Raster to Vector
Terry Duell
duell at atea.mat.army.defence.gov.au
Mon Oct 12 01:33:29 EDT 1998
Akihiko Machida wrote:
>
> Dear Sir/Madam,
>
> We want to create contour map of 1m from 250m mesh raster map.
> Does anyone have a creative solution?
>
> Our objective is to simulate the area of inundation from 1m rise of
> sea level.$B!!(J We have a limitation data and somehow we must infer the(J
> elevation of 1m range.
> $B!!(
I think that you may have some trouble getting a result that makes nay sense
if your elevation data is at 250m spacing. That grid was probably built from
quite sparse data which may have had a vertical accuracy of 50m or more.
I would be trying to get the original spot height data that was used to build
the 250m raster, and exporting that to another application such as MIPS, and
then building a TIN and extracting a fine reolution grid from that. This way
at least you will be able to interpolate better between known points in the
original data, and the finer the grid the smaller the error in flooded area.
The large 250 grid data can lead to large errors in coverage for each m rise
in water level.
Hope this helps.
--
Terry Duell
More information about the grass-user
mailing list