astrodanco, post: 353930, member: 7558 wrote: NGS and IGS modelied phase center offsets from the ARP of my old Zephyr Geodetic antenna are different from what Trimble specifies
That's true for all of the Trimble antennas I've worked with. As long as you don't mix offset sources, I figure the differences cancel out.
It's good JaRo brings this issue up, every GPS RTK or Static user should be checking their units to actual level data..............
Kinda seems basic, but I think many don't.
MightyMoe, post: 353952, member: 700 wrote: It's good JaRo brings this issue up, every GPS RTK or Static user should be checking their units to actual level data..............
Kinda seems basic, but I think many don't.
I have a set of matched R8 GNSS units but a check is a good idea.
vern, post: 353955, member: 3436 wrote: I have a set of matched R8 GNSS units but a check is a good idea.
The R8's work really well, the R10's are even better.
I suppose we are "lucky" having so much level control on points, day starts with setting the GPS base on a control point and checking into a nearby control point, often it's a leveled pair of points, and with the R10's we usually are very close to record. We also do the reverse, set on GPS and cross check with the S6, again expecting less than .03'.
Can't know why JaRo is having these issues, but I do mix trimble receivers and don't have them.
I would sure figure it out, it's good he's looking at it.
You don't want a tenth sitting there before starting every job.
I got my hands on the R10 yesterday but they forgot to bring the charger. I think I will set another post and run all three at the same time, base and two rovers on two different data collectors.
Thanks for all the advice.
James
Could someone please take a look at this and explain to me what I am looking at?
This is the calibration info for my Trimble Zephyr Geodetic 57971.
I got this from the igs08.atx file. I am assuming there are 4 sets of data, GPS L1, GPS L2, RUSSIAN L1, RUSSIAN L2.
If I have that part right, then at the start of each set is this
+1.11 -0.32 +66.77 NORTH / EAST / UP (for G01 and R01)
+0.07 +0.66 +57.79 NORTH / EAST / UP (for G02 and R02)
Is it 66.77 mm vertical offset for the L1 frequencies and 57.79 mm for the L2 frequencies?
How are those two combined?
Thanks,
James
FROM THE FILE.....
START OF ANTENNA
TRM57971.00 NONE TYPE / SERIAL NO
ROBOT Geo++ GmbH 8 03-APR-13 METH / BY / # / DATE
5.0 DAZI
0.0 90.0 5.0 ZEN1 / ZEN2 / DZEN
4 # OF FREQUENCIES
IGS08_1882 SINEX CODE
Number of Calibrated Antennas GPS: 008 COMMENT
Number of Individual Calibrations GPS: 016 COMMENT
Number of Calibrated Antennas GLO: 014 COMMENT
Number of Individual Calibrations GLO: 028 COMMENT
# GLONASS PCV COMMENT
# derived from Delta PCV per 25.0 MHz COMMENT
# for frequency channel number k=0 COMMENT
G01 START OF FREQUENCY
+1.11 -0.32 +66.77 NORTH / EAST / UP
NOAZI +0.00 -0.04 -0.16 -0.35 -0.61 -0.94 -1.34 -1.76 -2.16 -2.48 -2.63
0.0 +0.00 -0.03 -0.13 -0.31 -0.57 -0.90 -1.33 -1.81 -2.30 -2.72 -2.97
(2 pages of data deleted)
G02 START OF FREQUENCY
+0.07 +0.66 +57.79 NORTH / EAST / UP
(2 pages of data deleted)
R01 START OF FREQUENCY
+1.11 -0.32 +66.77 NORTH / EAST / UP
(2 pages of data deleted)
R02 START OF FREQUENCY
+0.07 +0.66 +57.79 NORTH / EAST / UP
I know there's something in this, I just haven't figured out what it is or where it's at! 🙂
Comparing the vertical offsets for several receivers/antennas between the trimble antenna.ini file and the igs08.atx file, this is what I think I have.
Trimble Zephyr Geo Mod, 2 57971
antenna.ini 8.546cm - igs08.atx 66.77 mm for L1 / 0.0613 ft difference
R10
antenna.ini 14.91cm - igs08.atx 128.36 mm for L1 / .0680ft difference
SPS985
antenna.ini 14.44cm - igs08.atx 123.50 mm for L1 / .0686ft difference
R8GNSS/SPS88x
antenna.ini 6.49cm - igs08.atx 83.67 mm for L1 / -0.0616ft difference, that's negative, as in .06ft the other direction.
Surely I am missing something, comparing apples to claw hammers or something.
I still plan on comparing the borrowed R10 with my receivers but I have to get the wideband/narrowband issue worked out first.
I wish I could run them thru Opus Projects but that class is still 2 weeks away.
