[GRASS-user] Peak point extraction from DEM

[Amagine]

Thanks Martin, I'll have a look at terrain analysis in grass.  See  
what I can come up with.

>> I would like to be able to regulate the following parameters:
>>
>> Minimum height of peak
>
> A topographic "peak" will have an elevation, not a range of  
> elevations. So
> I'm not sure what you mean.

I should have elaborated further.

Minimum height of peak, meaning do not classify any peaks below a set  
minimum threshold : 1000 m for instance.


>> Minimum drop of surrounding peaks
>
> Not sure what you mean here too.

Meaning a peak is not extracted if there are surrounding elevations  
within a minimum drop amount
eg. 50m or 100m (depending on accuracy of DEM file and refinement  
desired of distinct peaks)


>> summit points
>> optional hierarchy...
>>
>
> I guess these are technical mountaineering terms? So again I'm not  
> sure what
> data you are hoping to extract.

Summit points.... The highest point on a peak.

So a peak encompasses all vertical surface areas within the "Summit"  
point based on the above two categories.

I suppose I define a peak as a categorical area, and a summit as a  
point. Perhaps there are better definitions.

Hierarchy in my mind would be to classify peaks within peaks. Based  
on the initial two parameters (Minimum height of peak, minimum drop  
of surrounding peaks)

I suppose I should draw a picture :) probably make more sense.

Thanks!

Mars

On 1-Jul-07, at 10:03 PM, Michael Barton wrote:

>
>
>
> On 7/1/07 5:46 PM, "Amagine" <amagine at telus.net> wrote:
>
>> Hello, I am trying to extract peak points from a digital elevation  
>> map.
>
> (GUI menu: raster>terrain analysis>terrain parameters)
>
> r.param.scale input=DEM output=feature.map param=feature
>
> This will ID peaks, ridges, passes, channels, pits, and planes
>
> __________________________________________
> Michael Barton, Professor of Anthropology
> Director of Graduate Studies
> School of Human Evolution & Social Change
> Center for Social Dynamics & Complexity
> Arizona State University
>
> phone: 480-965-6213
> fax: 480-965-7671
> www: http://www.public.asu.edu/~cmbarton
>
>