GNSS-Total Station Hybrid Survey?
Trying to figure out how to (If it's possible) do a boundary survey using a combination of VRS- RTK and a total station. I understand that I could simply bring control in via RTK and then run the gun off of it. But is it possible to run most of the property corners via RTK and then shoot in the 1 or 2 other corners (Under heavy tree cover) with the gun? What would that look like? Do I call it a GNSS survey or is a standard survey? Or is it something altogether different?
Usually the verbage placed on the map reads " ... I certify that this survey was drawn under my supervision from an actual GNSS survy made under my supervision..." So, Would it be a GNSS survey or not? This is what I'm looking at:
The client is asking for a survey for recombination of 2 properties. I have the deeds and previous survey maps for both properties. Both are referenced to Magnetic North (one in 1968 and the other in 1990) 6 of the 8 corners have been confidently recovered except for 1 that was disturbed and one that looks to be washed out by the creek. My plan was to collect all the recovered corners via RTK (as stated above) and then shoot/reset the others in via TS.
Is the "GNSS" or "standard" qualifier required before "survey"?
I am used to seeing something like "This map correctly represents a survey made by me or under my direct supervision..."
Then in the notes there is something along the lines of:
"This survey was performed with a [insert model here] total station and [insert model here] survey-grade GNSS receivers using corrections broadcast by [insert RTN name here]. Redundant network RTK and total station observations were evaluated and adjusted simultaneously using least squares analysis."
(If you had to pick one or the other, I would lean toward GNSS survey, since the TS positions would be derived from GNSS observations.)
Using GPS for a survey is more about setting up your coordinate system and easily getting on a projection that is tied to an ellipsoid, a worldwide system, the TS is tool similar to the tape measure to get your H.I. Important, but you really don't need to state that you used it during the survey.
Frankly, stating that the survey is GNSS is kinda surveying virtue signaling and irrelevant to the task of retracement, it's the basis of bearings and distances, and the metadata that counts.
But I do know of some regulations that required stating the actual brand and model of receiver used in a GPS survey. One of those now very outdated requirements.
What does the PLS in responsible charge of the work say?
Time for another Star*Net plug. So easy to combine GPS vectors and total station measurements simultaneously. Other LS packages can do it also.
Also a plug for Low Distortion Projections, which make grid scale distortions small enough to ignore.