[GRASSLIST:2615] Re: Moire effect in aspect map - solved

[Markus Neteler]

On Fri, Feb 13, 2004 at 06:28:05PM -0700, Christof Bigler wrote:
> Hamish pointed me to the fact that the pattern could be an artifact, 
> which might had been created when the original data had been processed. 
> And yes, indeed, when we were zooming into the aspect map in ArcGIS, we 
> could detect the same pattern. Thanks to Hamish and the others who 
> helped me!
> But I also have to consider that without this pattern, I wouldn't have 
> detected the inconsistency beetween gdal and grass, i.e. the missing 
> column and row when importing the map with r.in.gdal (see my former 
> e-mails).
> 
Christof,

please file a bugreport for this containing all relevant info.
http://grass.itc.it/bugtracking/bugreport.html

Markus

> 
> On 12.02.2004, at 18:53, Hamish wrote:
> 
> >>The second and original problem with the moire effect in the aspect 
> >>map
> >>also remains, even 1) when I derive aspect from the newly imported
> >>*.e00 raster map, or 2) when I import the aspect map from a *.e00 
> >>file,
> >>which has been derived in ArcGIS, or 3) when I export the map as TIFF.
> >>BUT, there is no such effect, when I look e.g. at the map 'aspect' 
> >>from
> >>the spearfish data set, which has exactly the same resolution as the
> >>default settings.
> >>
> >>Any comments on this issue?
> >
> >It could be an artifcat of the original data set & processing.
> >
> >?
> >Hamish

-- 
Markus Neteler     <neteler itc it>       http://mpa.itc.it
ITC-irst -  Centro per la Ricerca Scientifica e Tecnologica
MPBA - Predictive Models for Biol. & Environ. Data Analysis
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