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

[Moritz Lennert]

On 07/06/11 07:23, Pierre Roudier wrote:
> 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.

v.surf.rst estimates a surface from points and then gives you the slope 
and aspect resulting directly from the approximation function. 
r.slope.aspect uses an existing DEM and calculates slope and aspects 
within a 3x3 neighbourhood.

When you say that there are differences, which DEM did you use with 
r.slope.aspect ? The one create by the v.surf.rst run ?

Moritz