Reach accuracy: are GCP needed?


I’m planning to buy the Navio2 FCU with Reach (and eventually ReachRS) antennas.

In case of a setup with Navio2 + Reach (rover on UAV) + ReachRS and base station, would any GCPs required in order to achieve topography-grade surveys?

I may also be interested in surveying medium/large quarries (like 1 km. long and 600 metres wide).

Do we have to add a total station or precision GNSS like Topcon or Leica?

Please let me know, thanks.

@RAW, what accuracy do you want to reach?

Sorry for my late reply but I was out of the office.

I need to reach the same accuracy that I could obtain with classic survey methods, like GCP and total stations.

I must understand if I can get the same accuracy, so I can sell the service to civil engineers or mining and quarrying industry with the same accuracy of traditional methods (or even more, when possible).

Do the GCPs allow to reach better results than RTK/PPK?