Community Forum

Imported Survey Points (Control Points) seem to be slightly off 6-10 inches

(Tanna James) #1

I have imported a .csv into my survey mode that were uploaded from an existing survey. When I try to stake out the points it seems that the rover is bouncing around a lot and seems like its not getting a great fix. What settings should I adjust to get this more precise? In my mind it should be a few cm accuracy?

The photo attached is where the survey brought me to and it is supposed to be right at the corner of the bricks… Please let me know what to adjust. Thanks!

(A Walker) #2

How was your base station setup?
Is it over an arbitrary point?
Is there now something in the vicinity of the base station that could cause interference?
Did you place the base station over a known point and then type in the coordinates of the known point?
Are your coordinates from your previous survey in WGS84?
Is it consistently out in the same direction and distance?

(Michael Lambert) #3

On @tanna.j behalf. Base was on a known point that was manually entered. Coordinates are WGS84. Inconsistent error because of a weak fix.

(Christian Grüner) #4

Do you have an image of the surroundings?
Can you make screenshots of the Status screen and RTK options?

(Michael Lambert) #6

Here’s some of it. @tanna.j will have to supply the rest.


Base RTK (incomplete)

Rover RTK (incomplete)

Environment (only 2D)

(Michael Lambert) #7

Issues are in conjunction with this, but even after RTK was acquired.

(Christian Grüner) #8

That baseline is way too long? Is that a mistake or?

(Michael Lambert) #9

That can be ignored. It was a remnant from the other post where the base had been set in XYZ and the control points were imported in LLH. Returned base to LLH and that’s how the fixed issue was resolved. Now we have this thread…

(David Hofer) #10

Yes that baseline looks similar to another post on the forum here

(Christian Grüner) #11

How is the base coordinates derived?


Try continuous mode. False fix and hold?

(Tanna James) #13

Here are the remaining photos of the current status and settings…

(Christian Grüner) #14

With that SNR, a false fix would be unlikely I would think. Still, worth the try.

(Christian Grüner) #15

That baseline is very short. Can you try with something a bit longer? 30-50 meters instead?


Easy troubleshooting.
Do the same thing one more time. Survey one point, wait 20-30minutes. If you survey the same point and get the same data your FIX is golden.
Now, if you do the same whith stakeout, this would almost rule out fals FIX as the reason for misplaced points.
What you are left with then is error in your coordinate format.


Does having the base positioning mode set to kinematic as shown rather than static in RTK have any effect on positioning when manually entering a base coordinate?

(Christian Grüner) #18

Nop, none.


Only if you have your base using correction input for e.g a vrs service or a long range static measure


That was my assumption, thanks.

(Timd1971) #21

Obviously the baseline has changed substantially from way too far out (14481 km???)(were u using ntrip cors settings? Maybe this is cause for error?) to about 6’ apart.

Should get better readings now. Try and see what you get with the shorter baseline.