Poor Performance of radios LoRa in Rs3

Hi.

I bought a pair of Rs3 antennas last year and have been frustrating to use in Rtk mode.

Connected through ntrip or LoRa.

Before buying the Rs3 I had some Rs from 2018, which by the way continue to work without a problem even though they no longer receive updates.
I thought that by having the Rs3 the improvement would be in all aspects but that is not the case.
The fix I get with the Rs3 is very unstable, it jumps from fix to single all the time. It becomes annoying.

A couple of weeks ago I did a stakeout in a semi-arid area. Few trees of 3 or 4 meters. Use an Rs3 as a base, another Rs3 as a rover and as a precaution carry an Rs due to the poor LoRa experience on the Rs3.
The stakeout points were about 300 meters away.
At the end of the day I finished the staking with the 2018 Rs because the Rs3 no longer received corrections and remained in single mode.

Which makes me wonder… Did EMLID modify or reduce the capacity of the LoRa radios in the Rs3 to introduce the UHF receiver they now have?

What can I do to improve or increase the LoRa connection? I see that Emlid now sells an antenna to receive UHF corrections in the Rs3.
That antenna connects to the same port as the LoRa antenna? If true, could you use it to send and receive corrections with LoRa?.

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In the meantime, email full system report to support@emlid.com

Screen shot your Lora and RTK settings on both units to see if something wrong.

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The UHF antenna is tuned for 410-470 MHz which is a completely different frequency band to LORA 900 Mhz and would not work properly.

LORA is low power at only 0.1W and very line of sight. If you are amongst trees, buildings or over hills the signal will get blocked and reduce range. Thats just the basic physics. I get a few hundred meters in the bush here with LORA and I’m happy with that given what it is.

A UHF radio will work bit better in difficult conditions at the lower frequency, and push out more power with some up to a max of 35W but they require a licence. Horses for courses.

EMLID don’t (yet?) have repeater capability but it is possible to get an aftermarket longer range LORA antenna kit but I haven’t tried one so can’t vouch for it.

There are some tips here that include tweaking the frequency and lowering the air data rate that may help extend the range: How to configure LoRa for RTK on Reach RS2+ - Support tips - Emlid Community Forum
And it’s even possible your RS2/3’s are simply configured differently.

Otherwise you could use Base Shift in Flow to get the base closer and/or higher up overlooking where you are working.

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Hi.

I have never understood users who defend the negative or problems of a product and even less those who mention that since it is a low-priced product we have to hope that it does not work properly.
Do you imagine that Emlid will place a warning on his page? “Our products are low cost for the same reason they may have problems getting the job done.”

I know you didn’t mention the price but it is one of the many excuses that several Emlid users have.

Personally I am not satisfied with such a range. And I am not requesting more than what they promise in the characteristics, not even half 4 km. But a reasonable range that allows me to work without problems.

I asked Emlid about the uhf antenna because I had the “hope” that if it used the same SMA connection port as the LoRa, it would be longer and, I suppose made of better material than the stock antennas, it would be able to work with it.
I had already noticed the difference in frequencies but I want to be sure.

I don’t know if you have or have worked with Rs3 but I can tell you that the fix and connection between them is very unstable.
I mention again that by using Rs3 as a base and as a rover’s an Rs3 and a Rs from 2018.
I get a greater range and more stability in the fix with the Rs.

I appreciate the idea of ​​buying a LoRa antenna with a longer range, I suppose it could be a solution.
I don’t know if anyone can recommend any brand or dbi’s with which they achieve good performance.

Greetings.

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Something is either different with your settings between the old RS and new RS3 or a hardware problem with the RS3 (or even firmware etc problem?)

I don’t think that anyone is defending excuses… but its pretty common to say “you get what you pay for”. I.e. plunk down a HUGE amount of cash (or hock your home) for a full Leica or Trimble setup that already HAS HIGH POWER RADIOS for your needs and instant support when you need it… but that is going to cost you… on a constant basis $$$$$$$$$$$

Leica and Trimble can do this as goverment agencies DEMAND their use for huge million/billion dollar projects.

There are options for higher power radios, which u can search here. But honestly, it may just be your settings or possibly something wrong with the hardware worst case scenario. Email support@emlid.com and upload screenshots.

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No-one is defending anything, simply pointing out basic physics and its limitations that apply to anything. And actually spending time trying to help you including steps you could take, have you looked at the configs?

Yes, I have two RS3’s and I use them the same as you. And I also have Trimble receivers. They all add value, and I Iike all of them. And LoRa is one of the things I particularly like about the RS3’s, you don’t get 900mHz and it’s simplicity with Trimble survey receivers. It’s typically only found in their construction & agriculture systems for use across local sites because of it’s limited range. There’s a message there.

You are not providing much detail to help anyone to help you if you do really want it.

