GARMIN FR945 - GPS accuracy

GPS ACCURACY

In this section, I provide an assessment of the new Garmin FR945 GPS accuracy. As most of you already know, Garmin changed its chipset provider - to Sony - for all models introduced on 2019. This issue has been a concern for Garmin consumers as most of you know the accuracy issues found in Polar and Suunto devices using the same Sony GPS chipset. For all the runs under analysis, I use the Garmin FR945 with the GPS+GLONASS option enabled and I always make sure the watch acquires GPS signal before the beginning of each run.

I begin the analysis, checking the GPS route logged by the FR945 on a 10K race in Lisbon. This race - Corrida de Santo António - has its 10K distance certified by the Portuguese Athletics Federation.

Run A - 10km race certified distance (Lisbon)

First, let me show an overall view of this course in blue. This race takes place in Lisbon with a section of the course in between a lot (but not that tall) of buildings and another section by the river with fewer buildings.

By the end of this 10K race, the FR945 proved to be extremely precise showing a total distance of 10'090m which turns into less than a 1% deviation. During the race, the 1K auto lap beeps anticipated the official course markers by no more than 100m and the beeps from my watch were more precise than the auto lap beeps coming from other guys' watches I heard during the race (kudos to Garmin!).

Next, I break the 10K race into smaller segments and trace the FR945 segment route against Google maps. 

In the first segment of the race, when I was running in the area with lots of buildings the FR945 had some issues finding the road - it puts me running across buildings like a true juggernaut :)  - you can see the deviation of the blue line from the red line I traced in google maps (where the road is!).

In the second segment of the race, the FR945 again had some trouble in logging my course on the road and shows me running across or flying over some buildings. As I progress to the road near the river with less buidings the FR945 picks up the correct location of my run.

The final segment of the course, as I continue running near the Tagus river, in a place with less buildings the FR945 does not have many issues in correctly mapping my run.

So essentially, on average, the FR945 had an impressive precision, but it's not all sunshine and rainbows - the watch showed some minor deviations especially in the segments with more buildings.

In my second run I go towards the fields and I add my old Garmin FR225 to make a comparison between both devices. I used the FR225 on my right wrist and the FR945 on my left wrist.

Run B - 2K countryside run

This is the overall picture of where I went for a 2K run. The blue line is the FR945, the red line is the FR225.

Overall

In the first segment of the run, the FR945 did very well, and was on top of where I ran. On the other hand, the FR225 had some minor issues as sometimes puts me running by the tree line.

In the second segment of this course, both devices decided to cut the corners on the roundabout. Nonetheless, the FR945 only misses the road by a few inches while the FR225 cuts the roundabout almost in half.

 The final segment of the course looks similar for both devices.

By the end of the race, the FR945 showed a total distance of 2017m at 5:11 min/km while the FR225 showed a total distance of 1999m at 5:14 min/km. The difference turns out to be less than 1% between devices and I am inclined to say that the FR945 was much closer from the course I really took while running.

Ultimately, the FR945 seems pretty solid when using GPS+GLONASS. This is a first-impressions analysis and I will add more tests regarding the FR945 GPS accuracy (and more) in the near future.