About r.surf.fractal

[Venkatesh Raghavan]

Hi Terry,
Your research sounds very interesting. Are you developing your application
on GRASS? Is there any published literature about you work?
I am very interested in your work. Bascically, we are trying to characterize
large scale landslides using fractal dimensions of their surfaces.
More info on your work would be a great help.

Thanks
Raghavan


Terry Duell wrote:

> Venkatesh Raghavan wrote:
> >
> > Hi,
> > Jacques Bouchard wrote:
> >
> > > BTW, what is the use of r.surf.fractal ?
> > >
> > I am developing a program to calculate fractal dimension of topographic
> > surfaces using DEM. I hope to check if is working okay using the
> > synthetic fractal surfaces generated by r.surf.fractal.
> >
> ---------snip-----------
> We have been working on an application to calculate the fractal dimensions of
> a surface (further development of an approach developed by Lawrence Martin at
> the US Army materiel Systems Analysis Activity).
> If the fractal dimension of a surface is known, one can use it to interpolate
> within a low resolution data set to generate a surface with higher resolution
> and appropriate properties (which one doesn't get by linear interpolation).
> This can be much more time and $ cost effective (for some purposes) than
> developing a 'true' higher resolution DEM.
> The approach adopted to establish the fractal dimension is based on the
> surface area to plan area of each 'cell' in a regular raster array, and
> calculating this for a number of resolutions of the sample data (ie at
> original resolution, then discard every second point etc).
> Tests thus far have promising results in fractal interpolation of DEM, but it
> must be added that quite a bit more testing is required.
> The theoretical aspects can be overshadowed by a poor choice of boundaries on
> the sample data (ie the sample data really contains a number of different
> 'roughness' surfaces which should be treated separately and not ascribed the
> same fractal number).
> Cheers,
> --
> Terry Duell, Senior Mobility Engineer
> Army Technology & Engineering Agency
> Maribyrnong, Victoria, Australia
> ph:61-3-93195837 fax:61-3-93195830