Well when tracking location eg every 5sec, what technique should use?

using google maps detect location html5 code - better first detect on high accuracy falling back (if unavailable) to low accuracy…

well when tracking location eg every 5sec, what technique should use?

I’m not sure but note that most phone location apis serve location data the opposite way – you get a very quick response with low accuracy and increasingly slower, more accurate responses as the gps lock in starts doing it’s thing.