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[done] Tracking based on distance rather than time interval

Posted: Mon Dec 10, 2012 10:38 pm
by CRider
Hi,

This has already been asked/discussed (cf. post "GPS Tracking Frequency") but this is not yet in the list of suggested features.
I'm also a Mountain Biker and the ability to define the tracking frequency by a distance would be a great addition.

PS : I've just bought AlpineQuest and I'm quite happy with it.

Re: Tracking based on distance rather than by time interval

Posted: Tue Dec 11, 2012 10:17 am
by Psyberia-Support
Hi again,
No sorry. As you have read in this other discussion, the tracking frequency is based on both parameters, but the user cannot change them separately right now. I have to be careful to do it in a way that won't add any complexity.

The other thing is that a tracking based on the distance cannot be done precisely if you want to save the battery.
Here is what is done for a time based tracking:
- You turn on the GPS sensor, get a fix, and turn it off;
- t seconds after, you turn it on again to get a new location.
Between the update, the GPS is off and won't use the battery.

On the contrary, for a distance based tracking, you cannot to that. You have to choose between:
- Let the GPS always on, and save locations after a particular distance threshold, which would be precise but battery killer;
- Compute an instant speed in order to deduce the time after which the user should have reach the distance threshold, and turn off the GPS until then. This is fine for the battery but not precise because it stands that the user will keep a constant speed.

This is why using both parameter at the same time is a quite good compromise.
But I'll try to work on that soon.

Best regards

Re: Tracking based on distance rather than by time interval

Posted: Tue Dec 11, 2012 11:01 pm
by CRider
OK I see the reason to have a time based tracking.
AlpineQuest wrote: rate (loc/sec), minimum distance (m)
1, 0
2, 1
5, 2
10, 3
20, 6
40, 12
60, 18
To be sure to understand the relationships you provided, does "5, 2" mean a new location is captured every 5 seconds only if the distance from the previous location is at minimum of 2 meters ?

If that is the case, then the only thing that I'm missing is the ability to change the minimum distance.
I would suggest that when the user select one of the time period (1s, 2s, 5s, ...), the user can :
- reuse or modify the associated minimum distance if it has been modified previously
- reset the associated minimum distance to its default value (respectively 0m, 1m, 2m, ...)

Thanks.

Re: Tracking based on distance rather than by time interval

Posted: Thu Dec 13, 2012 2:16 pm
by CRider
Hi,
Can you please confirm or otherwise explain the relationship between the time and the default distance ?
CRider wrote: To be sure to understand the relationships you provided, does "5, 2" mean a new location is captured every 5 seconds only if the distance from the previous location is at minimum of 2 meters ?
Thanks

Re: Tracking based on distance rather than by time interval

Posted: Sat Dec 15, 2012 11:45 pm
by Psyberia-Support
Hi, sorry,
It actually means that a new location will be recorded after a minimum distance of 2 meters, and not within 5 seconds.
Due to the explanation above, you will never get a location before the 5 seconds, however the 2 meters are an approximation.
Best regards

Re: Tracking based on distance rather than by time interval

Posted: Tue Feb 19, 2013 8:42 pm
by CRider
Hi,
Just to let you know that the new tracking distance feature covers my needs.
Thanks.
Regards.

Re: Tracking based on distance rather than by time interval

Posted: Wed Feb 20, 2013 10:06 pm
by Psyberia-Support
Thanks for the feedback!