[Qgis-user] cross section from raster-data

[Alister Hood]

Hi Lars,

> Date: Fri, 16 Sep 2011 07:45:54 +0200
> From: Lars Schw?tzer <lsc at ruhrverband.de>
> Subject: [Qgis-user] cross section from raster-data
> To: qgis-user at lists.osgeo.org
> Message-ID: <4E72E292.5050201 at ruhrverband.de>
> Content-Type: text/plain; charset=ISO-8859-15; format=flowed
> 
> Hi List,
> 
> I want to calculate a cross section along a line from a raster-data.
In
> the best way I get a Chart [Coords from the line] / [value of raster].
> Is there a way to do this automaticly with Qgis?
> 
> Regards,
> Lars

There are several options:
1) The "profile" plugin allows you to draw a straight line on the map
and plots the profile of up to three one-band rasters.  The raster CRS
must be the same as the project CRS (unless on-the-fly projection is
disabled).

2) The "profile from line" plugin generates a layer of points spread
along the lines (or just the selected lines) in a polyline layer.  At
each point it samples any number of one-band rasters and stores the
values as attributes.  I think this plugin requires the raster and
vector layers to be in the same projection as each other, and it doesn't
work with memory layers.

3) The "profile export" plugin samples the first segment of a selected
polyline feature, storing the values in an xml file formatted for some
German cable car design software.  It requires the line and raster
layers to be in the same CRS.

While we're discussing cross/long section plugins, I seem to remember a
plugin which put any intersecting vector features (from any layer) on a
section.  I can't find anything like that now - does anybody know of
something which does this, or did I imagine it?


Alister