RTK PPK and NGS Coordinates

[knottrw]

We tied a NGS Benchmark about 4,300’ Away from our Base Location (not the best, but not the worst) last week. We shot the Benchmark 4 times in succession with the TLS+Min1Eng Medium Profile. It was the end of a long day and the RTK Value of shots 2-4 all agreed with each other within .04 so we packed up and called it a day. We returned to the office the next day and DPOSED.

Results:

Shots 2-4 Shifted RTK Values all agree with each other but are roughly ΔH 2.20’ ΔV 3.50’ away from the Coordinate Values reported by NGS.

Shots 1-4 PPK Values all agree with each other and are roughly ΔH 0.23’ ΔV 0.20’ from the Coordinate Values reported by NGS.

Horizontal: NAD83 California Zone 2 US Foot
Vertical: NAVD88 (2011)

Any Ideas on what is happening? Can we trust the PPK?

 

[Michael Stazhkov]

We tied a NGS Benchmark about 4,300’ Away from our Base Location (not the best, but not the worst) last week. We shot the Benchmark 4 times in succession with the TLS+Min1Eng Medium Profile. It was the end of a long day and the RTK Value of shots 2-4 all agreed with each other within .04 so we packed up and called it a day. We returned to the office the next day and DPOSED.

Results:

Shots 2-4 Shifted RTK Values all agree with each other but are roughly ΔH 2.20’ ΔV 3.50’ away from the Coordinate Values reported by NGS.

Shots 1-4 PPK Values all agree with each other and are roughly ΔH 0.23’ ΔV 0.20’ from the Coordinate Values reported by NGS.

Horizontal: NAD83 California Zone 2 US Foot
Vertical: NAVD88 (2011)

Any Ideas on what is happening? Can we trust the PPK?

Please sent the project to support for investigation (Projects screen on LS -> "Send Project to Support" button) and tell the device serial number or the project name.

 

[knottrw]

Please sent the project to support for investigation (Projects screen on LS -> "Send Project to Support" button) and tell the device serial number or the project name.

20206001_Gps1 LAS

 

[Alexey Razumovsky]

We need coordinates reported by NGS as well

 

[knottrw]

N: 6,284,995.04' E: 1,950,099.14' U:62.0'
PID: JT9634 DESIGNATION: HPGN D CA 04 RS

 

[Shawn Billings]

WGS84 vs NAD83

 

[Alexey Razumovsky]

We've rechecked DPOS coordinates manually. In fact, they are about in ΔH 0.23’ ΔV 0.20’ apart from NGS JT9634 datasheet :
SPC CA 2 North - 1,950,099.14 ; East 6,284,995.04 sFT. I would recommend to visit the benchmark once more. Put receiver directly on it. ReDPOS. One hour session would be enough.