I know they had those points to measure to. It was all kabuki theater back in those days. The elevations gleaned from GPS were very sketchy at best.
Today it's more valid to pay attention to the height measurement, Still, .01' is pushing any GPS measurement for heights and certainly for elevations; <1cm is a very good result.
Not to be a skeptic, but all the many, many miles of levels and GPS (RTK and Static) show the limitations of GPS heights and elevations. They have improved almost to the point of being useful for tight elevation control,,,,,,not quite there yet. I'm still not all that absorbed with measure up on a receiver, do it in feet, do it in meters and if those check it's only what the measure point in the DC is set to that seems to be an issue.
If its trimble, just measure to the specified Notch, extension, etc. etc. etc. Anyone challenging that, is wrong. They build it so idiots can make the measurments work, so if youre wasting time calculating slant height with trimble gear, youre also probably still turning the rover upside down to dump the satellites and not using the technology you paid for. And also, you should sell that stuff to me, I need some gear to do side gig work for unsuspecting consumers wanting their 'pins located' .... 😉
Bring it, I've got my aluminum underware on.
@norman-oklahoma okay but how do you measure up without that gizmo and a leica tribrach adaptor
When I was doing GPSonBM with a ground plane antenna, I used the Trimble stick for slant neasurements.
I made a table for the particular antenna diameter showing the difference between slant and vertical and pasted it in the back of the field book. The table entries were every millimeter or two of the difference over the typical range of setups. Pick the nearest slant values in the table and estinate to 1 mm resolution on the difference.
Then all it took was a subtraction to go from slant measurement to ARP height. No calculator needed.
@davidgstollnemince The OP asked for the “best way” and I’ve given 4 alternatives already. The last 3 aren’t particularly practical, I grant you.
Without the height hook I use a folding ruler to measure the slant as best I can and cut a hundredth. Not perfect, but GPS isn’t all that precise for elevations in any case.