James
Just my 2-bits, BUT
My FIRST RULE when mixing GPS Antennas, is simple:
DUMP whatever manufacturer "Nominal Phase Center" values you have in your data collector (or desktop/laptop processing software), and REPLACE them with the IGS Absolute Calibration data!
I suspect that some OEM software ASSUMES that you will never mix n match antennas, so "they" don't really worry too much about these nominal numbers. As has been mentioned before, IF you use the SAME antenna model at BOTH ends of a vector, then the phase center models don't really mean much (if anything).
Loyal
Loyal, post: 357136, member: 228 wrote: REPLACE them with the IGS Absolute Calibration data!
I agree, though I note that the process may not be bulletproof. There's something goofy going on with the Javad Triumph-2 antenna model and OPUS. It's not clear yet whether it's the model itself, or the way OPUS applies it, or some sort of end-user error, or something else entirely, but some people are finding discrepancies consistent with the 25 mm adapter used to attach the T-2 to a standard 5/8-11 mount.
Here ya Jim,
This is why I think that it makes perfect sense to "peg" your own antennas and verify the L1 PH "offsets" generated by the IGS.
Many folks run [say] Zephyr Base Antennas and [say] R8 rovers, and that IS one of the combinations that have a non-trivial variance between the Trimble "nominal" and the IGS Absolute.
Loyal
I actually did a real world test on this last week, I set a point (control point #1) in 2011, cors reduction, using a 4700 reciever, I set a monument using a 5800 reciever, Set a control point in 2014 (control point #2) about 5 miles west, no connection between them beyond cors reductions using the same numbers for the cors.
last month a a colleague set control point #3 from control point #2-3 miles south of point #1.
Last week he located my monument and hit it .02' hor, .02' vert.
He has a 5700 base with a zepher antenna, my base is a 4700 with a L1L2 antenna, my rover is a 5800, his is a R-8(2).
4 different antennas mixed and matched all returning the same values. It does work.
For this work there is no levels, but the antennas are in sync.
I'm still not any closer to figuring out my problem. For the time being I have been changing my rod height by .08 ft.
This week I had a chance to set three receivers in a 12 foot area, wide open above 15 degrees, with each jam nut precisely level. It's not the same area as the first picture. It's a corner brace post with 3 pipe post and an all-thread clamped to each post. I logged three files and run it thru opus projects. This is my first session with opus projects since taking the Opus Projects Managers Webinar about 3 weeks ago so I could have easily missed something. (Thanks to Dan Martin for the excellent class)
Antenna heights for this was zero for the 57971 and the SPS881. For the R10 I put in a height of 0.050 for the quick connect. Taking out the .05 would actually make it worse.
This is what I got back:
MARK: 2320 (Zephyr Geodetic Mod 2 57971)
REF FRAME: NAD_83(2011) (2010.0000) IGS08 (2016.2009)
X: -532891.278 m 0.001 m -532892.083 m 0.001 m
Y: -5381787.504 m 0.003 m -5381786.059 m 0.003 m
Z: 3370169.186 m 0.002 m 3370169.013 m 0.002 m
LAT: 32 06 10.49682 0.001 m 32 06 10.51549 0.001 m
E LON: 264 20 42.52777 0.001 m 264 20 42.49180 0.001 m
W LON: 95 39 17.47223 0.001 m 95 39 17.50820 0.001 m
EL HGT: 122.652 m 0.003 m 121.409 m 0.003 m
ORTHO HGT: 148.581 m 0.012 m (H = h - N WHERE N = GEOID12B HGT)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
MARK: 5211 (R8 GNSS/SPS881)
REF FRAME: NAD_83(2011) (2010.0000) IGS08 (2016.2009)
X: -532889.345 m 0.001 m -532890.150 m 0.001 m
Y: -5381788.296 m 0.003 m -5381786.851 m 0.003 m
Z: 3370168.186 m 0.002 m 3370168.013 m 0.002 m
LAT: 32 06 10.45901 0.001 m 32 06 10.47769 0.001 m
E LON: 264 20 42.60411 0.001 m 264 20 42.56814 0.001 m
W LON: 95 39 17.39589 0.001 m 95 39 17.43186 0.001 m
EL HGT: 122.627 m 0.003 m 121.384 m 0.003 m
ORTHO HGT: 148.556 m 0.012 m (H = h - N WHERE N = GEOID12B HGT)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
MARK: 6169 (R10)
REF FRAME: NAD_83(2011) (2010.0000) IGS08 (2016.2009)
X: -532889.468 m 0.001 m -532890.273 m 0.001 m
Y: -5381789.564 m 0.003 m -5381788.119 m 0.003 m
Z: 3370166.315 m 0.002 m 3370166.141 m 0.002 m
LAT: 32 06 10.38558 0.001 m 32 06 10.40424 0.001 m
E LON: 264 20 42.60421 0.001 m 264 20 42.56821 0.001 m
W LON: 95 39 17.39579 0.001 m 95 39 17.43179 0.001 m
EL HGT: 122.712 m 0.003 m 121.469 m 0.003 m
ORTHO HGT: 148.641 m 0.012 m (H = h - N WHERE N = GEOID12B HGT)
One thing I should point out, The NGS Relative and the Absolute values are the same for the R10 but are different by 18-20 mm on other antennas I have checked
James
JaRo, post: 362627, member: 292 wrote: I'm still not any closer to figuring out my problem. For the time being I have been changing my rod height by .08 ft.
