Emlid Reach Problem Retaining Fix

GPS / RTK / GNSS
1

Finally started using AgOpenGPS earlier this year with Emlid Reach modules (original 1st generation single band ones).
Base module connected to an antenna mounted on the roof of my house. It is logged into an account with RTK2Go, sending NTRIP correction data over wifi to my 4g mobile router (only usable broadband connection in my locality- no fibre, and ADSL is useless).
Rover module is connected to GPS antenna mounted on the roof of my tractor cab. Powered by and sending position data via USB to a Windows 10 tablet. Smartphone provides a mobile WiFi hotspot which reach rover uses to obtain RTK correction from RTK2Go.
Rover usually obtains a fix within a few of minutes of being powered up, and whilst it maintains a fix, combined with the AgOpenGPS software provides a top rate guidance system. I am only using it as a lightbar at present- I intend to put tilt compensation and autosteering in place some time in the future.
Sadly though on occassions, the rover loses fix, and drops to float with very much poorer accuracy. Having moved to float condition, usually (but not always) it is unable to restore a fix without rebooting the module.

Any suggestions on why fix is being lost?

Reach modules are running firware version 27, so almost fully up to date.

Generally I have a clear view of the sky- but I am on a North facing slope, so there will be some limitations on the number of satellites visible to the South. My mobile data signal is generally good, so shouldn’t be a problem with loss of connection to the NTRIP caster.

Could the fact I am relying on mobile data for connection to the NTRIP caster by both base and rover be an issue?

Have other user found issues with reliability of RTK2Go?

Would a dedicated mobile router in my tractor provide a more robust Wifi connection to the NTRIP caster than using a smartphone as a wifi hotspot?

If I upgraded the single band Reach module I am using as my rover to a multiband Reach M2, would this retain or regain a better/ quicker fix? Can I use a Reach M2 rover with my single band Reach Base for RTK corrections?- I dont necessarily need the extra accuracy of the multiband, just want an improved fix.

Any suggestions to resolve this issue would be much appreciated.

I do like the fact that the Reach modules connect directly to the NTRIP caster, so not tying up the tablet dealing with processing the correction, but would an alternative GPS receiver maintain a better fix?

2

Are we truly talking first 1st gen Reach? the little circuit board ones?

or RS+/M+? are a ublox M8N
They take forever to fix, they do not take partial obstruction well.

Check that your rover is not in “Static” mode, put it in “Kinematic” mode
Your base should be in static mode, make sure you have averaged in and locked your base position in.

They do take much longer to fix 0-3min.

RS2/M2 are a ublox F9P

You would need to upgrade both base and rover to take advantage of dual band. RS2/M2/F9P fix very fast especially after warmed up. You would also need new dual band antennas as well.

I use a M2 as base because I find it easier to setup and PPP in that role, I use an evaluation board for rover because it is a bit cheaper. Ardusimple F9P or Sparkfun SMA F9P are good choices.

3

Sadly I wasted my money on those early single band emlid units. Mine only ever achieved a fix maybe 25% of the time. I tried lots of things they recommended but to no avail. Some people seemed to have luck with them but not me. I don’t think they’d ever work for a tractor.

4

Yes, it is the original circuit board Reach units I am using. Upgrading to the latest firmware appears to have improved their performance along the way- but they still do permanently loose fix- maybe 3 or 4 times over the course of a day, requiring a reboot to get going again.
I am pretty sure I have the settings as you have described, but I will check.
Will probably just have to bite the bullet and invest in dual band receivers and antennas if I want to get away from this issue.

5

The F9P/M2/RS2 dual band units are great, they are worth upgrading too for sure. No complaints yet they just seem to work.