Take the 2-minute tour ×
Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. It's 100% free, no registration required.

I am looking to perform a simple (one observer location) viewshed analysis on a standard DEM using GDAL (either python or .NET bindings).

I have searched, but haven't found any readily available implementation. Can anyone point me in the right direction?

share
    
Is GRASS an acceptable candidate for your solution? It typically includes tools for these things: r.los and r.viewshed –  Peter Smith Jul 12 '12 at 21:45

3 Answers 3

up vote 4 down vote accepted

I've used python scripts to run both the r.los and r.viewshed grass commands that Peter mentioned.

The advantage with r.los is that it works straight out-of-the-box with grass6, but is slightly slower to run over large raster DEMs. r.viewshed is a bit of a pain to get running, but is a vast speed improvement on very large rasters. See if the times for your DEM are acceptable using r.los, then give r.viewshed a go if it's taking too long. Here's a quick python example using grass64 r.viewshed, but you'll need to get the python grass bindings working first (see http://grass.osgeo.org/wiki/GRASS_and_Python).

import grass.script as grass

grass.run_command('r.viewshed',
        input='standard.dem',
        output='viewshed',
        coordinate=[observer_x, observer_y],
        obs_elev=1.75,
        tgt_elev=0.0,
        memory=4098,
        overwrite=True,
        quiet=True
)

with a better description of the parameters available at http://grass.osgeo.org/gdp/html_grass70/r.viewshed.html

share

There is also SAGA-GIS which provides visibility analysis. It has Python bindings.

share

There is also a QGIS plugin that does this. I can not remember the name of the plugin at the moment, it works, but I find it a little slow.

share
    
It's been a while since you sort of answered this question without a real answer? Do you have an update or maybe just delete the answer? –  RyanDalton Dec 5 '12 at 6:54
    
Thank you for the reminder Ryan, and sorry for forgetting. Here is a link to a description about the plugin. I did a search for the plugin in for QGIS 1.8.0 and it is not coming up in the Plugin Search. madchuckle.blogspot.ca/2010/05/… –  Ryan Garnett Dec 5 '12 at 19:56
    
Here is another description of the plugin madchuckle.blogspot.ca/2010/10/… –  Ryan Garnett Dec 5 '12 at 19:56

This site is currently not accepting new answers.

Not the answer you're looking for? Browse other questions tagged .