I've encountered a strange anomoly that's left me baffled. Etiher that, or I'm missing something quite badly... Anyway, I was wondering if anyone has encountered a similair scenario.
I've got set of shape files (Polygons) with the coordinate system LL-WGS84, and in my workspace, I use the reprojector to convert them to AFRICA-LM-CONIC. I then use the AreaCalculator transformer to generate the Square Km measurements for them.
However, for those of you who are familiar with ArcMap, if I do it there via reprojection and calculating geometry, my results are out, by a small amount.
I've triple check all my input and output projection settings in both FME and Arc, but no matter what, my measurements don't match up. For example.
VALLEYS.shp
Arc gets - 251936.47 Km²
Fme gets - 260142.65 Km²
About a 3.15% difference. Enough to create issues for what I'm trying to do.
And I just want to make it absolutely clear, that in both application, I convert the exact same data to the exact same coordinate system. So I'm left scratching my head as to whitch one is correct, and which one has some kind of issue.
Thanks in advance for any kind of help.