What does a total station measure?

A total station measures horizontal and vertical angles and slope distances (EDM) to a prism or reflectorless surface—then computes 3D coordinates relative to the instrument setup, often tied into site control.

When use a total station instead of GPS?

Use a total station when you need optical line under canopy, tight layout tolerances next to structures, or when GNSS multipath or sky obstruction is severe—common in construction, tunnels, and many boundary jobs.

What is robotic surveying?

Robotic instruments track the prism automatically so one person can operate the instrument and rod—speeding layout and topo on large sites when visibility is maintained.

Total Stations & Robotic Surveying — Prisms, Angles & Layout

Core concepts

Angles: Horizontal and vertical circles measure direction to the target. EDM: Laser or IR measures slope distance—apply atmospheric and prism constants. Resection / backsight: Orient the instrument to site control. Coordinates: Computed from raw observations and height of instrument/target.

Robotic vs manual

Robotic tracking follows a prism for one-person operation. Manual instruments need a second person or frequent moves. Choose based on crew size, site visibility, and budget.

Pair with GNSS

Many firms combine RTK GNSS for control and rapid topo with total station shots for detail under canopy and structure—hybrid workflows are normal.