Development of elevation maps

[S. E. Walker]

	We are trying to create an elevation raster map from
a paper contour map.  The original map is in feet; we want the
final product in meters.  I would think that the following
procedure would work:

	1) Digitize paper map using v.digit and label contours
            in feet.
	2) Convert the digitized map to a rasterized contour map.
	3) Run r.surf.contour to fill in the rasters between contours.
	4) Use r.mapcalc to convert from feet to meters.

	At step #3, however, we are getting a map that is "filled in"
but not interpolated; i.e. there is a green band for elevation 672, a light
blue band for elevation 674, etc., but nowhere is there an interpolated 
673, for example.  Is there a better way?  What's the difference between
r.surf.contour and r.surf.idw?  Is there anything to be gained by converting
the rasterized contour map to a sites file?  If so, how does one do this --
I don't see an 'r.to.sites' or something similar in the manual.

	Thanks for any advice.


Sharyl Walker
University of Illinois
guernsey at holstein.age.uiuc.edu