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Up until now for reprojection of my WGS84 vector (.shp) and raster files (.tif), I have been using EPSG projections based on vector/raster central point's UTM zone.

But what happens if the envelope-area of the vector or raster file spans through two UTM zones? Here is an example of a raster spanning through UTM zones 40 and 41:

enter image description here

In that case is it even possible to use some EPSG projection or not? Should one of the two UTM zones be picked?

Hugo Roussaffa
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marco
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1 Answers1

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before to create your own projection system, you might find one which fit your region of interest . But never "combine" different maps created in differents UTM zones into one map with the expectation of great precision.

from this source

If we need to combine objects from several different UTM zones, the correct solution is to choose a different projection (such as a conic or azimuthal projection) for the combined map that provides low distortion over the entire region of interest

[...]

UTM was designed to map objects within one zone at a time. It is a very bad choice if objects from several zones must be shown together on the same map.

Hugo Roussaffa
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  • Thank you for the useful reply Hugo! I didn't intend to combine data from different UTM zones, but this is still very useful information! – marco Oct 28 '17 at 17:51