>> iPhone uses AGPS to get started
Any smartphone with GPS will use assisted GPS to start with. You perhaps don't know why.
To figure out where you are the GPS receiver needs to know where the satellites are. This data is called ephemeris data. It can take a bit of time to download this via the GPS satellites. A quicker solution for data enabled devices was to download this ephemeris data via the data network.
So maybe you're not referring to AGPS after all? Maybe you're referring to smartphones' ability to work out roughly where they are (quite accurate at times) using other means including wifi signals and mobile phone masts.
>> whereas on my bike the trace would suddenly jump sideways off into a field or become
>> very spiky maybe it has something to do with me travelling at a far slower speed
If the phone had line of site of the sky (and not trees/foliage) etc. then walking or on a bike is better than in a car to get a good signal I'd have thought.
Last edited by: rtj70 on Tue 4 Jun 13 at 20:01
|
iPhone & GPS new
iPhone & GPS new