Some general possibilities:

  • Environment, you haven’t provided any details/pictures including obstacles. Are you actually testing the RS against RS3 at the same reference points so it’s apples to apples or is it just a general opinion? If you have tested then it would help if you post the details.

  • Check the base and rover LoRa configurations, they should be the same.

  • Tune the LoRa settings for maximum range, e.g. different frequencies & air data rate.

If I understand right and you are not changing the RS3 base when you switch rovers to RS (?) then maybe you have a Rover reception issue and there are some specific things you could look at:

  • If the RS works and RS3 doesn’t then try configuring the RS3 same as the RS was if it was different.

  • Possible RS3 Rover antenna problem. Do a simple test, e.g. swap antenna with the base and see if the RS still works ok.

  • Possible Rover receiver issue, ditto above but needs RS3’s reconfigured between Base/Rover. Does anything now change?

  • Send all the details to Emlid Support.

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If you post these , maybe we can see whats going on

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Hi @erro.alfaro88,

It’s indeed curious why your Reach RS performs better than the Reach RS3. I can confirm that we didn’t reduce the capacity of LoRa. The UHF antenna can be connected to the same port as the LoRa antenna, but they still work differently. The UHF antenna is only useful for the rover because the Reach RS3 is only capable of receiving the correction over UHF radio. For the base side, it requires an external UHF radio. You can learn more about this in this thread.

But back to your Lora issue, the guys above have already shared some pretty good tips to find the source of the issue, but here you can see the full checklist:

  • Check that the receivers are placed in the line of sight.
  • Mount the receivers on a survey pole or tripod of at least 1.8 m high to ensure they have a clear sky view.
  • Use the settings from the Base and rover setup guide to set up your units.
  • Ensure that the LoRa antennas are firmly attached.
  • Try to tune the radio by changing the radio frequency in the available range.

You can find more details about each step in this post from our community forum.

If it doesn’t help, please do the following test:

  1. Bring the receivers to a place with a clear sky view. You can follow the recommendations from this guide.
  2. Configure the units as the base and the rover according to the Base and rover setup guide.
  3. Enable the Raw data debug option on both receivers.
  4. Record the logs on the units for at least 10-15 minutes. We will need raw data logs in UBX format from both receivers, correction log in RTCM3 format from the rover, and position log in LLH format from the rover.
  5. Generate full system reports and send all the data to me at support@emlid.com.

It will help me check what is going on with the receivers in detail.

Thank you!

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Hi @zoltan.biber

I’ll definitely send an email.

Yesterday during a stakeout job the Rs3 rover once again performed very poorly.
Let me explain the chronology.

I have attached a screenshot of the work.

Place my Rs3 in “Base” with known coordinates.
First point to stakeout with Rs3 rover. number 3 with a distance of 233 meters. I managed to place it with difficulty.
I tried to stake out points 4 and 5 at a distance of 358 meters and I did not get a solution, single mode on the rover.
After a while and several attempts I decided to change Base Rs3 to point 3.
I try again to restate points 4 and 5, I don’t get any correction, single mode. Only 134-135 meters since new Base (Point 3).
Once again I have to take out my reach rs from 2018, I get a fix solution in a few minutes.

I decide to finish the work with the Rs 2018, I did not miss any corrections from the base Rs3.
Even so, I kept Rs3 rover on and got fix before reaching point 1. A very unstable fix (it goes from Fix to single all the time) that becomes annoying and embarrassing with my clients.

I share the configuration used in the Rs3 and Rs. From inside my house.

Base rs3. Imu, bluetooth, mobil data and position output 1-2 are off



Rover rs3. Imu, bluetooth, mobil data and position output 1-2 are off.
I have set the update frequency to 5hz and 10hz and I get the same performance



Rover Rs




I share the requested antenna data and complete reports to support@emlid.com

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Seems like something hardware-wise may be wrong on the RS3 ROVER? Since RS3 BASE and old RS work?

Wonder if the LoRa antenna wire inside RS3 ROVER is disconnected Or faulty or some other internal issue? Even L1 L2 antenna wire disconnected or faulty? Dont open as to void warranty and Emlid may not help. Let them exhaust options before that of last resort.

Maybe swap the RS3 BASE with RS3 ROVER to see if ROVER works with old RS?

I guess could try different frequecies too if RS3 ROVER works after that test? Settings seem ok. Upload screenshots of the MESSAGES settings also.

Otherwise, see what Emlid figures out.

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Hi Tim.

Unfortunately, changing their position is not the solution. It was the first thing I tried.
Initially when I received my pair of RS3s my base antenna was the rover and my rover antenna was my base, but to the malfunction i decided to change the position.

Another thing I see is that my rs had the “fix and hold” option enabled, I don’t know if the rs3 are working in “continuous” mode, I understand that since the rs2 the fix and hold and continuous option is already disabled to choose manually.

I share the rtcm messages that are activated on base. although they are the values ​​that came from the factory, I have not modified them.

