The GPS accuracy of sports watches is always a cause for discussions – as is the case with the Garmin fenix 6X! We take a closer look at this topic!
Our tests are based on track recordings of outdoor tours. If you are primarily interested in sports such as running, you can also find informations at dcrainmaker.com or the5krunner.com.
GPS reception and sports watches
It is not easy for GPS sports watches to receive GPS signals, many factors can lead to weak signals and thus to significant position deviations. From our point of view, the following factors play an important role:
• A sports watch attached to the wrist is located on a dynamic system, the arm.
• The arm is usually moving, the GPS antenna – on the Garmin fenix the bezel is the GPS antenna – points more or less outwards and not – as it would be best – upwards.
• The sports watch or antenna is shaded by the body.
In addition, there is the less energy available to the GPS receiver ("small case, small battery"), the antenna design, the GPS chip, the software algorithms … all factors that need to be taken into account and pose major challenges for hardware and software developers (recommended reading: "Portables: The challenge of low power and good GNSS performance", whitepaper by u-blox).
How do we test the GPS accuracy of the fenix 6X?
Our first test leads along a track with all kinds of "GPS challenges": from dense forest to a deep valley to rock faces. The round was run twice under the following conditions.
"GPS + GLONASS" was selected as GNSS on all devices. The Garmin fenix 6X default setting is "GPS + GLONASS" and should lead to the best results. Other manufacturers think the same. Polar also relies on the combination "GPS + GLONASS" (the global availability and reliability of GLONASS is even said to be the best of the three GNSS GPS, GALILEO, GLONASS, read Vantage M / Vantage V GPS-Settings). Suunto recommends for its sports watches: "… in difficult terrain, such as a dense forest, canyons or cities with high buildings to achieve better GPS recording results, it may be helpful to turn on additional satellite navigation systems such as GLONASS or Galileo, …". (read: How can GPS recordings be more accurate).
The "smart" recording mode has been selected for our review. This results in less data than in "1s" mode. Recordings are less detailed. However, this setting is perfectly sufficient for the tests (see also: Settings that Improve the Distance and Speed Accuracy of the fenix 6 Series).
For the Garmin GPSMAP 64sx handheld GPS used as a reference, the setting "auto, normal" was selected, for the Xiaomi Mi 9 smartphone – equipped with a dual-band GPS receiver – we selected the mode "every 10 m or every 10s" in Locus Map Pro.
In addition, on all Garmin devices, the barometric altimeter has been manually calibrated before each lap; auto calibration is turned off. This leads to the even elevation profiles displayed below the map.
First lap of the fenix 6X GPS accuracy review:
• fenix 6X and fenix 5X: left / right wrist.
• GPSMAP 64sx: left shoulder* connected to an external dual feed GPS antenna on an antenna plate. The antenna is located above the body as the plate is mounted on a tripod; optimum GPS reception is guaranteed without any shadowing.
• Xiaomi Mi 9: right shoulder* in a bag.
Second lap of the fenix 6X GPS review:
• fenix 5X: right wrist.
• fenix 6X: mounted on the antenna plate to ensure optimum GPS reception without interference.
• GPSMAP 64sx: left shoulder*.
• Xiaomi Mi 9: right shoulder* in a bag.
*: As "usual" when hiking (but causes some shading of the GPS signals).
Garmin GPSMAP 64sx with external GPS antenna
Garmin fenix 6X on antenna ground plate
In the interactive map the tracks can be viewed and analyzed (under "Tracks" a selection of individual tracks is possible).
The following images show the satellite constellations at the three waypoints of lap 1 and lap 2 shown on the map (screenshots: GPSMAP 64sx). The GPS accuracy displayed by the 64sx is 3 meters throughout, a very good value in outdoor practice!
Recording: * smart, ** auto, normal, *** 10 m or 10 s, **** 1s
Lap 1 (left / right: WP1 / WP2 / WP3)
Lap 2 (left / right: WP1 / WP2 / WP3)
1st Lap – Results – Garmin fenix 6X GPS Accuracy
The GPSMAP 64sx reference unit provides the best performance when used in conjunction with the external antenna. This is particularly evident in the difficult sections (for example, waypoint 3), where the sports watches tend to drift significantly.
The fenix 6X and the fenix 5X deliver a hard head to head run, the 6X can be awarded a minimally better recording quality. The dual-band receiver of the Xiaomi Mi 9 smartphone results in a track recording that hardly needs to hide behind the GPSMAP 64sx track (example waypoint 3).
2nd Lap – Results – Garmin fenix 6X GPS Accuracy
The optimal placement of the fenix 6X results in a track recording that is broadly on par with the GPSMAP 64sx in terms of accuracy. This confirms that the factors mentioned in the article above have a great influence on the reception quality of wearables!
The fenix 5X worn on the wrist cannot keep up with this, of course, but still delivers a respectable result. The Mi 9 Smartphone shows a very good result like before.
Some More Results
3rd Hiking Tour
The fenix 6X Pro delivers a very satisfactory result on the mountain tour – especially in comparison to the handheld device – but shows a few "dropouts" at the points marked with waypoints. The track runs straight ahead, even in places with the best GPS reception (summit area). The firmware developers still have something to do …!
4th Hiking Tour
In comparison to the GPSMAP 66s and the multisport watch Sigma iD.FREE, the fenix 6X delivers a very good result. Deviations are within the "usual" range of 5 to 10 meters for outdoor tours (Note: the fenix 6X recording was accidentally interrupted for a while = straight line).
As before, a convincing result with the fenix 6x (the deviations are within the usual range), the Garmin Venu can not keep up with the fenix.
Conclusion – Garmin fenix 6X GPS Accuracy
Our test shows that wearables like the Garmin fenix 6X Pro are able to deliver extremely good and accurate track recordings that are hard to beat by the best GPS handhelds – under conditions not related to practice, mounted on an antenna plate and located above the body. Wearables are worn on the wrist and therefore have to struggle with a few factors that negatively influence GPS reception.
For outdoor tours, the GPS accuracy offered should be more than sufficient; the deviations of 5 to 10 meters that can usually be observed are quite common even with GPS handheld devices. How much accuracy is needed each user has to decide for himself – a runner has different demands than a hiker!