Can someone give real world situation as how well the LORA radio works in normal surveying situations. in practical working areas we have you normally do not have line of sight, and most tell what max range is but they are using line of sight.
Hi Joe
My experiences seem to be way below the performance others have been enjoying.
Most of my terrain is hilly and well forested.
A few weeks ago, I managed to get a 500 metre shot, no trees, but a small hill (perhaps 3-6 metres?) in between base & rover. Tried venturing 100 metres to another point (along the same 500 m radius) and lost fix due to broken radio transmission.
This has been the peak of my radio range thus far.
Usually I will lose fix at 200-300m.
Hi Joe,
Welcome to our community 
LoRa radio performance highly depends on the environmental conditions, so the maximum baseline varies from one area to another. It’s hard to predict the exact value without local tests. Usually, it’s up to 8 km, but some of our users reached 40 km and 50 km baselines with the built-in LoRa.
If there’s commonly no line of sight between the base and rover in your sites, it can affect the signal transmission badly. In this case, you can try out other options - connect the units via our free Emlid NTRIP Caster or a pair of external radios.
1 Like
40-50km with LoRa and no modifications? That is very hard to believe that they could maintain +/- 0.10ft at those distances. It’s also hard to believe you can maintain a fix for that matter unless you are on a mountain with CLOS to everything. Our typical cutoff point is about 3000ft which is just over a 1/4 mile. That said we do have some rolling hills and cedar trees are very dense but even on farmland we don’t get more than 5,000ft.
1 Like
As I remember the experiment, it wasn’t about accuracy, but about the reach of LoRa.
For me, to get repeatable RTK results, one shouldn’t exceed 20-25 km.
4 Likes
Hi guys,
These tests show that the LoRa radio range can be pushed much further than 8 km in some conditions. Still, the obtained coordinates’ accuracy depends on various factors - thanks for pointing this out! For instance, it’s the accuracy of the base placement, the baseline value, and correction link stability.
4 Likes
Yup, the run was pure test of LoRa range and beating @Luke_Wijnberg s range 
Also demonstrating the power of 0,1watt radio and what you can accomplish if its used right.
And yes, I did use the stock LoRa setup with RS2. But the base was placed at 280ish asl, thus having line of sight over the entire island. I had to place base high up according to the fresnel zone
Not sure how useful the RTK link would have been, just a tiny radio blockage would break the FIXed solution.
Which brings me to another statement, what is the accuracy for RS2 in RTK and 60km baseline?
With the dual band and a static rover, I think its doable. I have done it before but without VRS and buggy firmware without stakeout options.
I am willing to test this, now that I have access to VRS and can run a double verification.
3 Likes
Doing week long obs of 30 second averages, you will see differences from high to low of 20 cm or more with a 50 km baseline.
To get repeatable 2-3 cm, you need a baseline of 20 km or so. All given ideal, or close to ideal conditions for both base and rover.
VRS can save you some effort, but if you are within 15 km, some say that normal RTK is preferable.
VRS will suffer if there are large elevation changes between rover and the VRS network bases.
1 Like
20cm? thats alot.
Well, i dont have time for week long observation, way up in the mountains
What do you reckon my numbers will be if I did a random 5-15min static at 66km baseline?
Yep… so if you just measure with 1 hour in between, you might be within a few cm, but if you return a week or days later, you could see up to 20 cm of difference with a 50 km baseline.
Atmospheric interference is simply hard to model at that distance.
1 Like
Indeed. At the moment it looks allright thoug
https://sesolstorm.kartverket.no/
But did you analyze it further?
If you log long enough, there will always be some error in the dataset. E.g 1 year logging.
I mean, we are talking odds and % of beeing right (or wrong)
I tried logging the stddev for thousands of 30-second measurements over different baselines. There’s a clear exponential tendency.
50-60 km baseline will give you 7-9 cm of stddev in the vertical component.
I think this is a very intersting field. Its something many fail to take into consideration creating points or survey. How the range affects accuary and the magnitude of error it produce.
I might extend this 66km test for 2 or 3 more session over the next month and I can show the numbers.
1 Like
We see this practically in machine control. Our operators are responsible for checking in to one of the permanent monuments we setup before lunch every day. Weather conditions sway the numbers obviously especially when there are drastic temperature changes. In the machine there is a “Hold-Down” setting which they can adjust at 0.01ft increments until their readout matches the BM. It’s not uncommon to hear about +/- 0.15ft change across days and mind you that this is with static base points and only 2500ft baselines.
Line of sight only mate, similar situation as the gent early on, short range but a tiny mound in the middle and it would drop out, I’m lucky to get 1200m
I’ve got a Lora antenna on the way to try and improve it but there’s an Aussie surveyor with a repeater kit on the market for about $1200aud that we’ll likely get because it’s pretty disappointing, I got buggered over this whole week because of the lack of range
2 Likes
Thanks for the input Cameron.
Would you be kind enough to post a link for the antenna? I’ve bought one but it was the wrong connector type.
Also post a link for the repeater please
I agree with this: if you can, go with the NTRIP service. It is more reliable, and works in all conditions (where cell service or internet access exists).
LoRa is a well-known frequency that does not bounce off the atmosphere or earth, and therefore requires very good line-of-sight to work reliably.
@TB_RTK is absolutely correct about paying attention to the Fresnel Zone, which Surveyors often overlook…
3 Likes
FYI
3 Likes
Just adding my informal note here which confirms what others have said. I have had a good fix (2-3cm) using LoRa with true line-of-sight out to easily 30 kilometer range, and that was with the rover stuck out of a vehicle window, moving at 60 mph (95 km / hour). But as others have noted, even the smallest blockage to line-of-site (such as a very low hill or sometimes a building) will block the LoRa connection.
I also find that I have more reliable results, generally, using CORS / NTRIP over cellular data connection. And it’s way more convenient (where available) because there’s no base setup to do, no worries about security or battery life of the base, and no need to return to the base unit to collect it at the end of the survey.
5 Likes