I've got 10 minutes of overlapping data between my base and rover, on a particular point, trying to get as good a solution as I can from Trimble Business Center. Base had good open sky. Rover only partial sky. I know I shouldn't expect too much.
I've imported the data, and have processed the baselines. Using the session editor for the baseline in question, I can see that there were 8 GPS satellites and 7 GLONASS satellites with observed data common to both the base and rover. As far as I know I haven't done anything to restrict processing (to GPS only, for example).
Yet, when I view the baseline processing report, it looks like only 6 satellites were used in the solution, all GPS satellites. In the section of the report entitled Tracking Summary, all 15 satellites (8 GPS and 7 GLONASS) are shown, but only six of the satellites are "highlighted" so to speak with a light colored band across applicable portions of the base and rover data. Following the Tracking Summary, the section of the report entitled Residuals, shows graphs of residuals over time, but again only for the 6 satellites highlighted in the Tracking Summary.
I'm guessing that the GLONASS data that was observed was rejected on the basis of its being too noisy, or for other reasons, but how do I know for sure why certain data was accepted or rejected?
Al
Before you process the baselines, on the left side of the screen under "Sessions", right click on each baseline and look at the "Session Editor". My guess is that you don't have Glonass data for one of the points.
You can verify that by comparing the Glonass data to the GPS data for each satellite. If that is the case, the GPS sat's will show a green and a blue line for each satellite and the Glonass sat's will show just a green line. The problem is that you only collected GPS data on one of the points.
Hi, David, and thanks for your help. I cleared the processing results I had performed earlier, and was able to view the session editor for the baseline as pre-processed. I see both blue and green bars for 7 GLONASS satellites in the session editor, so it appears as if I've got GLONASS data at both the base and rover for this session.
Ok, since we know you have the required data, it has to be in the settings somewhere. Open "Project Settings" and click "Baseline Processing", then check "General", "Processing" and "Satellites", then check that you have the appropriate settings so that it doesn't ignore the Glonass data.
Can You Check The Quality Of Your Data In TBC ?
Were I ahving this problem in Solutions I would be checking my raw data for each position/satellite and the residuals of the solutions.
I immediately can see if I am expecting too much from what I have.
Also verify the commonality of your sattelites. Even if there is just one odd satellite at each position, it pays to download the nearest CORS data and throw that into the mix. Getting CORS Glonass would be nice, but just one odd GPS common from each position to a nearby CORS can improve your solution.
The next thing is to raise or lower your mask angle. Lowering can add a sattelite or two. Raising may weed out a poor sattelite.
Paul in PA
I've never used GLONASS in post processing (don't have GNSS receivers), so I might be out in left field (drunk in the bleachers):
You might want to check the .sp3 file that was downloaded by TBC.
Does it contain GLONASS data?
Here's a clip from yesterday's file:
[inlinecode]/* ULTRA ORBIT COMBINATION 17196_06 (56283.250) FROM:
/* cou emu esu gfu gou ngu siu usu coR esR gfR
/* REFERENCED TO emu CLOCK AND TO WEIGHTED MEAN POLE:
/* PCV:IGS08_1719 OL/AL:FES2004 NONE Y ORB:CMB CLK:CMB
* 2012 12 21 6 0 0.00000000
PG01 -2674.781087 -15038.237466 -21751.502266 288.680114 8 10 8 84
PG02 -18268.992971 14418.090552 12471.922870 412.186383 8 11 8 171
PG04 -26105.800831 5610.237498 -1313.602068 81.373476 9 11 4 202
PG05 -6258.471781 15047.806201 20918.693972 -374.034128 9 8 6 203
PG06 13647.624653 -18773.526321 12702.563492 417.042901 10 8 9 137
PG07 -18317.364174 -8037.028687 17658.953752 159.532161 6 8 8 216
PG08 -25589.248094 -1689.090136 8106.290448 3.593306 4 9 6 187
PG09 -8312.340986 15931.401900 -20108.258480 208.110955 11 9 7 158
