[GRASS5] [bug #1060] (grass) precision problem in i.points/image library

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this bug's URL: http://intevation.de/rt/webrt?serial_num=1060
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Subject: precision problem in i.points/image library

grass binary for platform: Compiled from Sources

GRASS and NOAA AVHRR data

It seems that we have a precision problem in i.points resp.
the underlying transformation library.  NOAA/AVHRR data, imported
with latest GDAL/r.in.gdal contain thousand of ground control
points (GCPs), ordered row-wise.

The snapshot of i.points shows that there is a regular dis-location
of points in the target location while correct in source location.
This introduces an error which is not desired.

The example: ipoints_noaa.gif (88kb)
http://mpa.itc.it/markus/noaa/
shows in the left part the raw AVHRR in XY location, in the right
part the GCPs in Lat/Long. The lower right window shows that
the GCPs are no longer in a curve, but show a regular offset.

Help is desired to solve this problem.

Markus

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