[GRASSLIST:3877] Re: s.surf.idw help

[Gordon Keith]

On Sat, 8 Jun 2002 01:09, Kevin Slover wrote:
> I am attempting to use r.surf.idw to create a finer resolution data
> set for GLOBE data.  Currently, I have imported the data at .001 deg
> X .001 deg res, and am trying to get to .0005 X .0005 deg res...it
> starts fine,

Kevin,

For what it's worth the procedure I'm using to get a reasonable 
resolution (10m) raster from random site data (raw multibeam acoustic 
bathymetry) is as follows:

g.region -p
projection: 3 (Latitude-Longitude)
zone:       0
datum:      wgs84
ellipsoid:  wgs84
north:      -37.8
south:      -37.83
west:       149.12
east:       149.18
nsres:      0.00009009
ewres:      0.00011429
rows:       333
cols:       525

s.in.ascii in=accept.xyz.ascii sites=pthicks_accept

s.to.rast input=pthicks_accept output=pthicks_accept

s.surf.rst input=pthicks_accept elev=pthicks_surf tension=10 zmult=-1 
maskmap=pthicks_accept

r.mapcalc 'pthicks_surf=if(pthicks_surf < -10, pthicks_surf, null())'

r.slope.aspect elev=pthicks_surf slope=pthicks_slope 
aspect=pthicks_aspect pcurv=pthicks_profile tcurv=pthicks_tangent

I don't claim any expertise, and I haven't played around with the 
tension parameter to really understand what it does, but since you seem 
to be tackling similar sorts of issues to me I thought I'd let you know 
what I'm doing.

Any comments or suggestions on improvement would always be appreciated.

Regards
Gordon

-- 

Gordon Keith
Programmer/Data Analyst
Marine Acoustics
CSIRO Marine Research
http://www.marine.csiro.au

"Computers are useless. They can only give you answers." 
- Pablo Picasso, 1968