3 ms·

Can you expand on what the esoteric topic is and its application?

• dagw 12y ago
  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.
  • jimktrains2 12y ago
    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-example-of-the-spatial-relationship-between-a-local-datum-a-global-datum-and-the-geoid-is-represented-in-the-following-figure-wgs84.gif 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.
    • dagw 12y 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.