LORA Distance

Hi! How are you?

I have two RS2 units (firmware stable version 31.8) that I use for surveying, and I’ve noticed a decrease in the range of the LoRa radio. I’ve had these units for about three years, and under similar conditions (even in the same places, on jobs I’ve had to return to a year later), the baseline distance has decreased. Sometimes I can’t exceed 250 meters from the base to the rover, even in acceptable conditions like vineyards.

Normally, I place the base at a height of 2.50 meters and the rover at the same height. I’ve tried different configurations, disabling and enabling messages (including the configuration suggested in the tutorials) and adjusting the air data rate and frequency. The configuration below is the one that is currently giving me the best results.

Any suggestions?

Base


Rover

Thanks !

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This is probably irrelevant, but noticed your antenna heights are different? 2.5m vs 2.934m?

Either way. This seems to be a pattern? Others’ posts about this also with no answer yet. Wonder if the LoRa amplifiers are degrading over a few years?

@erro.alfaro88
@adrian.levy99

If nothing comes about it… maybe these which I guess are not in the Emlid Store for some reason?

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In my old rs+ sometimes the antenna was not fully attach, giving poor lora coverage, and sometimes i forgot to put the antenna at all, and still was able to revice corrections over lora in a 100mts radius.

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Hi ! Yes. The height that i’ve described before is the antenna altittude that I use normally . The screenshot is the last setup used on a vineyard that i have to survey yesterday.

I found out about the Lora extender, but it is not yet available in my country. As soon as it is, I’m going to buy it.

But I really think that is not normal the issue.

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Initially I thought that was it. and on the RS2 the rubber that covers the connector is annoying. but no, it is not because it has been poorly connected.

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LoRa should easily manage 250m baseline IF nothing blocks the signal like obstacles or noise.
The first thing I would do is a range test in an open area where the base is rised, like on top of a building or hill, providing line of site to the rover.
You should range at least 1000m with no issues.
Also, Fresnel zone is real and greatly impact the range of your signals, Fresnel zone - Wikipedia

Even though you made it work before in the same area, the situation might be difference now, more dense vegetation, higher vegetation, new introduced RF noise, different or changed contruction near by etc. In my experience it takes very little to disrubt lora signals when you dont have line of sight to the base.

Way back we did a range test hitting over 50km baseline, for your refrence.

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Hello! Yes, I have achieved a baseline of 2km before, but I haven’t been able to do it again. On an airport runway, with the base at 3m height and the rover at 2.20m. But I haven’t been able to do it again.

When I refer to the baseline being reduced in the same place, it is a field where garlic is grown, with no vegetation taller than about 30cm between the base and the rover, and no constructions either. I mean , “same” condition , a year later I couldnt get away 300m cause it get single.

Honestly, the situation seems quite strange to me. That’s why I’m reaching out to you, I’m sure you might have some solution!

Best regards

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Do I understand correct you have 250m baseline with line of sight to the base and no correction is coming through?

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Exactly, the rover stay in single solution.

Pretty darn clear. Flat, etc.

Something seems out of order.
Do you notice any loss in signal gain if you unscrew the antenna? (If you move close enough to the base)
Try vice verca switching base for rover and rover for base.
Also bump the frequency up to 910, and only enable 1074 at 1hz.

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Maybe start simple… swap the 2 screw on LoRa antennas? Do you have an extra LoRa antenna to test?

Do you have a older RS/RS+ or M+/M2 (with external LoRa radios) to test against?

If its not the settings, or the LoRa antennas, maybe its a bad connection between socket and internal connections… or faulty LoRa / amplifier inside of 1 or the other RS2 units?

Try the default Air Rate of 9.11 kb/s?

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I will try that, both things and comment

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I have another pair of antennas and have tested the new ones. Everything remains the same. It’s as if, due to some invisible configuration, the performance of the LoRa radio has decreased.

Unfortunately, I no longer have my old pair of RS+ antennas.

I have tried different air rates and even different constellation configurations, and the best one is the one shown in the image above.

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: /

Hopefully you and others figure it out… really wonder if there is a lifespan even on LoRa amplifiers and electronics? Maybe someone here work near you can test with their equipment? @agrimgalina

It happens exactly the same. 6 months ago I could have a Lora connection of up to 1km or 1.5km but a few weeks ago the distance has only been reduced to 200m or even less. I have tried a thousand configurations and the result is always the same, at most 200 meters in a straight line and with unobstructed views in the open field. My devices are updated to the latest version and are about 3 years old.
Is there any solution for this problem? Because to have Lora coverage of 200 meters it would be better to work with a total station.

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Hi Lucas,

Welcome to the community forum!

LoRa is a low-power radio that requires no obstructions between the base and the rover for the best performance. The baseline will depend on the conditions of the environment and can decrease significantly if you work in an urban area or if there are trees or buildings between the base and the rover.

I would like to investigate your case better. Please provide some additional information and perform this test with the receivers:

  1. Bring the receivers to a place with a clear sky view. Follow the recommendations in 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 logs in RTCM3 format from the rover, and position logs in LLH format from the rover.
  5. Generate full system reports and send all the data to me.

And please note the Full System Report contains some personal information, so please send it to support@emlid.com.

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