I need to correct an erroneous statement I made above. XYZ coordinates are not on the ellipsoid, except by happenstance. They exist in free space whet...

@mightymoe Google Earth is remarkable. Web Mercator uses a sphere with semi-major axis and semi-minor axis equal to the semi-major axis of WGS84 and...

@mightymoe No, see, that's the CAD problem. CAD needs coordinates, but once we reduce state plane distances to the topographical surface, we no long...

@mightymoe Now, Moe, I said above that I wouldn't change anything that's been completed. And you don't have the exact numbers; they're probably with...

@mightymoe Well, that's sort of my idea. I would actually divide each of those separate state plane coordinate lines by its own individual combined ...

@mightymoe OK, I see the problem between individual state plane distances converted to ground and CAD. CAD is itself a plane coordinate system. It n...

@norm Yes. Where there are saddlebacks that aren't swaybacks, it would work fine. As you know, rapid elevation changes kill LDPs and ground coordin...

@norm No problem. Thanks for testing that hastily designed LDP. The topography changes rapidly out west. We have a little of that here, but 5,000 f...

@olemanriver But that's the point of this whole discussion. NAD83 is not designed for measurements on the grid to be equal to measurements on the gr...

@norm I'm close to you on RX0088, I get 4.57 ppm, but we're pretty far apart on RX1056. I think it's west of the airport with distortion of -147.5...

@olemanriver "And yes that would make some properties just shrink in size but it could be done." How would using state plane make a property shrink...

@mightymoe That's what it seems like to me, but I was programming computers before computer science degrees were available at more than a handful of...

@mightymoe The software has the convergence angle and what it needs to calculate the geodetic azimuth and grid azimuth. The rotation is adding or s...