CTT arrow acting up.....

[Darren Clemons]

I recently purchased another LS strictly for use as a network rover and I was on a job today and my CTT arrow would just not behave. I’d taken several design points from a job I’d done a few years back and was staking and the re shooting them all. The arrow would “generally” get me in the right direction until I got within 6 to 10’ but then would just go all over the place. I do also have left/right and back/forward white boxes as well, but they, of course, show data consistent with where the arrow is pointing.

I did a reboot of the LS, no luck. I recalibrated the compass, no luck.

I’ve used this feature a million times and have never seen it act quite like this, but I am completely new at using the RTN and the VRS, so forgive me. Is there some reason, by chance, that without my own base that feature acts differently?

I’m using a mifi I kept in my pocket for internet connection - maybe somethings throwing off the compass a bit?

 

[Shawn Billings]

Sounds like magnetic interference of some sort.

 

[Matt Johnson]

The arrow would “generally” get me in the right direction until I got within 6 to 10’ but then would just go all over the place. I do also have left/right and back/forward white boxes as well, but they, of course, show data consistent with where the arrow is pointing.

It sounds the GNSS position is from a float solution and jumping around. Is this correct? If the solution is a float solution or jumping back and forth between fixed and float then of course the direction of the CTT arrow will jump around when you are close to the target point. If there is a problem with the compass then you should see the displayed azimuth in the middle box at the top of the screen behaving sporadically.

 

[Darren Clemons]

Fixed solution out in wide open. I could even see a couple of the points I was walking towards. The arrow would point straight ahead as I walked up to it until I got within 10’ of the point, then as I’d slowly inch closer, the arrow would turn 90 or even 180 degrees.
It must’ve been what Shawn mentioned and some sort of magnetic interference specific to this site.

 

[Darren Clemons]

I still am having issues with this on a new LS I’ve just purchased. I’ve checked that all my settings are the same as my other units, I’ve calibrated the compass multiple times and no matter what, the CTT arrow and the left/right and back/forward white boxes are just very odd and irregular.
It does act like Shawn mentioned in that it reacts as if there’s tremendous magnetic interference but it’s happened on multiple sites now.
Michael and Eugene have looked at it a bit on RAMS this weekend but I’m afraid there’s no way to replicate its behavior sitting still on a desk.
Anyone have any clue as to what this could be or if something could be faulty in the new LS?

I am going to take it out as a second rover tomorrow and compare it’s compass readings and the staking functions directly beside another unit.

 

[Matt Johnson]

Can you post a video of the problem?

 

[Matt Johnson]

Also share a project archive which this is occurring in.

 

[Nate The Surveyor]

Is the calibration up to date, where you set the ls on
Bottom
Top
Right side
Left side
Etc?

 

[Matt Johnson]

The arrow would point straight ahead as I walked up to it until I got within 10’ of the point, then as I’d slowly inch closer, the arrow would turn 90 or even 180 degrees.

I have a few more questions. Did the DTT box read 0.0 when you were on the point? Is your base reference frame setting set to NAD83 2011?

 

[Nate The Surveyor]

Do you have any strong magnets on you?
Like the ones that hold cell phone cases shut?
Do you have your cell phone real close to the LS?
Do you carry your LS REAL close to a big speaker (with big magnet in the back)?
All these things can contribute.
N

 

[Darren Clemons]

I have a few more questions. Did the DTT box read 0.0 when you were on the point? Is your base reference frame setting set to NAD83 2011?

Yes and yes.

 

[Darren Clemons]

Do you have any strong magnets on you?
Like the ones that hold cell phone cases shut?
Do you have your cell phone real close to the LS?
Do you carry your LS REAL close to a big speaker (with big magnet in the back)?
All these things can contribute.
N

Nothing different than I've ever had on me when using our other 3 LS's Nate. There's something different with this machine and there has been since the first day I used it.
A small unnoticed setting I've overlooked or something faulty in the LS itself - it has to be one of those two things.