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<div class="moz-cite-prefix"><font face="Times New Roman, Times,
serif">On 01/21/2013 08:21 PM, Hermann Peifer wrote:<br>
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<blockquote cite="mid:50FD953A.9020000@gmx.eu" type="cite"><font
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I just successfully tested your procedure using the 31 test
points given in BETA2007testdaten.csv [1].
And indeed: it is somewhat puzzling that one has to do step 8. I
"solved" the issue by defining the grid's Y extents as:
gdal_grid (...) -tye ymax ymin # rather than providing the
values in the documented order: -tye ymin ymax. Wild guess: This
looks to me like a bug in gdal_grid.cpp, perhaps around line
1000.
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Hermann
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[1]
<a class="moz-txt-link-freetext" href="http://crs.bkg.bund.de/crseu/crs/descrtrans/BeTA/BETA2007testdaten.csv">http://crs.bkg.bund.de/crseu/crs/descrtrans/BeTA/BETA2007testdaten.csv</a>
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<font face="Times New Roman, Times, serif">Good to hear!<br>
<br>
It would be interesting to compare the grid you produced with the
official BETA2007 grid. From what I know, those grids are made
from a few real measurements, that are interpolated to a grid. Of
course there are many interpolation methods. The default one for
gdal_grid is inverse distance squared, but more advanced
geostatistical methods (kriging?) could be more appropriate for
these data. As we are talking about accuracies in the centimeter
domain, the choice of method could be important. With these gdal
procedures, testing them has become really simple.<br>
<br>
Jan</font> <br>
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