undefined | Better HN

0 pointsdagw11y ago0 comments

Translating between coordinate systems and basically anything that involves mapping and measuring in 3 dimensions on an irregular not-quite-spherical surface is really hard to get right.

0 comments

2 comments · 1 top-level

jimktrains211y ago· 1 in thread

I didn't make this picture, but it gives a good idea on the "irregular not-quite-spherical surface" part.

http://alienspacesciencenews.files.wordpress.com/2013/10/an-...

The Local Datum could be NAD83 or what-have-you based on where you are on the surface. Using the local datum gives better distance measurements and more accurately can represent elevation.

dagwOP11y ago

That's a pretty great image. I'll have to remember it for next time someone asks why is all this so hard and can't we just use WGS84 for everything.

j / k navigate · click thread line to collapse