The land surveyor GPS equipment is REALLY precise.

About 15 years ago I needed to get some property surveyed. Watched the surveyors do their thing. First they set up a gizmo at the town hall were there was a very precise monument. That gizmo sent out signals to their GPS gear telling it how much their error was so that their GPS gear could correct for that error. Error was due to atmospheric conditions, etc. One corner of the property to be survey was a section corner that had a monument. They told me that according to their readings, the section corner monument was off by 0.07 feet, which is less than an inch. Considering how often that section corner had been hit by snow plows over the years, I was surprised they even found the monument. I am guessing the snow plows were the reason for the error. Last time I had seen that monument was years earlier, lying loose on the side of the road.

I took two surveying courses in college, but that was before any of the surveyor equipment used batteries, at that time GPS was something that the Navy used, but just about nobody else did. And yes, at that time the Navy was still using Celestial Navigation. At that time, Loran was still in use for coastal navigation. I was really shocked how much surveying had changed given the new equipment, such as laser distance measurements, etc. In college we learned how to make corrections to the length of a tape measure for temperature, etc. They certainly do not need to do that anymore.