Getting sometimes a FLOAT solution, can't understand why


We use Emlid Reach RS2 as a base station in mobile scanning, UAV scanning and sonar missions.
Sometimes I get a FLOAT solution when calculating the exact location of Reach RS2 with Emlid Studio.
Usually I use the closest Finnish LeiCa SmartNet station as a reference.

The standard deviation etc of the solution is always good, whether it’s FIX or FLOAT solution.
And in POSPac everything goes well.

So I would almost think it’s a bug, as I have no idea why it’s sometimes FLOAT instead of fixed solution. We always set the base up on open location with good satellite visibility.

Here is the download link for RS2 and ref data from yesterday: Vitomittaus Oy - Download files

Calculated RS location also as an attachment.
REACH_2_CALCULATED.pos (878 Bytes)

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Hi Heikki,

I definitely want to take a closer look at your data. Thank you for sharing it. Once I check it, I’ll get back to you with my thoughts.

Great, thanks!

Hi Heikki,

I’ve checked the data from you. With default settings, I got 100% Float only as well. Then, I set Integer ambiguity resolution for GLONASS as Fix and hold and chose the Combined filter type. And it did the trick – I achieved 100% Fix.

Here is the POS file with the results of static processing in Emlid Studio:
Processing_results.pos (1.0 KB)


Great, thanks! I have to say I’ve totally missed that there is a Fix and Hold -option for GLONASS too :grinning:
But yes, it is there, and I got the same results now.

Not a significant difference between older FLOAT and new FIX solution in north/east, but more than 35 mm in height, that’s already something, of course depending the user case.

This data was actually for a sonar mission trajectory calculation, so not a big deal in the bottom of the sea. But for example if doing mobile scanning, 35 mm is a lot on hard surfaces of road environment.

Hi @hakkilhe,

Oh, just thought that I can add a quick note here.

Agree with you that it depends on the project. Sometimes even the gap of dozens of centimeters doesn’t matter. But the thing with the Float is that you never know this difference for sure. It may be a couple of centimeters, as in your case. But usually, it’s sub-meter. That’s why I’d still recommend relying on a Fix only.

2 posts were split to a new topic: Only Float solution after PPK