u/Ehbawnyaw

Hi, I was a civil co-op intern last year at a land dev firm and was not early enough in the project to fully learn how control points are established. So I have some questions about the establishment of control points.

Q1: How are control points established? My working theory of surveying is that the GNSS knows its positioning because it's referencing a control point by the base sitting on it. So, how are these control points established? Are they brought in from a known landmark? Is a base set up on a known landmark, then control points are staked out using the landmark as a reference? what if the job site is far from the known landmark? how will that work. Or are they brought in using leveling? or both ?