Detect coordinate system UTM 32 North or UTM 33 North

Question

I am getting database tables (dbase) from customers with geo coordinates either in Gauss-Krueger (zone 2 to 5) and UTM 32 North or UTM33 North, usually from within Germany. Sometimes there is no explicit description which coordinate system is being used (and the customer sometimes doesn't even know it himself) so I would like to detect it.

Gauss-Krueger is easy because the easting value is prefixed with the meridian / zone, so I know that e.g. 4584282;5836214 is Gauss-Krueger Zone 4.

With UTM that's apparently not the case (no preceding zone number 32 / 33 in the data). Is there any way to automatically detect the zone? E.g. how do I know where 381208;5835042 is located? In this case I know for sure that it is zone 33, near Berlin, but in other cases that's not known. Any hints?

Answer 1

There is no way to tell, unless the area of interest doesn't share the same coordinates. For instance, with zone 32 North, the range of easting/X coordinates are >500000 while the range is <500000 for zone 33 North.

If the areas tend to be large, you can also look at the extents. For instance, if you get an extent that ranges in easting values from 400k to 600k, but you know the area of interest doesn't extend that far in 33 North, you can be relatively sure that it's zone 32 North.