I think that the original question is relavent to this list. Location.getTime()<http://developer.android.com/reference/android/location/Location.html#getTime%28%29>is an Android API and it is supposed to return the time of the GPS fix in milliseconds; this would lead me to assume that it was accurate to a few milliseconds. That it does not on some devices is something I am interested in knowing.
On Sunday, April 22, 2012 1:19:25 PM UTC+1, lbendlin wrote: > > This has nothing to do with Android. GPS chipset features are OEM > specific. Mobile phones use very cheap GPS chipsets with emphasis on power > saving, not performance. If you need better GPS accuracy then get a 10Hz > receiver. but even these are cheating, most of the time they just do > intrapolation. > > > On Sunday, April 22, 2012 4:15:07 AM UTC-4, StarTraX wrote: > >> I'm trying to get the GPS time for a location using location.getTime on a >> location listener using GPS_PROVIDER in my requestLocationUpdates. I was >> expecting the provided time to be the time from the GPS clock - accurate to >> billionths of a second, but rounded to the millisecond. What I am getting >> depends on the platform, but certainly doesn't seem to be what I'm >> expecting.<br/> >> On SGS 11 - Android 2.3.3, the returned value is always an exact second, >> with the millisecond portion always .000. From my experience with GPSs, it >> seems to me unlikely that every polling of the GPS will occur exactly on >> the whole second interval.<br/> >> On an HTC-A7275 Android 2.3.3 - I'm getting the phone's system time, >> certainly not the GPS time. <br/> >> I confirmed these findingsby messing with the phone's time and examining >> the location time.<br/> >> The time stamps in NMEA sentences on the SGS 11 are provided to 3 >> decimals of a second, but on the HTC, they're all xxx.0. The problem using >> NMEA is that it's really messy getting the date and time and full position >> from MNEA: It is only in the GPGGA sentence that has altitude, but it has >> no date stamp so it get's tricky around midnight UTC.<br/> >> I am looking for precise times - preferably to the millisecond for my >> track logger, so that I can reliably compare tracks from different players. >> Has anyone done any more work on this?<br/> >> >> On Sunday, April 22, 2012 1:19:25 PM UTC+1, lbendlin wrote: > > This has nothing to do with Android. GPS chipset features are OEM > specific. Mobile phones use very cheap GPS chipsets with emphasis on power > saving, not performance. If you need better GPS accuracy then get a 10Hz > receiver. but even these are cheating, most of the time they just do > intrapolation. > > > On Sunday, April 22, 2012 4:15:07 AM UTC-4, StarTraX wrote: > >> I'm trying to get the GPS time for a location using location.getTime on a >> location listener using GPS_PROVIDER in my requestLocationUpdates. I was >> expecting the provided time to be the time from the GPS clock - accurate to >> billionths of a second, but rounded to the millisecond. What I am getting >> depends on the platform, but certainly doesn't seem to be what I'm >> expecting.<br/> >> On SGS 11 - Android 2.3.3, the returned value is always an exact second, >> with the millisecond portion always .000. From my experience with GPSs, it >> seems to me unlikely that every polling of the GPS will occur exactly on >> the whole second interval.<br/> >> On an HTC-A7275 Android 2.3.3 - I'm getting the phone's system time, >> certainly not the GPS time. <br/> >> I confirmed these findingsby messing with the phone's time and examining >> the location time.<br/> >> The time stamps in NMEA sentences on the SGS 11 are provided to 3 >> decimals of a second, but on the HTC, they're all xxx.0. The problem using >> NMEA is that it's really messy getting the date and time and full position >> from MNEA: It is only in the GPGGA sentence that has altitude, but it has >> no date stamp so it get's tricky around midnight UTC.<br/> >> I am looking for precise times - preferably to the millisecond for my >> track logger, so that I can reliably compare tracks from different players. >> Has anyone done any more work on this?<br/> >> >> -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
