POSC Specifications Version 3.0 |
Epicentre Standard Values ref_vertical_datum |
identifier | description | source | version | status |
---|---|---|---|---|
ref _version .identifier | ||||
geoidal | The datum is based on a gravity, isopotential surface. | POSC | epicentre 3.0 | current |
ellipsoidal | The datum is the ellipsoid surface of the horizontal geodetic datum. | POSC | epicentre 3.0 | current |
general vertical reference datum | The datum is a widely recognized description of a surface that is defined, usually by statute, to define the zero elevation surface. | POSC | epicentre 3.0 | current |
local | The datum is a local marker, which is used for convenience in a particular survey or close set of surveys. It is generally not recognized by any standards or legal body, but may be. Examples would be a particular point on a drilling rig, a particular rock in a survey area, or a USGA benchmark. | POSC | epicentre 3.0 | current |
unknown | It is not known what type of vertical datum this is. | POSC | epicentre 3.0 | current |