[GRASS-user] Exporting GRASS contours to AutoCAD Map3D?

Hi,

I am fairly new into GIS, have had DeLorme Xmap for a while but am moving up…

I am looking for property in the countryside, and find the typical 20 or 30’ resolution of contour lines that seem to be the default from USGS or whomever supplies them to be not good enough. I would love to be able to buy better contour resolution. But I am guessing one cannot that easily.

The other way, when we are getting very serious about a property and planning house locations etc, would be to get a GPS data logger, strap it to the top of a remote control toy truck, and do a survey. I am sure that somehow I can figure out how to get GRASS to import the data and create much better contours. But would I then be able to export it to AutoCAD 2010 Map3D? Not sure if that is done/doable.

Any pointers would be most welcome; thanks in advance.tle

CrimsonApostle

Hi,

Some time ago I have imported elevation contour lines into Autocad
from GRASS using the module "v.out.dxf" which generates a DXF file
(readable by Autocad). It worked quite well except that I had to add
the elevation value as a contour line parameter in the DXF file. You
need this if you want to get the z-Value (elevation) when clicking on
a contour line in an Autocad worksheet. For this feature a break up
the source code of v.out.dxf but it was no big deal.

The other way, when we are getting very serious about a property and
planning house locations etc, would be to get a GPS data logger, strap it to
the top of a remote control toy truck, and do a survey.

That's a cool idea using a R/C truck but is the relative/absolute
accuracy sufficient for your needs? Do you want to use GPS or
differential GPS? For high resolution digital elevation models (1-3 m
horiz. res.) you can use stereo satellite images Quickbird/IKONOS or
even stereo oblique photographs? But this maybe also a question of
money :-).

Cheers,
Florian

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Florian Mueller
Remote Sensing, Snow & Ice, Meteorology, IT

Innsbruck, Austria
ICQ: 455740874
Skype: icephase26