If you don't know:

At least it is specific, and he used a "gps" datum, hardly anyone mentions that!

Maybe this was your question, but what's a concrete bound?

Concrete will bind most anything together if you use enough of it.

Concrete Bound

> Maybe this was your question, but what's a concrete bound?
I didn't know either but Bernsten does....

I only use a robot. Does anyone know the conversion from "GPS Datum" to "Robot Datum"? 😉

I think it has to do with the ellipsoid/geoid separation and the conversion between meters and feet. Regardless, both are expresses to the nearest 1/1000th of a foot and accurate to the nearest foot

GPS 29 Or GPS 88 ?

Ellipsoid or Geoid, 03, 09 or 12, meters or feet?

Being from a metes and bounds state, at least I know what a concrete bound is. I guess it is hard to understand a bound in PLSSania.

At best that is a legitimate local datum, no more, no less.

Better than assuming 100.00, not enough information to determine?

Paul in PA

GPS 29 Or GPS 88 ?

The fellow who did the subdivision does not have a GPS. I just was retained to perform a site plan at the end of the road and I will GPS the bound in conjunction just to see how close my 'GPS Datum' is to his... (NAVD 88, Geoid 09, based on NGS 844 7435 B, PID AA7166)

Maybe A Garmin ?

I just did a GPS project with another surveyor and we noted his Tom-Tom GPS position to be within 1" of my Z-12 field indicated position. My field indicated position was within 0.1" of two multiple OPUS-RS positions. He did not record an elevation.

BTW, the ultra-rapid results were 0.004m/0.005m and 0.006m/0.005m so I did not even wait for rapid solutions. The 2:02hr OPUS-S was sloppy residuals (0.035m/0.083m) but was within 0.005m/0.003m SPC of the OPUS-RS.

Paul in PA

Maybe A Garmin ?

> I just did a GPS project with another surveyor and we noted his Tom-Tom GPS position to be within 1" of my Z-12 field indicated position. My field indicated position was within 0.1" of two multiple OPUS-RS positions. He did not record an elevation.

Are you labeling "inches" or "seconds"? Tom-Tom within 1 second is within 100 feet. Specs should put it around 30 feet. I'd expect that precision. The Z-12 would be within 0.1 seconds, or approximately 10 feet. I'd expect that as well. 1 inch or 0.1 inches, however...?? I think not.

JBS

A good opportunity to educate whoever put that on the plan so they do not do it again.

Maybe A Garmin ?

> > I just did a GPS project with another surveyor and we noted his Tom-Tom GPS position to be within 1" of my Z-12 field indicated position. My field indicated position was within 0.1" of two multiple OPUS-RS positions. He did not record an elevation.
>
> Are you labeling "inches" or "seconds"? Tom-Tom within 1 second is within 100 feet. Specs should put it around 30 feet. I'd expect that precision. The Z-12 would be within 0.1 seconds, or approximately 10 feet. I'd expect that as well. 1 inch or 0.1 inches, however...?? I think not.
>
> JBS

That's a good point. My Tom Toms bought years ago (on the advice of Deral) will get position to a second or so but not an inch! They don't give an elevation at all.

That said, they are pretty amazing at repeating x-y precision in the 2-5 meter range for an $88 device. I have used them to get close enough to monuments to find them with a metal detector.

" = Seconds

Sorry to not be specific.

I did not know Tom-Toms don't give elevations. My old Magellans do as well as hand held Garmins, and I thought the car Garmins did also.

Paul in PA