Inaccurate GPS

I wonder if the type of sport affects the GPS accuracy.

Check that the activity's settings also have GPS set to All+Multi-Band.

I did a run this morning under the cover of trees with damp leaves, and the tracking was good (within the ±3m you expect from GPS).

My phone (in a waist-level pocket on my belly) didn't get anywhere near as good a track.

connect.garmin.com/.../12497782573

Silly questions:

* Original strap?

* Any protective case on the watch?

* Screen protector?

Which version of GPS firmware does your watch have? Mine's on GPS 5.00 (with Software version 16.17).

lauriepurcell said:

i also use an external garmin hrm pro

And have you checked the settings like I suggested?

It might be, that accidentally the HRM Pro movement sensor is used for calculating the distance instead of the watches GPS and that would easily explain 4% difference and also that it is sometimes less and sometimes more than 5 km at your marking.

I used to use a vivoactive3. That had difficulty with that course because of the tree cover and the close-together 90° corners. It normally under-read that as about 4.5km. My 955 consistently reads 5.3km instead.

On a beach run, with a totally unobstructed view of the sky and a course which is a smooth curve, both watches read exactly the same distance.

Good to read it's solved, also... must say the HR Pro does a pretty good job of calculating the distance in that case ;)

In my case I run interval training with (for example) 400m fast 100m rest and ... in those 100m of rest the FR955 is not able to track down my slowing  down pace.

The resulting chart is totally wrong and unusable. Looking at the picture down below, in the real world I almost followed the gray chart, so when fast section ends I sharply slow down my pace. This is not charted.

I don't know if FR955 has some energy saving strategy that should be turned off for a 10k,20k training, or training with speed variation. In this scenario it should push on pace and HR precision instead.

Garmin-Sierra we should expect a miracle from the developers team

Well, this is the last time I did intervals.
Setting Autoselect/SatIQ for running activity. Forerunner 955, FW 16.17 and HRM Pro.

I did timed intervals of around 2 min and slow running pauses of around 1 min. The drastic change of pace is clearly and quite instantly visible.

That's a beautiful chart, we should consider that your variation are much wider.You're moving between 3:30 and 6.

Grumpy from dawn till dusk said:

Setting Autoselect/SatIQ for running activity. Forerunner 955, FW 16.17 and HRM Pro.

Same FW version and settings on my FR955, I'm missing the HRM Pro chest strap though.

Sky in view, almost no trees.

During my activities I play mp3s over bluetooth headphones, I don't know if this drain some computational capacity.

I can't identify a clear reason for this.

FlipStone said:

also... must say the HR Pro does a pretty good job of calculating the distance in that case ;)

YES!

Would have thought it would be more than 4%, more like 10% or so. lauriepurcell must have a very nice and steady running style ;)

7419217 said:

we should consider that your variation are much wider.You're moving between 3:30 and 6

Sure, but also the smaller pace changes are drawn quite nicely.
OK, it was out in the fields with no trees and quite flat.

7419217 said:

I can't identify a clear reason for this

Very strange, I agree.