(GPS) Performance Testing: Florence

The small streets of Florence, run with a Coros Apex, Polar Vantage V, Suunto 9 Baro, and Garmin Instinct – it really puts GPS to the test.

It is always nice to run past Florence’s beautiful cathedral of Santa Maria del Fiore. But, what is really interesting are the contrasting conditions, between the tight urban canyons of the old town and the wide curves on the hills above.

The Setup

This time, I had a chance for two runs in Florence and used all watches in GPS + GLONASS mode. With the limited view to the sky, it should be – and generally is – necessary to use GLONASS to even just get a position fix.

It isn’t necessarily a good one, though…



In the map above, I also included the gpx of the route as I had created it, using the “Follow Roads Walking” option. It is interesting to see that this feature sometimes doesn’t actually follow paths as they are marked in other map views or simply visible.

Automatic Non-Paths

One case in point: At Piazza della Signoria, the automatically created route follows the facade of the Palazzo Vecchio, creating a “hook” one certainly wouldn’t follow.

Florence, Piazza della Signoria - with the route automatically "following roads" along the facade of Palazzo Vecchio
Florence, Piazza della Signoria – with the route automatically “following roads” along the facade of Palazzo Vecchio
... and the satellite view
… and the satellite view, which makes it even more obvious that the auto-route also goes over houses at the (western) edge of the square

In the map view, but better still in the satellite image, it also becomes noticeable that the automatically created route follows the edge of the square – or even jumps over houses.

Certainly not the way a human would run there; it’s not even a place/path one can go…

Wrong Side!

Another case which would also make it difficult to determine track accuracy versus a route (if one wanted to compare those to calculate it) came on the hills above the city.

The view from that road is great, both down to the old town and up to the sky – and for the GPS devices, to satellite signals.

Automatically "followed" route on the wrong side of the road
Nice footpath north of the road. Visibly marked on the map – but the “follow roads walking” has one walk in the middle of the road and then south of it…

The supposed route, as created from the map data used by the automatic “follow roads walking” feature, ends up on the wrong side of the road, though. The path, meanwhile, is where I ran…


What to say…?

It is pretty obvious that the Garmin Instinct had some serious issues here. And those regularly. It had worked considerably better in the mountains…

All in all, the tracks recorded here are a beautiful example of the major importance an open (or not-open) view to the sky has.

"Meandering" up to Piazzale Michelangelo
“Meandering” up to Piazzale Michelangelo

The “meanders” up to Piazzale Michelangelo, for example, were very well recorded by all the watches. Here, the view to GPS satellites is also pretty open – and had already been quite open before getting there, running along the river.

These results are hardly worth mentioning; certainly, they should not come as a surprise. But, it’s exactly these matters of course which we tend to overlook.

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