geometry calculating in differnet coordinate systems results in different...

Discussion created by niktheking on Nov 6, 2013

Maybe I have a very simple question about geometry calculating.

First I have a shape with just ohne area in the coordinate system DHDN_GK4 (something German). If I calculate the area size it tells me, that the area has 9911 hectares. If I project this shape into DHDN_GK3 (which is the most "common" coordinate system in Germany) and calculate the areas size again, it tells me now, that thw size is 9934 hectares!
So - and just for fun - if I finally (re-)project into DHDN_GK4 and calculating the areas size again, it tells me NOT the 9911 hectares like it was at the beginning... It is still 9934 hectares like the result of culculating geometry in DHDN_GK3.

So where is my or ESRIs problem?