Inaccurate GPS

lauriepurcell said:

i am finding the GPS accuracy is very poor...

Very strange indeed, I find it to be spot on.
Had the Forerunner 245 before and the 955 is way more accurate and consistent.

lauriepurcell said:

i run the same track regularly

I also have one track, I run quite often and in different conditions (rainy, sunny, different seasons). It is in a forest on a road, so some issues with the trees to be expected, especially when they have full leaves and it is rainy.

Google Maps says, this track is 10,3 km long.
FR 245 gave me 10,32 most times, with a „bandwidth“ of 10,28 to 10,37 which I find really acceptable.

FR 955 also gives me 10,32 most times, with a bandwidth from 10,30 to 10,34 (but really seldom).

Settings I have nearly the same, BUT have GPS set to autoselect („SatIQ“) for running activity.

Maybe a stupid question, but do you wait every time for the GPS fix (green confirmation) before starting the run?

For me it's very accurate, spot on...

But pretty much impossible to say anything without concrete examples, some connect activities for example. Also, what how different are the different distance, what kind of area are you in, lots of high buildings? Forests? Etc?

So many factors and so little information

hi

yes i make sure the "green circle" is active before all runs... 

i wonder if the weather contributes to the inaccuracies

at my 5k point, i get 4.8k or 5.2k rarely 5k

lauriepurcell said:

i wonder if the weather contributes to the inaccuracies

Yes, it does. Rainy conditions dampen the signal from the satellites, especially when the rain is becoming very dense.
If you are running under trees with leaves it is not optimal generally, but gets even worse when the leaves are wet, this also affects the dampening.

micchei said:

Some meters difference is ok for a GPS.

Yes, generally. BUT

lauriepurcell said:

at my 5k point, i get 4.8k or 5.2k rarely 5k

This is 4% difference and this is quite a lot. I never experienced more than 1% difference, most of the time less then 0,5% - even with the Forerunner 245. And the FR 955 has better, more accurate GPS.

I think, there must be another error.

4% difference is generally not ok, even considering the limits of GNSS.

lauriepurcell

One thing to check:

- Do you run with an external HR Monitor, maybe the Garmin HRM Pro (Plus)? If yes, check the settings (under settings - sensors). The HRM Pro has a movement sensor and it CAN be used for calculating the pace and distance... but this should be set to "only indoors"!!! It absolutely makes no sense to use it for distance outdoors, as it is way less accurate then the GPS of the watch.
But we had some folks in the forums, that checked the settings and confirmed, it was (accidentially) set to "always" - so the GPS was not used, but instead the movement sensor of the HRM Pro was used to calculate the distance - which could explain your relatively big difference

Thank you for your help, everyone!

In addition to those tips, I'd recommending reviewing GPS Drift and Environmental Factor Impact on GPS Accuracy. 

I also suggest changing your data recording to Every Second: Smart Recording vs. Every Second Recording on Garmin Devices

It can also help to sync with your Connect app before your activity if possible.

I hope this helps!

hi thanks for your reply... however overall it doesnt explain why my 920xt NEVER had these problems ???i had hoped a newer model would not experience such inaccuracies... i also use an external garmin hrm pro not plus...

Maybe try setting GPS recording to ‘every second’ and and not ‘smart recording’ and give it a go? I don’t know what your 920xt did but this is a function which trades file size, battery life and GPS accuracy. I have most of the same settings as you on my 955s (but with every second recoding) and the GPS tracks have been consistently pretty flawless! 

The tip about syncing with your phone is to ensure the GPS ephemeris (etc.) data on the watch is up-to-date. But that mostly affects how quickly you get a GPS fix, not its accuracy.

Hi, i'm a kayaker.

I'm also experiencing GPS problems with my Forerunner 955 in kayaking and other water sports which obviously impacts me a lot. The tracks are irregular, and speed readings are very wobbly, which makes it very hard to use. I never had these problems in my Forerunner 935.

I've tried updating the watch, setting it to 1-second recording, changed the GPS settings and none of it worked. So, I reached out to Garmin support and followed their recommendations. However, the issue persisted.

When I contacted Garmin support again, they dismissed the issue as "regular behavior" and mentioned that the watch's precision can range from 3 to 15 meters depending on the environment. I don’t understand how something not experienced with older watches can be considered "regular behavior" and what role the environment has in my problem, since the activities I complained were mostly recorded in a clear open sky.

Seems like garmin products are out of question for anyone interested in watersports.

Needless to say, I will never buy another Garmin product. I'm very disappointed with this watch and local Garmin support. It has been like this for over a year, and there's been no fix. For what’s supposed to be the best GPS tracking ever in Garmin watches, it is simply unusable for basic speed tracking.