RS+ Stays in Single/Float Despite Receiving Corrections

I have two Reach RS+ units that we use as a base station and rover for an archaeological project. I’ve had issues this year with the rover being stuck on a Float solution, despite receiving corrections from the base over LoRa. Often rebooting the rover would solve the problem, though not always.

Today, the rover had no solution or was single solution for almost the entire work day, despite receiving corrections from the base. Sometimes the rover claimed to have zero to only a few satellites in view; other times there 20+, but still came back with a single solution. What could be causing this issue? The base has manual coordinates entered, and the rover does say that it is receiving corrections. The firmware is updated to 30.2 on both Rs+ units.

I would appreciate help in troubleshooting this.

Do you get the same error close to base?
Are you moving into an area with RF noise of some kind?
Have you checked satellite forecast? The sun might mess up radio and satellite signals randomly on the earth.
If none of the above is the case, try lower the amount of data that is sent. Sometimes I found that LoRa might choke up at the receiver end if the reception is poor or noisy.

Thanks for the this. The proximity of the rover to the base doesn’t affect this issue, and we’re less than 100m from our base station anyway. Today it was wonky again for most of the day - no solution despite corrections, picking up more satellites and having a better solution when the rover was angled instead of level - and then miraculously started working for a good two hour stretch. It could be local RF interference, since most satellites have been having a low SNR, well below 35, yesterday and this morning. We are in an open area with no obstructions. I’ll also try a lower data rate, going below the 9.11 kb/s that’s default.

Allright. Try with only GPS data stream only (at base) and ad more system one by one, and see if that makes a difference.

Hi @tpl124,

Welcome to the community forum!

Let’s check why you might have issues with achieving Fix with your devices.

I can see in the simple system reports that you shared with us over that the receivers have the same LoRa frequency set. Usually, it’s the first thing to check with LoRa.

Further on, I would suggest going through the steps that @TB_RTK mentioned above:

  • Make sure there is a line of sight between the receivers, no obstacles.
  • Try setting up different frequencies: one frequency may be occupied which is why the transition through it can be complicated. You can try changing the frequency within the 5-10 MHz step.
  • Try lowering the air data rate. This will prolong the baseline. However, you will need to lower the amount of RTCM3 messages being sent.

If the issue remains, we’ll need to take a look at the following info recorded during the survey:

You can share them with us through This data will help me to see the overall raw data quality of both devices, how the solution status changed through the survey, if the corrections are received correctly, and so on.

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