|
GPS is very good on location of X and Y with in 0.01/3 of a foot time after time
not so much on Z elevation for a lot of odd reasons inc the MOON [tides on land !] can be off more then a 0.2 of a foot correct level run should check in at under 0.03
level runs I have done too many miles
and found government bench marks out [beach sand bars are not real stable even after built up
the tool to do accurate levels is not GPS OR A THEODOLITE but a good old fashion level and a fancy stick new stuff self reads and records but looking and reading the numbers works fine
streets are layed out to elevation center line or back of sidewalk if one should be known
if sanitary sewers the manhole are dead accurate and known/listed
a house plan should have a floor elevation listed
if you do not have any of that you can find listed
GUESS it can't be too far off and who will check ?
|