Dear Sir/ Madam,
So I would like to reproject my CityGML model (ground surface) from EPSG 2326 to EPSG 3857.
However, I notice that the area is changed, even though they are both in meters.
May I ask if is it normal? Is there any reason behind this?
Thank you very much.
With regards,
Zach
EPSG 2326 is a Transverse Mercator, 3857 is a regular Mercator, neither of those are "equal area" projections, meaning that both will distort areas to some degree (how much is dependent on how far from the tangent line they are). On top of that both use different reference datums.
So yeah, I am not surprised the areas are different.
Cartography 101: every projection distorts something. Distances, angles, areas.
Reprojecting always implies changing something, it's not just a matter of moving and rotating, it has to do with representing the surface of a sphere in some sort of plane. When you change the plane, you change the "perspective".
Just chill, this is normal.
Got it! Thank you so much! :)