PG10 -19578.041823 -2199.601004 17720.296580 -63.030906 8 7 8 209
PG11 2403.938450 -19039.319524 -18690.044338 -335.384452 9 9 5 170
PG12 9246.743659 21959.074460 -11958.842147 108.003686 9 5 7 195
PG13 -7504.407084 -16256.045315 19442.444028 158.588667 9 9 5 150
PG14 15852.894890 -2139.542288 -20980.073648 218.557241 7 9 11 196
PG15 -3686.414127 25867.103787 -3978.585498 -102.805177 9 7 6 210
PG16 6998.914453 -13772.293618 21548.432206 -251.036001 9 4 8 115
PG17 -16159.295432 3644.065134 -20511.824999 67.395711 8 8 5 220
PG18 20778.377917 15817.397139 -5400.862351 230.432887 9 9 7 205
PG19 7994.378430 -25002.887277 -2230.348616 -332.794312 5 8 8 190
PG20 -10929.172575 -21629.025386 -11126.635952 77.175723 7 9 6 169
PG21 21546.533751 6267.032279 15145.946215 -269.638842 5 8 8 174
PG22 20761.539169 4515.163099 -15832.271324 153.813316 10 8 7 184
PG23 -1353.677869 -23721.798066 11525.823386 131.954449 8 6 7 194
PG24 -1579.404636 15817.519578 -21273.388261 1.990699 10 11 7 215
PG25 17987.794202 19558.301200 -1278.322814 57.723429 8 3 7 135
PG26 -12759.999115 22143.811410 5878.978687 -167.406676 10 14 13 219
PG28 -20400.721602 -9593.714908 -13628.524393 215.956206 10 12 9 137
PG29 7740.728828 17376.573061 18604.591757 389.637337 10 9 4 228
PG30 15533.425725 -5538.437178 20463.557322 -277.704166 10 9 8 236
PG31 25213.626535 -8145.740907 3521.125842 293.394570 7 9 8 211
PG32 -1944.765287 -20946.467527 -16354.099875 -518.824160 9 6 7 162
PR01 -15018.829137 -19602.382180 6438.459055 999999.999999 12 13 15
PR02 -14428.689414 -4951.579560 20449.946409 999999.999999 14 14 12
PR03 -5636.514869 11239.918895 22230.125058 999999.999999 16 15 8
PR04 6657.725672 21901.945578 11263.847458 999999.999999 9 11 8
PR05 14997.933142 19639.865821 -6315.401108 999999.999999 4 4 12
PR06 14543.919005 5630.508690 -20210.364214 999999.999999 8 7 11
PR07 5614.714662 -11224.653063 -22175.813879 999999.999999 14 15 6
PR09 25558.084083 95.057992 185.865018 999999.999999 8 12 15
PR10 18565.415488 -7195.117739 15882.603116 999999.999999 13 10 12
PR11 719.318705 -10576.826721 23207.122080 999999.999999 18 14 13
PR12 -18151.765822 -7686.229910 16266.548944 999999.999999 13 15 18
PR13 -25512.871631 203.091613 -58.378069 999999.999999 11 14 18
PR14 -18618.257350 7235.124420 -15925.102112 999999.999999 17 14 15
PR15 1554.948836 10396.772095 -23229.991557 999999.999999 14 11 12
PR16 18232.645334 7603.372904 -16108.137217 999999.999999 9 11 11
PR17 -14786.610735 19878.231143 -5978.208167 999999.999999 11 9 14
PR18 -6533.081058 21900.805041 11451.499737 999999.999999 8 11 10
PR19 6366.329675 9965.767139 22596.449516 999999.999999 6 10 11
PR20 14936.968101 -7518.704943 19243.345369 999999.999999 8 17 16
PR21 14883.059136 -19876.609321 6053.706142 999999.999999 13 14 16
PR22 6606.697220 -21892.495351 -11153.203931 999999.999999 14 10 13
PR23 -5699.807326 -11062.505288 -22277.805569 999999.999999 14 10 11
PR24 -14343.207797 5741.495943 -20320.532527 999999.999999 11 14 10[/inlinecode]
If you don't have the "PR" (GLONASS data), then maybe that's the problem (I dunno).
You can get the GPS+GLONASS .sp3 files here:
ftp://cddis.gsfc.nasa.gov/glonass/products/
Just a thought,
Loyal
Edit...now that I've got the "code" to display...I don't really savey the whole GLONASS thing, and maybe you will need to wait for the IGS FINAL orbits for a good GLONASS/GPS Combinations. Again...I dunno!
> Ok, since we know you have the required data, it has to be in the settings somewhere. Open "Project Settings" and click "Baseline Processing", then check "General", "Processing" and "Satellites", then check that you have the appropriate settings so that it doesn't ignore the Glonass data.
Under baseline processing, the only settings that would appear to matter with respect to this issue are listed under the sub-heading Satellites, and in my case, all of the GLONASS satellites are checked, just like the GPS satellites. The elevation mask is 10 degrees.
You're on to something here, Loyal. I looked at the sp3 files imported into the project, and they appear to be only for the 31 GPS satellites. I will look further into this. Thank you!
Which module do you have? Survey Standard or Survey Advanced?