I hope the Emlid team tests their equipment in the field and not just in the office.
As additional information, I confirm that the problem only occurs when the rs3 is in rover mode.

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Hopefully Emlid helps you out and hopefully your RS3s are still under warranty.

If it isn’t the Stop and Go setting or something else, maybe it’s hardware issue. I.e. faulty LoRa, connectors etc.

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I got your files via email, Erro. Thank you for it and for their screenshots! Let’s continue the discussion via email, and once we finish the investigation, we can share the result here as well.

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Hi Zoltan.

I want to know why the rs3 fix is ​​very weak?.
It seems that they are programmed to work in “continuous” mode as I had written and not in “fix and hold” mode.

Another thing I don’t understand and that I assume is the main part of the problem is why the rs3 is programmed to jump from fix to single mode without going through float once it loses the fix state, that does a “reset” on the antenna.

This programming of simulating an automatic “circuit cut” does not make sense since it cuts all communication with the base (LoRa radio).

In the Rs when you lose fix you maintain float in most situations and you know that there is still communication between base and rover and you maintain a certain precision.
that does not happen with the RS3, when you lose fix it simulates a “reset or circuit cut” and it is more difficult to recover the fix when you are far from the base antenna.
There are even times that you lose fix and the antenna shows the message “no solution” as if it were turned on inside a house and there was no satellite on view.

I have been doing tests and I would the tittle of the post to Fix very unstable and difficult to recover in Rs3.
As I explained, when I use Rs3 as a base and Rs as rover I maintain a constant fix.
I think the problema could be in the way the Rs3 is programmed.
Continuous Mode and an automátic restart (circuit cut) when the fix is lost, wich makes it more difficult to recover a solution when the antenna is far away.
When the antennas are close there is no problem.

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Hey Erro,
I share your frustration.
I have been experiencing similar results that seem to be getting worse & worse.
Today I dedicated my entire day to troubleshooting and I am no closer to a solution.
The LoRa radios continue to be a source of contention and the weak link in the Emlid RTK architecture.
I have owned 3 x RS2 receivers, 1 x RS2+ and 2 x M2 receivers so I have a clear idea of how these machines work.
At present, I cannot achieve a Fix beyond 100m baseline - with a clear line of sight and clear view of sky.
I have already exhausted the problem with Tech Support via email and they have not been any help.
The set up I am using is a RS2 & RS2+ as Base & Rover respectively.

When I started using these 2 receivers I was getting an optimal range of up to 1 km in very sketchy circumstances. Over time the range has just gotten worse & worse and now it is at an all time low.

Switching them around has not improved the range. Changing the radio parameters has not improved anything. Today, I even tried using them without the OEM LoRa antennas 1 at a time to see if perhaps one of them had a busted antenna connection. The range reduced to 10m so I guess that is not the problem.

I have tried aftermarket antennas, that seemed to improve, but not for long.

There is only 1 thing left to try and that is to re-flash the firmware on the Base receiver (I already flashed Firmware on the Rover last week).

I will try that tomorrow and hope it works.

I will be posting the results here.

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Curious.

You have 2 M2s.

Do you also have 2 LoRa radios for them?

If so… do you have these same issues with those? Good thing though if external LoRa radios fail over time, can always get new ones for M2s.

Very odd… you used to get 1km in rough conditions now down to 100m in ideal conditions??? :woozy_face:

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Wonder if the LoRa components including the Power Amplifier are degrading/failing over time of long use?

But that would not explain the case for new RS3 units unless using lower grade components but would assume the same as before?

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Hey Tim
I bought the M2s to make a base station (which i still haven’t done) and also to be used as a back up field system if needs be.
I have a single LoRa radio.
I have tested these systems but they are not in every day use.
I made reference to them simply to point out that i have a functional knowledge of the Emlid RTK receivers.
In my testing, the M2s worked well.
I have not used them in some time as the circuitry for the Metta housing that I bought to be used with the M2 went bad.
I agree with you- very odd results.
My last experience with Emlid customer service was disheartening since I was made to feel that because the conditions were not perfect, (there were power lines & trees visible in the photos I sent) then these could have been at least partially responsible for the poor range. The site had clear line of sight and clear of the sky. I don’t see how any real world situation could be better than that. I was not able to achieve a 70m fix that day

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I have considered that as a possibility.
I have also noted that I am no longer able to connect my mobile devices on Emlid Flow via bluetooth
Also, the Emlid Flow wifi connection “disappears” after some time.
In order to reconnect, you have to restart the receivers.
Very odd behavior

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I’d use the M2 (and if u have an antenna to connect to it though?) with external LoRa Radio to test and systematically rule out between equipment.

Very odd as you used to get 1km, but now hardly that in comparison.

I agree, high voltage power lines etc will cause interference… but sounds like that response about it was unreasonable.

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