You folks in the gps post-processing and network adjustment business, try out GrafNav/GrafNet if you have a chance. Definitively a top of the line product.
> You folks in the gps post-processing and network adjustment business, try out GrafNav/GrafNet if you have a chance. Definitively a top of the line product.
Georges, you use Trimble receivers, as I recall. How do you go about importing the receiver files into that software without having to manually enter antenna types and heights? I had understood that one feature of the software was that it did not recognize the Trimble antenna types, either in the DAT file or in a RINEX file generated from it. Is this not the case?
> You folks in the gps post-processing and network adjustment business, try out GrafNav/GrafNet if you have a chance. Definitively a top of the line product.
I'm still waiting for an evaluation copy. The sales rep I've been dealing with said he ran out of dongles, but promised one soon. It's been about a week. 🙁
I am working with two methods to import Trimble data in the project.
- Succesfully with RINEX files (created with TGO's utility)
- Unsuccessfully with DAT files (error message "no epochs found")
Antenna types (pull down menu) and heights are entered at import.
> I am working with two methods to import Trimble data in the project.
>
>
- >
- Succesfully with RINEX files (created with TGO's utility)
> Antenna types (pull down menu) and heights are entered at import.
So, if I understand you, then, a Trimble user with stop-and-go data would have to enter the antenna type and height for every occupation? That would be a bit rough for a stop-and-go file with hundreds of points in it.
On the antenna type issue: How does GrafNav/GrafNet handle the 4600LS internal antenna, which I don't think has an NGS calibration? Were you able to create an antenna phase center model using the Trimble model for it?
Kent
As far as the GrafNav/GrafNet antenna calibrations files go, YES...you can pretty easily generate a TRM_4600 antenna type. The files are simple ASCII text (see below), so it is somewhat like editing a Trimble Antenna File.
Ant {
AntID: "TRM4800"
Desc: "Receiver+Internal microcentered antenna"
Source: "NGS"
Numtests: 1
Date: "99/01/12"
HzDist: 0.0
RefPoint: "Antenna Base"
L1Offset: -0.2 1.5 175.9
L2Offset: -0.6 1.3 178.9
NumCorr: 19
Corr01: 0 0.0 0.0
Corr02: 5 0.0 0.0
Corr03: 10 0.9 -0.8
Corr04: 15 2.1 -0.5
Corr05: 20 3.6 0.2
Corr06: 25 5.2 1.1
Corr07: 30 6.6 2.0
Corr08: 35 7.8 2.8
Corr09: 40 8.7 3.4
Corr10: 45 9.1 3.7
Corr11: 50 9.1 3.7
Corr12: 55 8.6 3.5
Corr13: 60 7.7 3.0
Corr14: 65 6.4 2.2
Corr15: 70 4.9 1.4
Corr16: 75 3.4 0.6
Corr17: 80 1.9 0.0
Corr18: 85 0.7 -0.3
Corr19: 90 0.0 0.0
}
The latest NGS ANTINFO file (see below) has ABSOLUTE data for the TRM4800, so you should be able to reverse engineer something that should work fine for your purposes.
TRM4800 NONE L1/enhanced L2 receiver,with internal an NGS ( 1) 11/03/25
0.4 1.1 157.8
0.0 0.5 1.0 1.5 1.7 1.8 1.7 1.5 1.2 0.9
0.6 0.4 0.4 0.6 1.3 2.8 5.4 0.0 0.0
-0.7 0.7 171.3
0.0 -0.4 -0.5 -0.5 -0.4 -0.4 -0.4 -0.7 -1.1 -1.5
-1.9 -2.1 -2.0 -1.7 -1.1 -0.0 2.0 0.0 0.0
The use of the TRM4800 was just for clarity, you will have to relate the 4600 to the 4800 (or something similar) to get the job down.
Loyal
Just for a simple example, kinematic data comes in as two files: base and rover. The antenna heights and definitions only need to be entered at the files check in. Rover Point ID's are also included. This is done in GrafNav.
About the antenna settings, presently, all I am doing is using a generic antenna (no offsets) and I key in the true (I think it is anyway) height from ground to L1 antenna phase center. 3 readings combined. For example with the 4600:
1. From ground to bottom of antenna mount - Varies from station to station
2. From bottom of antenna mount to mechanical phase center (the 107mm value)
3. From mechanical phase center to nominal offset (the 27.6mm "up" value)
I think that's how it works. But this method does not take into account this 5 deg's interval adjustment. Not sure if it makes a big difference in the grand scheme of things. The method of Loyal is probably a better one.
I applied the same logic (generic antenna) with the GNSS Solutions that I could not get to solve properly and solutions are working okay now.
> Just for a simple example, kinematic data comes in as two files: base and rover. The antenna heights and definitions only need to be entered at the files check in. Rover Point ID's are also included. This is done in GrafNav.
Georges, just to be clear, when you check in rover kinematic data, you have to enter the antenna heights for each station in the DAT file or just the antenna type?
I just entered rover kinematic data antenna height and type once, that's at the time that the data is imported in the program. All PPK observations have the same height (2m) in this case. One shot deal.
If you have different PPK data within the same file with different antenna heights, I am not too sure how the software would deal with it. I haven't try this scenario.
> I just entered rover kinematic data antenna height and type once, that's at the time that the data is imported in the program. All PPK observations have the same height (2m) in this case. One shot deal.
>
> If you have different PPK data within the same file with different antenna heights, I am not too sure how the software would deal with it. I haven't try this scenario.
Yes, typically I will have at least two different antenna heights in a kinematic file, which is why I'm interested in how GrafNav/GrafNet handles the antenna height entry. I can, of course, see that simply using a pole fixed at one or the other height would be a workaround to keep from having to manually enter individual heights at hundreds of stations in a segment.