Geografic-Information-System/scripts/i.tasscap/i.tasscap.html

<H2>DESCRIPTION</H2>

<EM>i.tasscap</EM> calculates Tasseled Cap (Kauth Thomas, TC) transformation
for LANDSAT-TM data (TM4, TM5, TM7).

<!-- ok, but what is Tasseled Cap ? -->

The following TC components are generated:

<ul>
<li> tasscap.1: corresponds to brightness,
<li> tasscap.2: corresponds to greenness,
<li> tasscap.3: corresponds to wetness,
<li> tasscap.4: corresponds to atmospheric haze.
</ul>


<H2>EXAMPLE</H2>

Calculation of TC maps from North Carolina Landsat scene:

<div class="code"><pre>
g.region rast=lsat7_2002_10 -p
i.tasscap -7 band1=lsat7_2002_10 band2=lsat7_2002_20 \
             band3=lsat7_2002_30 band4=lsat7_2002_40 \
             band5=lsat7_2002_50 band7=lsat7_2002_70 \
	     outprefix=tasscap
</pre></div>

Results:

<p>
<center>
  <table border=1>
  <tr>
    <td align=center>
      &nbsp;<img src="tasscap1.jpg" alt="'Brightness' Tasseled Cap component 1">
      <br>
      <font size="-1">
      <i>'Brightness' Tasseled Cap component 1</i>
      </font>
    </td>
    <td align=center>
      &nbsp;<img src="tasscap2.jpg" alt="'Greenness' Tasseled Cap component 2">
      <br>
      <font size="-1">
      <i>'Greenness' Tasseled Cap component 2</i>
      </font>
    </td>
  </tr>
  <tr>
    <td align=center>
      &nbsp;<img src="tasscap3.jpg" alt="'Wetness' Tasseled Cap component 3">
      <br>
      <font size="-1">
      <i>'Wetness' Tasseled Cap component 3</i>
      </font>
    </td>
    <td align=center>
      &nbsp;<img src="tasscap4.jpg" alt="'Atmospheric haze' Tasseled Cap component 4">
      <br>
      <font size="-1">
      <i>'Atmospheric haze' Tasseled Cap component 4</i>
      </font>
    </td>
  </tr>
  </table>
</center>
<br>


<H2>REFERENCES</H2>

<ul>
<li>LANDSAT-4/LANDSAT-5: TC-factor changed to CRIST et al. 1986,
                      Proc. IGARSS 1986, p.1467
<li>LANDSAT-7: TASSCAP factors cited from:
  DERIVATION OF A TASSELED CAP TRANSFORMATION BASED ON LANDSAT 7 AT-SATELLITE REFLECTANCE
  Chengquan Huang, Bruce Wylie, Limin Yang, Collin Homer and Gregory Zylstra Raytheon ITSS, 
  USGS EROS Data Center Sioux Falls, SD 57198, USA
  http://landcover.usgs.gov/pdf/tasseled.pdf
<br>
 This is published as well in INT. J. OF RS, 2002, VOL 23, NO. 8, 1741-1748.
<br>
 Compare discussion:
 http://adis.cesnet.cz/cgi-bin/lwgate/IMAGRS-L/archives/imagrs-l.log0211/date/article-14.html
</ul>


<H2>AUTHOR</H2>

Markus Neteler, ITC-irst
<p>
<i>Last changed: $Date$</i>