[GRASS5] Re: r.in.gdal - precision problem in lib/gis/adj_cellhd.c
neteler at itc.it
Thu Apr 7 11:09:36 EDT 2005
On Thu, Apr 07, 2005 at 04:25:38PM +1200, Hamish wrote:
> > Hacking lib/gis/adj_cellhd.c to permit the import,
> > I get the following cell header:
> > grassdata/latlong/PERMANENT/cellhd/srtm90_gtopo30
> > proj: 3
> > zone: 0
> > north: 90:00:00.000001N
> > south: 39:59:59.990613N
> > east: 20:00:00.007509E
> > west: 20:00:00.000001W
> > cols: 4800
> > rows: 6000
> > e-w resol: 0:00:30.000002
> > n-s resol: 0:00:30.000002
> > format: -1
> > compressed: 2
> > Probably it's a GRASS/GDAL issue with LatLong data?
> > Fixing the cell header files manually solved the
> > problem but isn't very elegant.
> > Any hints are welcome
> It's not trying to add half the cell to the top row of the TIFF, thus
> going beyond 90d 0' 15"?
Probably. But then we would exclude a lot of global data!
> I thought SRTM only made it to 60 deg lat anyway? Space Shuttle is not
> polar orbiting.
Note that these data are the GTOPO30 data enhanced by SRTM, not
the original SRTM data. So north of 60 deg GTOPO30 remained untouched AFAIK
> I have noticed in the past that v.out.ogr to a shapefile does similar
> strange off-by 1e-9 type errors to double precision columns in the
Mhh, a systematic problem?
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