It appears that because of a number of different control surveys done on a large facilities site there are differences vertically of about .3'.
There are a whole bunch of different horizontal systems on site including coordinates from another state, horizontal is pretty easy to deal with, but, the .3' vertical is causing all kinds of issues; can anyone say OPUS?
This looks like the same .3' that showed up about a decade ago with a new OPUS/GEOID model scheme.
Mixing and matching elevations is a bad idea.
I suppose they recorded little or no metadata on the old control? You should be able to convert between geoid models if you know which ones the elevations are from.
Time to bust out with a level?
Lee D, post: 432196, member: 7971 wrote: Time to bust out with a level?
Yeah, waaaayyyyy past time for that, there never, never, never should have ever, ever been any GPS elevations on this site.