Ideal Settings while Driving ~12km/hr on Bumpy Road?

Hi, we have a setup with an RS2 on a moving ATV and I was curious if there was a better way to set it up. In part because it seems to somewhat regularly lose fix.

These are for electrical conductivity surveys we conduct with an EM38.

  • RS2 rover on back of an ATV
  • RS2 base nearby, typically within a few hundred meters and usually (not always) line of sight
  • Just have local accuracy, don’t care about global
  • RS2 rover is communicating solutions o a laptop via bluetooth. Survey machine, EM38, is also communicating to laptop via bluetooth and it is the laptop program which is taking the GPS results and assigning coordinates to the sensor readings.
  • Terrain is very bumpy, sensor bounces around a fair amount. Driving at about 12km/r
  • Don’t care about being super accurate, being with half a meter is fine. More accurate is better but not necessary.

Given how bumpy it can sometimes lose fix and constantly be losing connection/reconnecting. Because its getting results as a stream, isn’t a critical difference and doesn’t seem to vary too wildly.

Mostly I’m just curious if there are better settings for this kind of more unusual setup for a rover. Thanks!

Could be the bluetooth, but the losing of the fix might be the ATV getting in between the base and rover. I had similar issue when truck mounted and using radio. That went away when I started using the network. Regardless, bumps shouldn’t be making it lose fix. Have you tried Wi-Fi to the rover?

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Hi @intenna,

I might have missed it, but how do you establish the RTK link between the base and the rover?

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The rover is beeping like its losing regaining fix. That is, two quick beeps in fairly quick succession. Or at least that’s what I’ve usually understood those beeps to mean.

I did notice it happening more when a piece of our GPS stand broke and the rover was thus bouncing around a lot more. But that is anecdotal.

How do you mean it went away when you started using the network?

And by WiFi you mean from laptop to rover?

Hi Ruth, I could be missing something obvious here. But I have set up the link for work and when I use it in traditional survey mode (via Emlid Flow) it does get a fix which I assume means the RTK is setup correctly.

Yes, I mean, do you use LoRa or NTRIP to pass corrections to your rover?

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That is an interesting problem. I have used several brands of GNSS gear and have never experienced an issue with vibration or bouncing causing an issue with the connection.

When I started using network service directly to the receiver instead of radio from the base to the rover I haven’t had to worry about those intermittent line of sight fix losses.

That is correct on the Wi-Fi. Your data collection device is networked to the rover. The only really downside to this is that it requires a data connections so sometimes you are forced to use a local base but they have gotten our network in Central Texas pretty solid and I haven’t had to use a base station in a year.

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Lora

Interesting, maybe its time to start playing more with this. I’m up in Canada, and with our work we’re not usually worrying about global accuracy, just need it locally, so haven’t bothered too much with NTRIP and other such solutions. Maybe time to change that.

Hi Bryan,

Thanks for confirming. Could you please try passing the corrections via NTRIP and check how the connection is? For this setup, you can use our free Emlid Caster. Thanks!

In that case you will need to perform a localization so that the grid reference system you are using on the ground can be related to the geodetic coordinates established by your NTRIP provider. The datum as it comes out of design software like CAD likely won’t transform back to geodetic to match the network within tolerance. This happens because the survey of the subject was already localized by the party that set that control and/or the data has been scaled to surface. The localization function does require the Survey subscription and unfortunately you can’t import localizations from other solutions.

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Hi Brian
I am sorry I’m so slow at posting, I only just saw your thread.
We use our RS2 Rtk setup mounted a lot of the time on a vehicle. The majority of the time it is used on a side by side UTV, but also on a Ute and even had a run on a grader. We do a lot of our own survey work for the erosion rehabilitation work we do, among other things.
The bumps and vibrations should not be your problem at all.

I think we have had a similar problem to what you have experienced as well. One site we worked on was insanely bad. It was the second job we used our receivers on too, so I thought it was proving to be a bad purchase (we love them now!!). The beeping of loosing and regaining fix also drove me insane. I initially thought it was too far from the base or blocked by a small mound of dirt. The loss of fix started occasionally and seemed to get worse through out the day to the point it was constantly cycling in and out of fix. I drove back to the base and it continued to do it sitting next to each other. Turning the units off and back on seemed to help but eventually the problem would return. I found the answer for us was to manually change the LoRa frequency on both units and the problem disappeared. I never worked out what was causing it and have since gone back to the default frequency and have had no problems. I suspected electrical interference… couldn’t be from powerlines as the nearest was probably over 10km away, but it may have come from the vehicle.

I really hope this helps you and please don’t hesitate to ask any questions about anything I have said!!

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This is some great insight. While it shouldn’t happen with the way Emlid’s channel selection works vs. other brands it sounds like you were near something that was too close to your channel.

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That’s very helpful, thanks! I am a bit skeptical this is the issue as its happened at numerous sites. But, I could be wrong and all the sites are within about 50km of each other.

So I’ll test this at our next project. Thanks again!