Base name of input raster bands");

Modified: grass/branches/releasebranch_7_0/imagery/i.landsat.toar/main.c
--- grass/branches/releasebranch_7_0/imagery/i.landsat.toar/main.c	2016-05-18 07:07:29 UTC (rev 68456)
+++ grass/branches/releasebranch_7_0/imagery/i.landsat.toar/main.c	2016-05-18 07:11:09 UTC (rev 68457)
@@ -72,8 +72,9 @@
     G_add_keyword(_("brightness temperature"));
+    G_add_keyword(_("atmospheric correction"));
+    G_add_keyword(_("satellite"));
-    G_add_keyword(_("atmospheric correction"));
     module->overwrite = TRUE;
     /* It defines the different parameters */

Modified: grass/branches/releasebranch_7_0/imagery/imageryintro.html
--- grass/branches/releasebranch_7_0/imagery/imageryintro.html	2016-05-18 07:07:29 UTC (rev 68456)
+++ grass/branches/releasebranch_7_0/imagery/imageryintro.html	2016-05-18 07:11:09 UTC (rev 68457)
@@ -20,8 +20,9 @@
 applying the reverse formula <tt>(x = (y - b) / a)</tt>.
 The GRASS GIS module <a href="i.landsat.toar.html">i.landsat.toar</a>
-easily transforms Landsat DN to radiance-at-sensor. The equivalent 
-module for ASTER data is <a href="i.aster.toar.html">i.aster.toar</a>.
+easily transforms Landsat DN to radiance-at-sensor (top of atmosphere,
+TOA). The equivalent module for ASTER data is
+<a href="i.aster.toar.html">i.aster.toar</a>.
 For other satellites, <a href="r.mapcalc.html">r.mapcalc</a> can 
 be employed.
@@ -30,11 +31,18 @@
 When radiance-at-sensor has been obtained, still the atmosphere 
 influences the signal as recorded at the sensor. This atmospheric 
 interaction with the sun energy reflected back into space by 
-ground/vegetation/soil needs to be corrected. There are two ways to 
-apply atmospheric correction for satellite imagery. The simple way 
-for Landsat is with <a href="i.landsat.toar.html">i.landsat.toar</a>,
+ground/vegetation/soil needs to be corrected. The need of
+removing atmospheric artifacts stems from the fact that the
+atmosphericic conditions are changing over time. Hence, to gain
+comparability between Earth surface images taken at different
+times, atmospheric need to be removed converting at-sensor values
+which are top of atmosphere to surface reflectance values.
+In GRASS GIS, there are two ways to apply atmospheric correction for
+satellite imagery. A simple, less accurate way for Landsat is with
+<a href="i.landsat.toar.html">i.landsat.toar</a>,
 using the DOS correction method. The more accurate way is using 
-<a href="i.atcorr.html">i.atcorr</a> (which works for many satellite 
+<a href="i.atcorr.html">i.atcorr</a> (which supports many satellite 
 sensors). The atmospherically corrected sensor data represent 
 surface <a href="http://en.wikipedia.org/wiki/reflectance">reflectance</a>,
 which ranges theoretically from 0% to 100%. Note that this level of 

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