Garmin Position Enhancement – now live and tested on Fenix 8

The capabilities of the Garmin Fenix 8 may appear superficially unchanged. Still, the GPS firmware has been upgraded to an entirely new version, with newly added support for the Beidou and QZSS regional satellite constellations. A new feature that enhances positional accuracy has also been introduced. This suggests that Garmin may have quietly added a modestly upgraded GNSS chipset, though based on my knowledge of component suppliers, I’m unsure which one it might be. Maybe it’s a firmware bump enabled by a new antennae design?

I never observed it correctly using dual frequency in my previous, extensive testing of Garmin’s original Dual Frequency, Multi-constellation chipset (the one with SatIQ). Let me explain: the purpose of dual frequency is to determine the signal accuracy from each satellite. Each satellite broadcasts two frequencies; if those signals bounce off a building, they travel different distances. The receiver (the watch) detects these different distances and identifies the information from that satellite as incorrect. It then ignores that satellite, which is fine because dozens of others are likely available to get an excellent positional fix (should be accurate to 50cm). This mechanism should provide the most significant improvement in GPS accuracy for a watch, improvement to a point beyond which further improvements will only ever be in niche use case scenarios.

However, let’s be honest—for the first time, the latest generation of chipsets can be described as accurate (not perfect, but generally accurate). Still, Garmin’s chipsets continue to show “GPS shadows” near tall buildings. What happens is that the recorded track drifts away from the tall building you’re running close to. This is clear evidence that reflected signals are being used, and if reflected signals are in play, as explained earlier, it indicates that the dual frequency system isn’t functioning correctly.

Position Enhancement

[Watch Settings> System> Advanced> Position Enhancement> ON].

Tip: Don’t waste your time trying this feature.

What I initially hoped for with this feature was that the accelerometer would be used to mitigate issues like GPS shadows, but it seems my hope was misplaced.

The feature activates when the GPS track is poor, which, on the surface, sounds promising. It suggests that the GPS chip is assessing the accuracy of each signal, which is exactly what I was hoping for. However, the feature only appears to work when the overall track is significantly wrong.

Additionally, this is an offline feature processed through Garmin Connect. While it might improve the appearance of your GPS track and potentially enhance distance accuracy, it won’t help runners looking for improved instant pace feedback. Nor will it assist when following a route in real-time, although the “snap-to-road” feature might help in that case ([Settings > Map & Navigation > Lock On Road > ON]).

A Test

Using GPS-only, I ran through my local town centre, which has several tall buildings. I recorded multiple tracks with the Fenix 8 and other watches (Garmin FR965, Suunto, and Apple). After the workout, I checked the TCX file downloaded from Connect, and it was identical to the FIT file on the Fenix 8. This leads me to assume the data synced back to the Fenix 8 after being processed and saved on Connect.

The image shown above/below best shows the situation. As you can see the RED track (Fenix 8) is ‘prettier’, smoothed compared to the black tracks (FR965, Suunto RACE). The red track is often significantly further away than my actual position.

Usefulness

I can see how this feature might be useful on very long adventures where GPS recording is set to intermittent intervals, such as once every 60 seconds, to preserve the battery. The accelerometer could help refine the track between each recorded point, making it more accurate and detailed than just a simple straight line.

However:

While one-minute intervals should, in theory, save a lot of battery, recording at that frequency also requires powering up and locking onto GPS signals, which might consume more power than anticipated.

Additionally, the Garmin feature only works for tracks up to 12 hours long, so it’s designed more for correcting inaccuracies than for battery saving. From what I can tell, it introduces some inaccuracies.

But the track is pretty, I’ll give it that. But it’s wrong.