LS Base to LS RTK Rover

J

Jeffry Turnmire

New Member
I am using an LS as a base station and broadcasting corrections via UHF to a LS rover.
The Base appears to be hard programmed for a certain antenna height and completely ignores any height I put into it at any point in the process before or after it begins transmitting RTK data.

My workaround so far has been to use only known points for setup, then do a back shot (similar to optical methods) get a "corrected" antenna height and apply that to the rover. (typically with the base on a fully extended monopole at 1.85M and the rover set to a 1.7M height the correction is around 0.01M or ~0.03ft.)

For new job sites this workflow is less than ideal, and a source of error.

Have I uncovered a bug? or is this intended behavior? or am I completely doing it wrong?
 
J

Jeffry Turnmire

New Member
Thanks for the update.

Also, when using the LS as a base, when you click the base status button, it does not really show you much "status" information, just takes you to the normal collect screen and does not even show you where it is broadcasting base coordinates from. It would be helpful to have some sort of information as to the actual status of the base.
 
J

Jeffry Turnmire

New Member
I seem to be one of the only people doing RTK with 2 LS units.
RTK has at least been working since I got the units in June. The past 2 weeks it broke with the new updates.

What ever the update did to the UHF radio, seems to have broken the RTK startup on the LS units. Last week with the previous update I was able to get the correction broadcasting to start occasionally. I usually had to restart the units several times to get corrections to start broadcasting. I called every tech support number, left messages, talked to 1 guy who said he had never even tried RTK with 2 LS units, and received ZERO return calls - thanks live tech support.

I installed the new updates today (OCT-22-2015):
UHF: 3.2.4.17
Power Board: 0.1.10.0
WinCE OS: 7.0.60.2
GeoData: 1.13.1.11020
J-Field: 1.11.5.183
GNSS: 3.6.3.151015

Now... 0.000 KB of corrections get broadcast. I tried every modulation: DBPSK, DQPSK, D8PSK, D16QAM: Made no difference. Tried different channel widths: no difference. Different RTCM 3.0 corrections: no difference.

I have tried it with both units. Tried it with brand new projects, old existing project files: made no difference.

At this point I cannot do the work I need to do with the units. I am completely down GPS wise.

Please HELP!
 
Michael Glutting

Michael Glutting

Member
Hello Jeffry,

Thank you for your post advising that this issue exists in the current J-Field release. As we discussed on the phone just now, our J-Field software development team will work to provide you with a solution to get you back up and running in the next few hours. I will call you to provide detailed instructions at that time.
 
J

Jeffry Turnmire

New Member
More information:
To get the RTK to fail with nearly 100% rate, I will describe the process.
Arrive at a jobsite, turn on the LS unit to be used as the base. Click collect button, change the Job in box 1. to a different job than is currently listed (the jobsite we have just gotten to). Return to the home screen. Click settings to start the RTK base setup. Click through the setup, picking the point that you are occupying. Finish the setup process, return to the home screen. Click on the UHF radio status. Once the radio is ready, the RTK correcting transmit counter never starts counting up. <--- almost 100% of the time we can repeat this.

Jeffry Turnmire said:
I seem to be one of the only people doing RTK with 2 LS units.
RTK has at least been working since I got the units in June. The past 2 weeks it broke with the new updates.

What ever the update did to the UHF radio, seems to have broken the RTK startup on the LS units. Last week with the previous update I was able to get the correction broadcasting to start occasionally. I usually had to restart the units several times to get corrections to start broadcasting. I called every tech support number, left messages, talked to 1 guy who said he had never even tried RTK with 2 LS units, and received ZERO return calls - thanks live tech support.

I installed the new updates today (OCT-22-2015):
UHF: 3.2.4.17
Power Board: 0.1.10.0
WinCE OS: 7.0.60.2
GeoData: 1.13.1.11020
J-Field: 1.11.5.183
GNSS: 3.6.3.151015

Now... 0.000 KB of corrections get broadcast. I tried every modulation: DBPSK, DQPSK, D8PSK, D16QAM: Made no difference. Tried different channel widths: no difference. Different RTCM 3.0 corrections: no difference.

I have tried it with both units. Tried it with brand new projects, old existing project files: made no difference.

At this point I cannot do the work I need to do with the units. I am completely down GPS wise.

Please HELP!
Click to expand...
 
J

Jeffry Turnmire

New Member
Michael Glutting said:
Hello Jeffry,

Thank you for your post advising that this issue exists in the current J-Field release. As we discussed on the phone just now, our J-Field software development team will work to provide you with a solution to get you back up and running in the next few hours. I will call you to provide detailed instructions at that time.
Click to expand...
And... A HUGE THANK YOU VERY much for contacting me quickly!
 
J

Jeffry Turnmire

New Member
After playing with the settings for a month and trying to zero in on what is really causing the RTK system to fail to start broadcasting, I have formulated a new hypothesis about the failure.

Through my testing it seems the failure is related to the RTK correction rate.
If the corrections rate is set to 1 Hz. When you turn the LS unit on, it always works.
If the corrections rate is set to 2 HZ. We fail to start about 50% of the time. About like flipping a coin. Sometimes you get lucky and it fails 3 or more times in a row when booting from off.
If the corrections rate is set to 5 HZ. Good luck getting it to start up. Seems to always fail (my Educated Wild A** Guess would be 80% failure - 20% likely to start up)
Knowing just enough to be dangerous, I am guessing that if you get lucky and it starts up in sync with the GPS time signals, no problem, If not failure.

After starting up at 1HZ I have been unable to change it to a higher correction rate and see that come through to the rover. Seems to stay on 1HZ. Actually even if you start up on 2HZ the rover always says 1hz (yes I tried setting the RTK rate to 2hz on the rover)

Seems to be completely unrelated to the project or point I am trying to occupy with the LS Base as I originally thought.
 
Nate The Surveyor

Nate The Surveyor

Well-Known Member
I plan to buy another LS, so that I have 2 LS's. One is base, broadcasting to a radio, and radio to me. This way, in a sense, I have a repeater. Because the separation between RADIO and BASE can be so much greater. Other advantages would be that I get ALL constellations at the base, and rover. This is my planned upgrade path. After it's all paid for, of course!
N
 
J

Jeffry Turnmire

New Member
Nate The Surveyor said:
I plan to buy another LS, so that I have 2 LS's. One is base, broadcasting to a radio, and radio to me. This way, in a sense, I have a repeater. Because the separation between RADIO and BASE can be so much greater. Other advantages would be that I get ALL constellations at the base, and rover. This is my planned upgrade path. After it's all paid for, of course!
N
Click to expand...
We went with 2 LS units for a few reasons:
1. maximum constellation usage/availability/future proofing
2. We choose to use local base stations as much as possible to keep baseline error PPM as low a factor as possible.
3. Here in East TN the hills usually restrict all the radios from going very far, including cell networks.
I believe your land is a little flatter out there in AR.

Javad still has some work to do on LS to LS RTK. It works, but still has plenty of little things needing attention. Base height is still not fixed. Nothing shows you real base status like where the base is broadcasting from - I had an issue with one of my guys a few days ago, thought he had it set to an onsite point, but nope he was broadcasting corrections for a point 20 miles away. Any correction rates above 1 hz cause problems.

The software just need a little attention for the BASE functionality to catch it up with the ROVER.
 
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