Hello, we are having problems reaching a steady fix between our stationary base (RS+) and the roamer (M2) which is placed onboard a robot.
In terms of the base station, we do not have problems with the base receiving an RTK/RTS FIX. We have trialed both stationary and kinematic settings and observed no difference. The problems seems to be the roamer itself or communication between the base and the roamer. The roamer receives connections via LoRa at 928Mhz. We test in large open spaces so interference from trees and building should have no effect. People may walk past but not sure that should change anything. The antenna is elevated above the robot, the roamer is away from onboard electronics and we see between 28-30+ satellites at all times. Both systems are also up to date.
The following are the cases we might get:
The signal switches between FIX and FLOAT every few seconds continuously. Only way we have found to overcome this is to turn the robot off and back on.
The signal remains in FLOAT for over 20 minutes. Might converge after this time but generally we don’t wait for this long and restart the robot.
Works perfectly and converges nearly immediately or up to 5 minutes.
The problem cases (1 and 2) occur more than 50% of the time and turning the robot off and on again we might experience a different case even though nothing has changed.
We have tried different interference testing:
The computer onboard the robot hosts a website at 2.4GHz on our phones so we thought - this could potentially be interfering. We tried different phone positions but this had no affect.
Standing right next to the base vs. keeping clear to determine if interference from us.
Changing the base to static. No change in getting a FIX
Are there any other suggestions to achieve a more consistent FIX?
RS+ is a single-band receiver, while M2 is a multi-frequency receiver. You can’t use RS+ as the base for your M2 because it sends only L1 corrections, which is probably why you can’t get a stable FIX with this setup.
You can use the M2 as the base and the RS+ as the rover. However, this setup doesn’t offer the advantages of working with multi-band receivers. Further, you would need to consider how to set up the M2 as the base, which can be tricky.
Hello @ruth.bongon,
I just want to add to my original post that it is the M2/M+ LoRa radio as the roamer - not just the M2.
This makes a lot of sense thank you! What emlid setup would you suggest so we can take advantage of the multi frequencies and faster fix? We are open to other emlid devices.
Yes we will have the same set up: M2/M+ and antenna will be placed onboard the robot as the rover with a stationary base.
I followed these instructions switching the two emlid devices around: Base and rover setup | Reach RS/RS+
I also included NTRIP to the new base which is not apart of these instructions. The new base (M2/M+) connected to NTRIP and got a FIX and the new rover (RS+) started to recieve corrections but never reached a solid fix. Are there some more instructions for setting up the M2/M+ as the base?
In terms of a replacement we are definitely open to other EMLID devices. If the M2/M+ is successful we might choose this as the new base due to price but any other base suggestions?
Fixing-performance is a lot better on multi-frequency, with the M2.
Single frequency (M+) is very picky about baseline distance and receiver environment in general (sky view, multipath conditions etc).
In my opinion, just buy one more M2 to pair with your base station M2, and you’ll see great performance.
It should work the same way as the other Reach models, although I agree with @wizprod. M+ is a single-band receiver, which is usually sensitive to obstructions and baseline distance.
Please 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.
Since the data contains sensitive information, you can send it to us at support@emlid.com. Thanks!
Hello,
I’ve realised a mistake I’ve made! The original roamer is an M+ with an M2/M+ LoRa radio and a Tallysman GNSS antenna and not an M2. So the original set up was this as the roamer with the RS+ as the base. Either way this set up had inconsistent results as mentioned in my first post no matter the ideal conditions and the multiple tests we tried.
So would multiband be the way to go? And is the best set up the 2 M2’s as base and roamer?
Sorry for the confusion!
A couple things you could do if the M+ (rover) and RS+ (base) are not satisfying your needs. In a open field without tall buildings and trees right up against you should still work fine in my opinion even for a single band receiver. May be something else or settings. You can email support@emlid.com your full system reports to see if they can help.
What are your rough coordinates to see your environment and/or photos around the test site.
For most economical route using Emlid multi-band receivers instead of single band:
You could buy 1 M2 (and use the existing external LoRa you already have with it), Multi-band helical GNSS antenna and use as rover.
I agree with @timd1971. Single-band receivers should still work fine under good conditions. If you work in an open field but struggle to achieve a stable fix, we need to check the data and your settings. Please record logs for the base and the rover for at least 15 minutes and send them to us along with the Full System Report. We’ll investigate it.
I’ve shared the links on how to do it in my previous reply. Thanks!
I just want to update you all that we found the root of the issue. It seems like QZSS sats are making the solution unstable. After disabling this constellation, @kathrine.wiki20 could finally achieve a stable FIX, even with a single-frequency base and rover setup.
If anyone encounters the same issue, please feel free to contact us via email at support@emlid.com.
