[GRASS-user] v.surf.rst vs r.slope.aspect

[Pierre Roudier]

Thanks Edgar, the results are indeed better with a bit of smoothing.

Cheers,

Pierre

2011/6/7 Edgar Pimiento <e_pimiento at yahoo.com>:
> Pierre,
>
> -r.param.scale is more appropriate for high resolution elevation data than other modules. It permits to select the kernel (window size) for the estimation of parameters. Land surface parameters depend on DEM resolution and size of computation window. High elevation data are susceptible to noise and it is better to use a kernel larger than 3 when calculating slope and other parameters.
>
> For references check module help and the following:  Wood, J.D. (1996) The geomorphological characterisation of digital elevation models PhD Thesis, University of Leicester, UK,http://www.soi.city.ac.uk/~jwo/phd; Hengl, T. and I. S. Evans (2009). Mathematical and Digital Models of the Land Surface. Geomorphometry- Concepts, Software, Applications. T. H. a. H. I. Reuter, Elsevier. Volume 33: 31-63; and Reuter, H. I., T. Hengl, et al. (2009). Preparation of DEMs for Geomorphometric Analysis. Geomorphometry- Concepts, Software, Applications. T. H. a. H. I. Reuter, Elsevier. Volume 33: 87-120.
>
>
> Edgar Pimiento
> e_pimiento at yahoo.com
> Public Works Division, Shimane Prefecture, Japan
>
> ________________________________
> From: Pierre Roudier <pierre.roudier at gmail.com>
> To: GRASS <grass-user at lists.osgeo.org>
> Sent: Tuesday, June 7, 2011 2:23 PM
> Subject: [GRASS-user] v.surf.rst vs r.slope.aspect
>
> Dear list,
>
> For a project, I need to derive parameters like slope and aspect from
> a high-res DEM from a LiDAR point cloud.
>
> There are several way to do this in GRASS:
>
> - v.surf.rst
> - r.slope.aspect
> - r.param.scale is a bit special and, I think, has a different purpose.
>
> How do RST and r.slope.aspect compare? I can see (using difference
> maps or the profile tool) the results are different, but I'm not too
> sure which one to use at the end of the day.
>
> Any thoughts/references on that?
>
> Cheers,
>
> Pierre
>
> --
> Scientist
> Landcare Research, New Zealand
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-- 
Scientist
Landcare Research, New Zealand