Loyal,
I'm a bit confused on how to select the appropriate sp3 file on this FTP site you provided a link to.
I made my observations between 2pm and 5pm (local time, eastern standard time) on 12/17/2012.
Al
I am on my phone, so don't have my "bookmarks", BUT, IIRC, on the US sites, there are no GLONASS orbits EXCEPT for the final ones, if you want something quicker, you need to get them from one of the other observation centers (Euorpe and maybe Canada). Can you just use the broadcast orbits in TBC? I know in LGO (Leica) you can select to use the broadcast orbits only, this would test Loyal's theory.
SHG
Al
Well....I think this will do it (or not).
ftp://cddis.gsfc.nasa.gov/glonass/products/1719/
Download igv17192_00.sp3.Z and unzip it.
Shelby knows a LOT more about this GLONASS stuff than I do, so hopefully he can set us straight about the oribits.
The IGS Site only indicates "FINAL" orbits for GLONASS as Shelby says.
Maybe all of that 99999.... stuff is intended to disable the use of the orbit data for those birds (sometimes it shows up on the GPS birds too).
Like I said before, this GLONASS stuff is above my pay grade.
Loyal
Clock Offsets
I had to go back and look at the sp3 file format info (it's been a while).
The "999999.999999" in spaces 48-60 indicate missing (or invalid) clock offsets. This would preclude any attempt to process the GLONASS data (I think). Time permitting, I will look at an IGS FINAL GLONASS file and get back to you.
Of course that isn't going to help you in the short term.
Loyal
I've gotta look that up. I don't know offhand for sure. I'm not at my computer now (skiing). Thanks!
> Which module do you have? Survey Standard or Survey Advanced?
David,
At the License Manager (Help>About) Survey Advanced and Survey Standard are both listed as Status "Enabled". So I'd say I have "Survey Advanced".
Al
> I am on my phone, so don't have my "bookmarks", BUT, IIRC, on the US sites, there are no GLONASS orbits EXCEPT for the final ones, if you want something quicker, you need to get them from one of the other observation centers (Euorpe and maybe Canada). Can you just use the broadcast orbits in TBC? I know in LGO (Leica) you can select to use the broadcast orbits only, this would test Loyal's theory.
>
> SHG
Shelby, thanks for your help.
I used a pair of Topcon Hiper Pro receivers to collect 15 second static data during this 10 minute window. I would have gladly rather done it using RTK but I was surprised to be out of range of the base radio at just over 2000 (wooded and hilly) feet.
I downloaded the TPS file (Topcon format), and used Topcon Link to produce RINEX files, including the .yyG, .yyN, and .yyO files. I understand that the .yyG format is the GLONASS broadcast ephemeris file in RINEX format.
Trimble Business Center will allow me to import both the .yyN and .yyO files, but upon attempting to import the .yyG files, it fails, stating "Cannot open file". I don't understand why that is the case. It doesn't give any further information in the error message.
Al
Is GLONASS processing maybe an extra cost option? Just thinking that TBC might be rejecting the GLONASS because you don't have GLONASS enabled?
SHG
Nope, I've got the advanced version of TBC, and it includes processing of GLONASS data.
Al
> Well....I think this will do it (or not).
>
> ftp://cddis.gsfc.nasa.gov/glonass/products/1719/
>
> Download igv17192_00.sp3.Z and unzip it.
>
> Shelby knows a LOT more about this GLONASS stuff than I do, so hopefully he can set us straight about the oribits.
>
> The IGS Site only indicates "FINAL" orbits for GLONASS as Shelby says.
>
> Maybe all of that 99999.... stuff is intended to disable the use of the orbit data for those birds (sometimes it shows up on the GPS birds too).
>
> Like I said before, this GLONASS stuff is above my pay grade.
>
> Loyal
Loyal,
I'm slow at this. Thanks again for your help.
I downloaded the file you linked to, and was able to extract it, and was successful in importing it to Trimble Business Center. Trimble recognizes the ephemeris as a precise ephemeris, and acknowledges that it includes both GPS and GLONASS satellite systems.
And, the SP3 file that I imported covers a 48 hour period beginning on 12/17 0hr to 12/18 24 hr, and includes therefore the 10 minute window within which I was observing data with my receivers. And, the SP3 file includes the PG and PR satellites.
After re-processing the baselines, the results are virtually identical.
And, now I understand the part about the 999999.999999 values for the clock offsets. Yes, it looks like this SP3 file has 999999 values for all the PR satellites, but legitimate clock offsets for the PG satellites.
So, looks like I might have to wait for the final GLONASS ephemeris to be published by IGS.
Al
