We don't see no steenking multipath!

I watched a survey crew last summer, single rover shot on the control points in the streets, no bipod, then setting the boundary monuments underneath a large overhead billboard.

[sarcasm]Actually the face of that building is so smooth it REDUCES multipath[/sarcasm]

Most don't know any better

>It initializes, so we're good."

I know a lot of other field guys that don't have any understanding of GPS. If it says it's fixed it's good to go.

How does the saying go... with GPS the control is at the pole. If the guy running it doesn't understand how it works then you get crap.

Would be nice to be able to kill the whole "GPS is magic" idea that so many LS's and field guys have. If more people understood the tool they are using there would be a lot less of "well GPS isn't accurate". o.O

We don't see no steenking multipath! Really?

Actually, we rarely see multipath or gps-points out of tolerance when measuring control points in the cities amongst high buildings. (What I call high in Belgium does probably not compare to high at your side!)
We drive our GPS to the limlits ... just to know and recognize these limits. I encourage our people to take shots on the impossible points but always double or triple them with at least a 4 hrs delay between them and if possible not at the same time the next day. Afterwards our control points are always checked with the totalstation with a classic stationing and backsighting on these points and we remeasure or forward statons if gps was not good, we do no resections on these points. It's just one of the ways to get a feel of how far you can go. Conclusion so far is that you can't decide in the field what will be good, second and if needed 3rd measurements are needed to be able to decide if you keep your gps results or switch to total station results.
I have been in places where I hoped that not another surveyor would pass by and think "What the hell is this one trying to do!", but it is likely that this has happened.

Chr.

We don't see no steenking multipath! Really?

Good point. You can always assume that people don't know what they are doing. Sometimes they know exactly what they are doing. But then again sometimes they don't. 😉

We don't see no steenking multipath! Really?

> We drive our GPS to the limits ... just to know and recognize these limits. I encourage our people to take shots on the impossible points but always double or triple them with at least a 4 hrs ....
It is remarkable how good a position you can get at such a site these days. If you follow the multiple occupation procedure you describe you can end up with very precise positions. Unfortunately, none of that routinely happens here. In this instance I had specifically instructed that control be traversed.

And I bet you that very few survey boards in the country are allowed to punish any company for such ridiculous practice.

We don't see no steenking multipath! Really?

:good:

We don't see no steenking multipath! Really?

GNSS positioning saves a near-immeasurable amount of time compared to total station surveys. Reinvesting a fraction of that saved time for redundancy in GNSS positioning presents a near-immeasurable amount of accuracy/reliability over total station surveys when the results prove out, and a near-immeasurable savings in unnecessary corrective measures when the results don't prove out.

We don't see no steenking multipath! Really?

> GNSS positioning saves a near-immeasurable amount of time compared to total station surveys.
I'd agree with you in a lot of cases. In this one, where we are setting points every few hundred feet in an urban canyon, I do not.

We don't see no steenking multipath! Really?

yeah. lots of caveats to that statement that I didn't go into. you're right, close in, I'd take the gun if relative accuracy really matters.