T3NR Elevation Bust Problem: Calling All Thinkers

[avoidthelloyd]

As painful as it has been, I'm glad I discovered this and it has been addressed. Has anyone used the T3NR as a base and checked that it is fixed? I'm too gun shy to try it... haha. It's a simple test. Measure the HI and start the T3NR as a base, then measure your HR and stake out to the base point while next to it on fairly level ground.

 

[John Rosco]

For all, here are the essential Antenna Phase Center (APC) 'offset information' for several JAVAD 'base' GNSS Receivers:-

Update to Antenna Phase Center (APC) 'offset information' for several JAVAD 'base' GNSS Receivers.

Users can double check at NGS database:
https://geodesy.noaa.gov/ANTCAL/#
All the latest manufacturers antennas and their model names are shown on the NGS website and used by OPUS and other customers worldwide.

 

[John Rosco]

In JFIELD, when you setup the 'Remote Base', do make sure the 'Antenna Type' and also 'offset' are specified and applied to 'the base'.

 

[T.Guisewhite]

Can someone further clarify this with a picture?
I am still haunted by floating vertical errors on projects...I have been thinking it was some of my new help but now I'm still questioning this issue.

If you put a T3NR on a flat surface with the adapter on it, it looks like it should be like I said before the 0.27' offset???

What is the actual ARP on a T3NR and what is the proper offset we should have in the remote base screens?

 

[T.Guisewhite]

Or is this now properly applying the offset of 0.19'???
I am seeing an exact 0.19' error from a total station tie to a base point on a project yesterday.

 

[Matt Johnson]

Can someone further clarify this with a picture?
I am still haunted by floating vertical errors on projects...I have been thinking it was some of my new help but now I'm still questioning this issue.

If you put a T3NR on a flat surface with the adapter on it, it looks like it should be like I said before the 0.27' offset???

What is the actual ARP on a T3NR and what is the proper offset we should have in the remote base screens?

What version of J-Field are you using? If you aren't using at least 4.0.1.665 which is the current release version then it appears you will be affected by the issue in the screenshot I posted above.

If elevation data is important I would always check to make sure your heights look reasonable after starting the base by measuring a point at the same height as the base point next to the base station before you collect any points.

 

[T.Guisewhite]

Current version is 4.0.1.469

I'm fooling with this every way possible...GPS is not tight enough vertical to say what is correct by sitting the pole next to the base and staking it.

When using a "vertical" height measured on the base screen am I correct to say that should be measured to the ARP (Bottom of the 0.08' adapter)?
Then we are applying a +0.19' vertical offset in the setup screen?

 

[T.Guisewhite]

Are you saying we don't need to apply the +0.19' offset anymore?

 

[T.Guisewhite]

Setting the Rover on concrete next to the base
It looks like if we measure to the Bottom of the 0.08' adapter, what I assume to be the ARP
and add +0.27' vertical offset we are getting a decent cut/fill
These screenshots are showing that with and without the 0.27' vertical offset:

 

[John Rosco]

What version of J-Field are you using? If you aren't using at least 4.0.1.665 which is the current release version then it appears you will be affected by the issue in the screenshot I posted above.

If elevation data is important I would always check to make sure your heights look reasonable after starting the base by measuring a point at the same height as the base point next to the base station before you collect any points.

Using JFIELD v4.0.1.665 the Triumph-3NR 'base' antenna APC 'offset' is correctly applied

 

[T.Guisewhite]

Just to confirm my original question.
Once I update to the version 4.0.1.665
The ARP is the bottom of the adapter and no vertical offset is needed?
That last screenshot looks like the ARP is the bottom of the T3NR?
How do I know the adapter is being included in the software?

 

[Matt Johnson]

The ARP is the bottom of the T3NR so you need to include the adapter in the total antenna height or enter its 0.025m height as an offset with pole height.

 

[John Rosco]

Just to confirm my original question.
Once I update to the version 4.0.1.665
The ARP is the bottom of the adapter and no vertical offset is needed?
That last screenshot looks like the ARP is the bottom of the T3NR?
How do I know the adapter is being included in the software?

The Antenna Reference Point (ARP), is the bottom of the Triumph-3NR unit for sure.
Any adapter needs to be included in the 'Pole Rod Height' elevation offset, to the ARP.

 

[T.Guisewhite]

Thanks, I'll verify after doing the update.
Much appreciated.

 

[avoidthelloyd]

Thanks, I'll verify after doing the update.
Much appreciated.

Just measure up to the bottom of the T3NR and use SLANT HEIGHT when you input it if you are using a tape. If you have fixed height pole, it may be true vertical. I haven't had issues since they corrected all this.