This week I had a chance to set three receivers in a 12 foot area, wide open above 15 degrees, with each jam nut precisely level. It's not the same area as the first picture. It's a corner brace post with 3 pipe post and an all-thread clamped to each post. I logged three files and run it thru opus projects. This is my first session with opus projects since taking the Opus Projects Managers Webinar about 3 weeks ago so I could have easily missed something. (Thanks to Dan Martin for the excellent class)
Antenna heights for this was zero for the 57971 and the SPS881. For the R10 I put in a height of 0.050 for the quick connect. Taking out the .05 would actually make it worse.
This is what I got back:
MARK: 2320 (Zephyr Geodetic Mod 2 57971)
REF FRAME: NAD_83(2011) (2010.0000) IGS08 (2016.2009)
X: -532891.278 m 0.001 m -532892.083 m 0.001 m
Y: -5381787.504 m 0.003 m -5381786.059 m 0.003 m
Z: 3370169.186 m 0.002 m 3370169.013 m 0.002 m
LAT: 32 06 10.49682 0.001 m 32 06 10.51549 0.001 m
E LON: 264 20 42.52777 0.001 m 264 20 42.49180 0.001 m
W LON: 95 39 17.47223 0.001 m 95 39 17.50820 0.001 m
EL HGT: 122.652 m 0.003 m 121.409 m 0.003 m
ORTHO HGT: 148.581 m 0.012 m (H = h - N WHERE N = GEOID12B HGT)+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
MARK: 5211 (R8 GNSS/SPS881)
REF FRAME: NAD_83(2011) (2010.0000) IGS08 (2016.2009)
X: -532889.345 m 0.001 m -532890.150 m 0.001 m
Y: -5381788.296 m 0.003 m -5381786.851 m 0.003 m
Z: 3370168.186 m 0.002 m 3370168.013 m 0.002 m
LAT: 32 06 10.45901 0.001 m 32 06 10.47769 0.001 m
E LON: 264 20 42.60411 0.001 m 264 20 42.56814 0.001 m
W LON: 95 39 17.39589 0.001 m 95 39 17.43186 0.001 m
EL HGT: 122.627 m 0.003 m 121.384 m 0.003 m
ORTHO HGT: 148.556 m 0.012 m (H = h - N WHERE N = GEOID12B HGT)+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
MARK: 6169 (R10)
REF FRAME: NAD_83(2011) (2010.0000) IGS08 (2016.2009)
X: -532889.468 m 0.001 m -532890.273 m 0.001 m
Y: -5381789.564 m 0.003 m -5381788.119 m 0.003 m
Z: 3370166.315 m 0.002 m 3370166.141 m 0.002 m
LAT: 32 06 10.38558 0.001 m 32 06 10.40424 0.001 m
E LON: 264 20 42.60421 0.001 m 264 20 42.56821 0.001 m
W LON: 95 39 17.39579 0.001 m 95 39 17.43179 0.001 m
EL HGT: 122.712 m 0.003 m 121.469 m 0.003 m
ORTHO HGT: 148.641 m 0.012 m (H = h - N WHERE N = GEOID12B HGT)One thing I should point out, The NGS Relative and the Absolute values are the same for the R10 but are different by 18-20 mm on other antennas I have checked
James
James,
Any chance that you would send me your RINEX files for this last exercise?
I would like to play around with the data tonight, and see what (may or may not) shake out.
Loyal
LDOGEO at AOL period COM
Loyal, post: 362636, member: 228 wrote: James,
Any chance that you would send me your RINEX files for this last exercise?
I would like to play around with the data tonight, and see what (may or may not) shake out.
Loyal
LDOGEO at AOL period COM
I would be tickled pink to have you look at it. I know it's an issue of heights from the ARP to the phase center, I just can't figure out which one is right. Give me about 30 minutes and I will write up what I think I know so far.
James
