Combined use of GNSS and Total Station

You can use a Total Station placing it on a point measured with GNSS receiver, in nRTK mode.
In this case you have a 2D precision of around 2/3 cm.
Or, better said, related to the precision of the GNSS receiver.

Every other point that you collide and detect with the total station will have a similar precision (unless any instrumental errors), even if the precision of the total station is capable to reach just few millimeters.

Total station allows you to detect points that are not accessible on foot.
You will not use the reflective prism and just go with laser measurement.
There points are not accessibile by an operator with a satellite antenna mounted on a pole.
They could be too dangerous to go.
Or even simply impossible to reach.

If you make a GNSS survey and place targets on the ground (as for this aerial photogrammetric survey in a white marble quarry) you can orient the total station using different points whose coordinates you know.

If this precision is ok for your purposes, this is an excellent and fast method for having a good distribution of Ground Control Points and Check Points in the area you’re working in and that has a predominantly vertical development.

Or you can also use it to measure points’ coordinates that you would not otherwise be able to see in the photos of a photogrammetric flight: vegetated and covered areas.

Ciao!

Paolo Corradeghini