Geografic-Information-System/scripts/r.in.wms/r.in.wms.html

<H2>DESCRIPTION</H2>

<EM>r.in.wms</EM>  handles all of downloading and importing raster data from
an <a href="http://www.opengeospatial.org/specs/?page=specs">OpenGIS</a>
"WMS" web mapping server. It need only be told the desired data to collect
(bounds and resolution) via a region, the server to get the data from, and
the layer or layers to get. It downloads the data in tiles, reprojects it,
imports it, and patches it back together.

<H2>NOTES</H2>

By default data is downloaded to $GISDBASE/wms_download. This can be changed
by setting the <EM>folder=</EM> option when using <EM>r.in.wms</EM>.
<P>
To understand the data you are getting it is necessary to look at the
capabilities of the WMS server. This should be available via a capabilities
request. This is an
<a href="http://wms.jpl.nasa.gov/wms.cgi?request=GetCapabilities">example
capabilities request to NASA's OnEarth server</a>.
<P>
Some brain-dead servers will only talk to certain web browsers. You can
fool these by adding "<tt>--user-agent=MSIE5.5</tt>" to <b>wgetoptions</b>
or for curl adding "<tt>-A "MSIE5.5</tt>" to <b>curloptions</b>.
Other brain-dead servers will not accept queries in the form of POST data.
If you get an error try using the <b>-g</b> flag to force <em>r.in.wms</em>
to send an atomic GET request instead.


<H2>EXAMPLES</H2>

<H3>General Get Capabilities Request</H3>

A capabilities request like
<a href="http://wms.jpl.nasa.gov/wms.cgi?request=GetCapabilities">http://wms.jpl.nasa.gov/wms.cgi?request=GetCapabilities</a>
is where you should start. It tells you what data is offered, the projections
it is in,  where to find meta data, resolutions, scales, and bounds for
data, etc.

<H3>NASA OnEarth server: Get Capabilities Request</H3>

<div class="code"><pre>
r.in.wms mapserver=http://wms.jpl.nasa.gov/wms.cgi -l
</pre></div>

Lists the layers available from the NASA OnEarth server. The output is
more reliable if <a href="http://ofb.net/~egnor/xml2/">xml2</a> is installed.


<H3>US NED Elevation from OnEarth server download (metric units)</H3>

Set the resolution to 30 (assuming you're in metric units):
<div class="code"><pre>
g.region res=30 -ap
r.in.wms output=elevation_meters mapserver=http://wms.jpl.nasa.gov/wms.cgi \
         layers=us_ned styles=real -o
</pre></div>

Downloads real number meter elevation from OnEarth to cover the current
region. Uses -o for opaque to get smaller download.

<H3>US NED Elevation from OnEarth server download (feet units)</H3>

Set the resolution to 90 (assuming you're in feet units) a save this
region with a name; this makes resuming downloads possible or rather
easier:

<div class="code"><pre>
g.region res=90 -ap
g.region save=panhandle-90ft

r.in.wms output=elevation_feet mapserver=http://wms.jpl.nasa.gov/wms.cgi \
         layers=us_ned styles=feet_real -o region=panhandle-90ft
</pre></div>

Downloads real number feet elevation from OnEarth to cover the current
region. Uses <B>-o</B> for opaque to get smaller download. Using a named
region lets us resume later easily.

<div class="code"><pre>
r.in.wms output=elevation_feet mapserver=http://wms.jpl.nasa.gov/wms.cgi \
         layers=us_ned styles=feet_real -o region=panhandle-90ft -d method=cubic
</pre></div>

<b>-d</b> skips ahead to downloading. This could be used to try
downloading again (if some files failed last time) or to import the data
differently. Since downloaded files are remembered those already received
successfully are not re-requested. In this case we are reimporting the
data using the cubic interpolation method instead of nearest neighbor.

<H3>LANDSAT from OnEarth server download</H3>

Set the resolution to 30 meters for LANDSAT:
<div class="code"><pre>
g.region res=30 -ap
r.in.wms layers=global_mosaic mapserver=http://wms.jpl.nasa.gov/wms.cgi \
         output=wms_global_mosaic
</pre></div>
Downloads LANDSAT color scene.


<H3>DRG from Terraserver server download</H3>

Set the resolution to 1.2 meters for DRGs. Their native resolution is
2.4 meters, so this is some pretty hefty oversampling:

<div class="code"><pre>
g.region res=1.2 -ap
g.region save=drg-resolution

r.in.wms output=terraserver-drg mapserver=http://terraserver.microsoft.com/ogcmap6.ashx \
         layers=DRG region=drg-resolution format=jpeg srs=EPSG:26910
</pre></div>

Downloads digital raster graphics from Microsoft TerraServer. Note that
srs will need to be changed to a projection that is appropriate for your
region.


<H2>REQUIRED PROGRAMS</H2>

<EM>r.in.wms</EM> requires the following programs to work:

<ul>
<li>wget: An http download program, or
<li>curl: Alternate http download program
<li>bc: A calculator program
<li>sed, grep: Unix string processing and search programs
<li><a href="http://www.gdal.org">gdalwarp</a>: A reprojection tool,
    needed only if data is projected into this location.
<li><a href="http://ofb.net/~egnor/xml2/">xml2</a>: An xml parser.
    Enables more accurate listing of layers on the server.
</ul>


<H2>SEE ALSO</H2>
<a href="r.tileset.html">r.tileset</a>,
<a href="r.in.gdal.html">r.in.gdal</a>,
<a href="r.patch.html">r.patch</a>


<H2>AUTHORS</H2>

Soeren Gebbert, Jachym Cepicky, and Cedric Shock

<p>
<i>Last changed: $Date$</i>