Carlson GNSS RTK Vectors

Here is the StarNet GPS file:

Where is it getting these bogus heights?

?ÿ

.GPS WEIGHT COVARIANCE

G0 'V1 2017/12/21 14:03:49,(Average) - Base ID read at rover: 0000
G1 _0000-1001?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ 6.587820?ÿ?ÿ?ÿ?ÿ -33.188240?ÿ?ÿ?ÿ?ÿ -39.331570 2.212/2.092
G2?ÿ 4.480000000000E-006?ÿ 1.175000000000E-005?ÿ 1.358000000000E-005
G3 -2.310000000000E-006?ÿ 1.920000000000E-006 -7.430000000000E-006

?ÿ

The G Vectors are ECEF, right?

As Mark indicated, the G1 line contains the XYZ delta values between stations.?ÿ The G2 and G3 lines are vector weights, either as covariances (as in the data shown above) or as standard errors and correlations.

shouldn't the end of the G1 line read 2.100/2.000 instead of 2.212/2.092 ?

It is applying the ARP to L1 Phase Center values to the HI & Rod Values (as it should).

The Vectors are L1 Phase Center to L1 Phase Center.

?ÿ

Loyal

Posted by: Loyal

It is applying the ARP to L1 Phase Center values to the HI & Rod Values (as it should).

The Vectors are L1 Phase Center to L1 Phase Center.

?ÿ

Loyal

I thought so, but wouldn't they be the same offset? both are HiperV receivers.

?ÿ

why would it put a .112 offset to phase center for the base and a .092 offset to phase center for the rover.

Posted by: standing on the corner

Posted by: Loyal

It is applying the ARP to L1 Phase Center values to the HI & Rod Values (as it should).

The Vectors are L1 Phase Center to L1 Phase Center.

?ÿ

Loyal

I thought so, but wouldn't they be the same offset? both are HiperV receivers.

?ÿ

why would it put a .112 offset to phase center for the base and a .092 offset to phase center for the rover.

Good question!

Yes, both HI & Rod "vertical Values" SHOULD be increased the SAME amount (0.0925 meters).

I have to ASSUME that the problem is in the Star*Net RW5 converter.

You can verify what Carlson is doing by solving the BP0001 to PN1001 observation "by hand," which would at least narrow things down to the Converter (I would guess).

?ÿ

Loyal

Here is shows 2.1000 and a phase center correction of 0.0925:
BP,PNBP001,LA39.245469902207,LN-76.465103374896,EL111.7164,AG2.1000,PA0.0925,ATAPC,SRBASE,--

Then here it shows a value of 0.1115 at the ARP. why does it change?
BP,PN_0000,LA39.245469902200,LN-76.465103375000,EL111.6239,AG2.1000,PA0.1115,ATARP,SRROVER,--

Standing,

I have been looking at the RW5 file you posted.

First question: What GEOID Model are you using?

More questions to follow later.

Loyal

?ÿ

Edit: GEOID09?

Owings Mills.gsf N37?ø25'59.0" W078?ø45'00.0" N41?ø23'59.0" W074?ø46'59.0"

custom file created by our Carlson rep

?ÿ

Posted by: standing on the corner

Owings Mills.gsf N37?ø25'59.0" W078?ø45'00.0" N41?ø23'59.0" W074?ø46'59.0"

custom file created by our Carlson rep

?ÿ

I ran a couple of checks, and it appears to be based on GEOID09 (which is fine IF it works in your area).

I'll try and post some calculations (step-by-step through the RW5 file), later today or tonight.

Loyal

?ÿ

Posted by: standing on the corner

shouldn't the end of the G1 line read 2.100/2.000 instead of 2.212/2.092 ?

In this case I believe yes, that will provide the "correct" answer.

