[GRASSLIST:4238] GRASS 5.7.0 (2004) - v.surf.rst strange behaviour

[Javier A. Yebrin]

Hi all!

I'm trying to interpolate a laser-altimeter survey in order to fill null
areas. I've mainly followed by hand the procedure contained in the script
r.fillnulls .
The problem arises after the v.surf.rst module because the resulting
elevation map is at a very first glance not correct: it looks like a ramp,
the height values increasing linearly from North to South leading to absurd
values such as 300000 meters at the bottom part...
The lidar survey is a floating point map and it has been resampled to a
3mx3m grid.

These are the steps:

1. Creating and growing a MASK for the null values

r.mapcalc temp_raster="if(isnull(LIDAR))"
r.grow in=temp_raster out=MASK

2. Vectorize the raster file: here i get a warning. Should i care?

r.to.vect -v in=LIDAR out=temp_vector feature=point
WARNING: Raster is not CELL, '-v' flag ignored, raster values will be
written to the table.

Just to verify, a simple d.what.vect gives:

map: 'temp_vector'
mapset: 'javier'
feature type: Point
field: 1
category: 221891
driver: dbf
database: /grassdata/tovel_utm32/javier/dbf
table: temp_vector
key column: cat
cat :  221891
value :  1461.560059

3. Interpolate the points with RST

v.surf.rst in=temp_vector elev=interp_raster

4. View results. This is the history file for interp_raster(note zmin and
zmax)

Tue Aug 24 16:25:01 2004
interp_raster
javier
javier
raster
vector file temp_vector
generated by v.surf.rst
tension=40.000000, smoothing=0.100000
dnorm=96.007102, dmin=1.500000, zmult=1.000000
segmax=40, npmin=200, rmsdevi=1.734224
zmin_data=1.000000, zmax_data=324402.000000
zmin_int=-9.806899, zmax_int=324404.267325

Any ideas?
Thanks in advance

Javier Yebrin