Poor GNSS accuracy? [Bug 8]

[Gadwin]

So I got my GPSMAP 67 and noticed immediately, that the accuracy is worse than the GPSMAP 66sr. With the GPSMAP 66sr I have almost always 1.8m accuracy and it is really stable. With the GPSMAP 67 I have very often 3m and even this is not really stable. Sometimes it is 4m, sometimes 2.5m and is really wobbly. But almost never under 2m.

Is it for everybody else also the case?

[GPSrChive]

What are the firmware and GPS software versions?

With firmware 4.70 and GPS software 2.46 most users are reporting indicated accuracy equal to or better than the 66sr.

GNSS Accuracy 5ft

GPSMAP 67 v440 GNSS Accuracy 5ft.png

[Gadwin]

Is the 5ft even stable or just for a short period? I did now again a little walk around my house. My device is fully updated, the CPE.bin file is also updated.

I walked outside my house and turned it on. It locked immediately all the satellites, but just with 9m accuracy, that is already a bumer, because 66sr locked it with 2m or with 1.8m. After some second it went to 3.8m accuracy and stayed there. I put in my jacket and walked for 15min and looked again it was at 3.2m and dropped a bit for 2.8m, but unstable and went back to 3.1m.

On a youtube video I saw the same. Maybe some guys are reporting 1.6m, but how stable is it even? I guess, we found the reason for the lower battery consumption? A bit sad, if it is true.

[Nail]

Spoiler

67vs66sr.jpg

Test inside in front of the window.
CPE current,
Wifi on,
Firmware is current.
In 66sr the satellites move, the bars also jump, the accuracy changes, it was also much better than in the picture. On the other hand, in 67 practically nothing happens. The constellation also looks completely different.
It doesn't look good.

[Gadwin]

That is really bad and sad confirmation. For some reason the altitude number is almost the same. I experienced with the 66sr, that the height number also deviates, if the accuracy is poor.

[Richard1982]

I own a 66sr and a 67 and so I also compared them to see. Looking at the satellite page the accuracy of the 66SR is much higher (1.8m vs 4.8m) BUT as I'm walking along the actual accuracy of the 67 seems the same. I wonder if the lower accuracy displayed is actually just a problem with the displayed number and it's calculation? On mine the constellations look and move the same on both devices.

[Nail]

Spoiler

67vs66sr2.jpg

Outside.

[GPSrChive]

I own a 66sr and a 67 and so I also compared them to see. Looking at the satellite page the accuracy of the 66SR is much higher (1.8m vs 4.8m) BUT as I'm walking along the actual accuracy of the 67 seems the same. I wonder if the lower accuracy displayed is actually just a problem with the displayed number and it's calculation? On mine the constellations look and move the same on both devices.

I suspect you are correct. New GNSS chipset will require some refinement, same as any other.

Remember, this is 'Estimated Accuracy', not actual accuracy. No GPSr knows the actual positional error.

[JungleJim]

Didn't do any extensive outdoor tests yet, but in a couple of short walks in the neighbourhood I noticed accuracy going down to 2.1m, with clear view to the sky and no tall buildings around. The tracklog seems pretty accurate though when viewed in GPXSee (Recording Method set to Automatic and interval to Most Often).

[Gadwin]

Sounds really not good, I hope Garmin will improve it very soon.