There are some foot pods that will outperform GPS.
All current running watches and phone software uses single point calibrations. Now if they curved fit 2 or 3 points....
A GPS unit is useful for assisting dynamically changing routes (e.g. driving) or to track unknown paths (e.g. plotting your hike in snow/darkness). May I ask what you'd need a fine-accuracy GPS unit for during a run?
I mostly find the GPS invaluable in hiking. It can be a great thing to have on the top of a mountain in the winter with low visibility. If you get up to a summit and the weather turns, you can have the watch send you back down the way you came. Nice and safe.
On a longer run they are probably accurate to within 1% which makes practically no difference but you often find on a track that the inaccuracy multiplies on each lap so if you are doing say 1 mile repeats (4 laps) then by the end of the mile you can be 20 metres out.
It's not a biggie because visually you can see if your watch says 0.23, 0.46 etc as you go past the 402m mark you know that you need to up your pace because it's short but having a more precise distance and therefore pace would save a few brain cells when you're trying to concentrate on hitting your paces.
On my older iPhone, the mile counts were reasonably accurate. On the 7, there's a spurious ~2 miles per hour added at all times.
My guess is that the 7's chip updates position much more frequently, so that small inaccuracies (a couple dozen feet west, then a couple dozen feet east on the next update) make it look like I'm sprinting all over the place in random directions at high speed. No idea why Fitbit doesn't smooth it out a little...
Did a six hour, 4.6 mile hike in the Adirondacks and it tracked me at 18 miles (edit: 13, sorry).
If the terrain forced you to take a lot of shorter steps then that explains it. In 6 hours of normal steps you'd expect to walk about 18 miles.
Standing still for a break still makes my mileage go up, and I can see the blue dot on the map in the Fitbit app jitter around a little - a few feet here, a few feet there.
Here's an example of the generated map: https://imgur.com/a/yoqei
(That's a ~5 mile hike in actual mileage - and you can see the issue very clearly between "miles" 4 and 5 on the map, where we likely took a long break, and in the longer distance between the downhill miles as we were moving faster)
With the existing L1 signal the multipath signals overlap each other and its hard to find out which the original signal was.
The newer L5 signal is much shorter, so multipath signals will show up as individual peaks, and the receiver can simply pick the first signal, cause that will be the direct one.
Maybe try telling it that you're biking instead, my guess is they do more smoothing the higher speed they expect.
Chips with L5 should do a lot to clear that up though.
What makes anyone confident in the accuracy of wearable tracking devices? I haven't seen it verified and I wouldn't assume it: Accuracy is expensive, generally speaking, and few consumers will pay for it or even question it - how often have you heard someone mention it?
Or, for example, have you wondered how accurate your simple bathroom scale is? I looked into it a little, wanting to collect accurate health data: IIRC +/- 0.1 kg (~0.2 lbs) is available in <$100 scales, but for real precision you need the $500 scales at your doctor's office. And how consistent is it? I tested mine, a decent one with good reviews, and getting it to report the same weight in immediately consecutive measurements was a challenge; I had to stand on it in just the right way.
Here are a couple articles that found the accuracy of activity trackers wanting. I've seen other articles in places like ZDnet that found the same problems, though based on less rigorous research.
Accuracy of Smartphone Applications and Wearable Devices for Tracking Physical Activity Data in JAMA <https://jamanetwork.com/journals/jama/fullarticle/2108876>
Accuracy Of Fitbit Data Seriously Questioned By New Study <https://www.sporttechie.com/accuracy-of-fitbit-data-seriousl...
(Sorry if this disrupts your confidence in your data!)
I tested our old Nintendo wii (or whatever it's called) balance board and so far it gives the same value every time I step on it. The value was also only 0.2 kg off from the doctors expensive scale.
Yeah, I noticed. Does anyone know how this data is normalized by professional researchers?
“What the plaintiffs’ attorneys call a “study” is biased, baseless, and nothing more than an attempt to extract a payout from Fitbit. It lacks scientific rigor and is the product of flawed methodology. It was paid for by plaintiffs’ lawyers who are suing Fitbit, and was conducted with a consumer-grade electrocardiogram – not a true clinical device, as implied by the plaintiffs’ lawyers. Furthermore, there is no evidence the device used in the purported “study” was tested for accuracy.”
Fitbit’s research team rigorously researched and developed the technology for three years prior to introducing it to market and continues to conduct extensive internal studies to test the features of our products. Fitbit Charge HR is the #1 selling fitness tracker on the market, and is embraced by millions of consumers around the globe.
Consumer Reports independently tested the heart rate accuracy of the Charge HR and Surge after the initial lawsuit was filed in January and gave both products an “excellent” rating. We stand behind our heart-rate monitoring technology and all our products, and continue to believe the plaintiffs’ allegations do not have any merit. We are vigorously defending against these claims, and will resist any attempts by the plaintiffs’ lawyers to leverage a settlement with misleading tactics and false claims of scientific evidence.