Did a ride yesterday and seem to have missed off about a dozen or more segment times. Viewing these, i get a lot of
"
Why it Did Not Match
Your Activity seems to have taken the wrong direction or path near the start of the Segment
"
However it's the Ridgeway, i can't have been more than 4' away. Looking at my segment, it's all over the place, rather than down the paths.
I also recorded it on the Garmin, but i've not uploaded yet to see if that helps, all the Strava data up to now is just Android phone based.
But, i guess the question is, can i improve the Android aspect ?
Hi Weeksy - as you replied on my thread earlier, and the above is relevant - my previous phone was fine and started with the above issues before failing to record anything ... hence the new phone in the other thread !
not use the strava app. I think it only records a position every 4s.
I used to use the wahoo app which records at 1s interval and can submit to strava directly.
make sure the phone has a good sky view, back pocket of jersey or top pocket of bag. If I put my phone in side pocket of shorts or chest pocket the quality degrades massively.
I doubt it, used to have the same with an iPhone which is why I bought a Garmin. Which you already have?!But, i guess the question is, can i improve the Android aspect ?
Suspect its your device not Strava
I'll upload from the Garmin tonight and see what results i get, but i generally just leave it on the handlebars as i only use it for a live HR view.
https://support.strava.com/hc/en-us/articles/216917707-Bad-GPS-Data-What-Why-How
I suspect the Garmin will be more accurate. It's not perfect though. GPS accuracy for civilian use is around 4 or 5 metres and that varies by location, country, and just signal quality (and at times, can be deliberately made worse, bearing in mind GPS is a US Military system 😉 ). Some devices support GLONASS also which is the Russian system, and combined this can improve accuracy. Although in my experience it mainly improves lock on time.
You may find the Garmin will show differences in elevation to Android, especially if it has a barometer in it. GPS altitude data is very poor, so Strava adjust it based on topography data, but that has a resolution limit, so in a square of 50, 100m or whatever, their data may say one altitude, but in fact you could have a steep descent or climb.
Barometers are technically more accurate, but they need regular calibration. Though if you're only interested in elevation gain then it's less of an issue. The actual recorded elevation might be wrong but the gain may be more accurate. Though if the weather changes during the ride then it may upset it 😉
(and at times, can be deliberately made worse, bearing in mind GPS is a US Military system )
it was turned off over 16yrs ago for good.
Good point. Forgot they'd turned it off. Apparently that was in favour of alternate GPS jamming systems instead, so GPS satellites are uncrippled, but if they decide some terrorists need sorting out in your neighbourhood they could zap the area for a period 😉
And with Trump elected who knows what he'll do to it to stop those pesky Mexicans.
If you're using an android phone you can turn off cell tower and wifi location services as on some phones they interfer with the GPS accuracy. Had that problem with my S7.
If you use an Android app... Just make sure you have another GPS app running that samples at a faster rate. I'm 99% certain that Strava will get a location update when the other app gets one.
edit - dont do what acidtest suggests. I suspect his accuracy problem was a Samsung thing, the s7 I test with has another layer of permissions compared to "standard" Android.
I seem to get much more accurate GPS traces using GhostRacer on android vs the Strava app. You can also connect it to Strava so it auto submits runs/rides too. Might be worth a try ?
Cell and wifi location services allow the phone to get a rough location in the absence of a GPS signal. It shouldn't in theory affect Strava which should concentrate on GPS but I don't know if the app ignores other location services.
It can be a problem when looking at a map though to find your location. I got caught by this once when we found an injured kid on a trail and were trying to give directions for an ambulance, but my phone was telling me the triangulated cell tower location, not GPS as it hadn't got a fix yet. Luckily I realised this and someone else had a more accurate location.
Anyway, cell services do help GPS as it becomes Assisted GPS. This lets the phone grab satellite positions faster than it would take to get them from the satellites on acquiring a fix, and thus it makes getting a fix quicker. That's another thing with GPS accuracy. If you have zero mobile signal, you may find it takes a long time to get an accurate fix, plus if the fix is lost it may take similar length to get a fix. Hence the signal wanders off during the ride.
There's an app called tracker booster that continually polls the GPS so position data is always available, but using something that samples more frequently than a strava may be an option. I used to use Google Mytracks which helped a bit.
Some Garmin's can be set to 1 second polling. Default is a smart interval where it increases polling intervals if it thinks it needs it.
Though it could actually introduce spikes. However Strava web site will filter a lot of this out. That itself can sometimes go wrong and straight line things.
The garmin picked up today's ride at swinley pretty well, I've not had a chance to upload yesterdays mirror ride though. But I think its safe to say I'll use the garmin for recording not the phone.
Another issue is a lot of segments on Strava are poorly set up. Created from bad data in the first place, have the start and end points in locations that get mixed up or clock people standing around at trail entrances and exits, are too short or too close to other trails so get poorly matched.
No idea but strava on the phone and my garmin never even agree on the distance never mind the height gain