Verifying height position to known datum …

Looking to achieve the best elevation accuracy with GNSS Machine Control…
So I…
Set up a 1” total station (MS60) over a known point
Checked a control point’s elevation with the instrument..
Placed the machine bucket on the same point…
Tweaked the GNSS elevation offset 10mm to get the best possible match - verifying the height position. (This should only be used for minor adjustments)
Excavated a small section of foundation…
Checked excavation with the same instrument on the original setup..
Got very good results for a 25T machine..
A base station, new machinery and sandy ground all helps… although the sand has literally no resistance, so sneeze and you’ve over-dug by 200mm 👍🏻kdjc