and_viceversa

3 ms·

1. 1.▲
   by and_viceversa 4y ago

   With a dual band survey grade receiver, WGS84 coordinates can be derived to 2cm accuracy in the vertical [0] and even better in the horizontal. WGS 84 is a time dependent datum - each addition to the ensemble is known as a realization. The
2. 2.▲
   by and_viceversa 4y ago

   For a U.S. analog, we use the State Plane system. The states have (multiple) custom projections to suit local accuracy needs. Like another commenter said, WGS 84 uses ellipsoidal coordinates that are not suitable for the Crossrail's co
3. 3.▲
   by and_viceversa 6y ago

   After more than a decade of lurking HN... this is the comment that compels me to create an account. Schwab dropped this ball and left me in the Guatemalan jungle for 18 days after many assurances that they would definitely not send the new