It appears that the vector dx/dy/dz in the rw5 file are in fact ARP to ARP, and not phase center to phase center, which the STAR*NET converter is assuming.?ÿ I would contact Carlson to make sure that their vectors are in fact written as calculated to the antenna reference point.?ÿ If confirmed, then in STAR*NET as a workaround you could use the inline option .GPS ADDHIHT to correct the heights for the whole file, but really MicroSurvey should be notified if that's the case so they can fix their converter if required.

Well, I can't explain the odd ƒ??PAƒ? value in line 27 of the (Ver.4.03) RW5 File you posted. I checked several Ver.5.02 RW5 files that I have sitting around, and could not find a similar anomaly in any of them. This may just be a glitch in that particular SurvCE version.

I also ƒ??ranƒ? the vector solution based on the ƒ??knownƒ? data;

Base HI = 2.100m
ARP to L1PC 0.0925m
Rover Rod = 2.000m
dX/dY/dZ vector +6.5878/-33.1882/-39.3316 meters
And the State Plane Coordinate INPUT at the Base (636,882.0927 & 1,374,253.2419 Zone 1900 USSF).

I used the following NGS Online Tools:

NGS Tool Kit
https://www.ngs.noaa.gov/TOOLS/index.shtml

NGS SPC Utilities
https://www.ngs.noaa.gov/TOOLS/spc.shtml

NGS Geoid 09
https://www.ngs.noaa.gov/cgi-bin/GEOID_STUFF/geoid09_prompt1.prl

NGS XYZ Conversion
https://www.ngs.noaa.gov/TOOLS/XYZ/xyz.shtml

This is what I ended up with:

Base GRP SPC?ÿ?ÿ?ÿ 636,882.0927f 1,374,253.2419f?ÿ?ÿ?ÿ 464.7207f NAVD88
Base GRP SPC?ÿ?ÿ?ÿ 194,122.0501m?ÿ?ÿ 418,873.2256m?ÿ?ÿ?ÿ 141.6661m NAVD88
GEOID09?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ -32.1420m 'N'
Base GRP LLH?ÿ?ÿ 39?ø24'54.69902" 76?ø46'51.03376"?ÿ?ÿ 109.5241m NAD83 Eh
Base HI?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ 2.1925m Base HI
Base L1PC LLH?ÿ 39?ø24'54.69902" 76?ø46'51.03376"?ÿ?ÿ 111.7166m NAD83 Eh

Base L1PC XYZ?ÿ +1,128,352.3370m -4,803,529.8325m +4,028,104.7902m
RTK vector?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ +6.5878m?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ -33.1882m?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ -39.3316m
Rover L1PC XYZ +1,128,358.9248m -4,803,563.0207m +4,028,065.4586m

Rover L1PC LLH 39?ø24'53.01754" 76?ø46'51.08292"?ÿ?ÿ 112.8683m NAD83 Eh
Rover Rod?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ -2.0925m Rover Rod
Rover GRP LLH?ÿ 39?ø24'53.01756" 76?ø46'51.08292"?ÿ?ÿ 110.7758m NAD83 Eh
GEOID09?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ 32.1430m 'N'
Rover GRP SPC?ÿ?ÿ 194,070.192 m?ÿ?ÿ 418,872.174 m?ÿ?ÿ?ÿ 142.9188m NAVD88
Rover GRP SPC?ÿ?ÿ 636,711.9549f 1,374,249.7910f?ÿ?ÿ?ÿ 468.8928f NAVD88
Rover GRP RW5?ÿ?ÿ 636,711.9611f 1,374,249.7868f?ÿ?ÿ?ÿ 468.8928f NAVD88
?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ 0.0062f?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ 0.0042f?ÿ?ÿ?ÿ?ÿ?ÿ 0.0000f

As you can see, the above ƒ??hand rolled solutionƒ? agrees (pretty much) perfectly with the SurvCE solution in the RW5 file (give or take a few thousandths of a foot).

This would indicate that SurveCE is using the correct HI+L1 & Rod+L1 values, despite the odd value in Line 27.

Now this probably doesn't really answer your initial question, but it does point out that either the RW5 File, OR the Star*Net converter CONVERSION might need some editing.

Loyal