i.rectify2

[H. Olthof]

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response to:

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I do not understand the problems claimed for accuracy.  Lcc is
a closed form computation and thus is hardware precision limited while
TM (and UTM) is inherently less accruate because it is based upon
truncated approximation series (but still good to mm).

Please specify the details as to your accuracy claims.  What are you
comparing to?  Do you have a set of coodinates that you could send
that illustrate your problem?

Gerald (Jerry) I. Evenden   Internet: gie at charon.er.usgs.gov
voice: (508)563-6766          Postal: P.O. Box 1027
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I have both vector data and rasterdata in my lat-lon mapset. I made the coordinate transformation from ll-->lcc for the vector data with v.proj.
For the raster data I used i.rectify2 as described.
Now, if you make an overlay in the lcc mapset. (the vector map over the raster data) they don't
fit. They are shifted up to tens of kilometers. in some of the Greek islands, the 'vector island' and the `raster island` don't even overlap!
In order to check my results I have transformed a vector map (with v.proj) and a raster map which was derived from this vector map (In the lat-lon mapset, using v.to.rast)
I would expect that both maps would fit exact in the lcc mapset, as they did in the lat-lon mapset. But no....
So either v.proj is not accurate (but since this is a coordinate transformation for which the transformation formulas are known, I have assumed that my vector data are correct) 
Or,
i.rectify2 is not accurate enough. (which I can understand, because the area is large and i.rectify only makes a fit, for the transformation matrix).
Or, 
I am missing something and there is an other solution for this problem.