"The Natural Philosopher" wrote in message
...
If you have GPS on so you don't have to wait 5 mins until it has
worked out where it is.

If you have quickfix enabled they take a few seconds even from cold.

What's quickfix? Sounds intriguing.


GPS tends to be accurate to about 5m or less these days.
They usually have at least 12 channel receivers so they can get good
accuracy if they can see enough sky.

My Android phone (Samsung Galaxy S2) takes a very variable length of time to
get a fix. I have an app called GPS Status installed which shows the number
of satellites in view and indicates whether or not they are supplying
information that enables a fix to be calculated. It also downloads S-GPS
information from the internet (assuming there is mobile/wifi coverage) which
helps to give a quicker fix - I think it supplies the "almanack" information
which is only transmitted from the satellites every few minutes.

But even with this I can find that from cold it can take from a couple of
seconds to tens of minutes to get a fix - usually if I get fed up of
waiting, a reboot of the phone will help.

And GPS Status shows a maximum of about 10 satellites out in the open,
whereas some newer phones can see many more, and I'm sure this allows them
to get a quicker fix and/or to give a more accurate location. The best
precision is reported to be about 10 m, and usually it is more like 20-50 m.

It may be time to get a newer phone, both to give a faster processor and a
better GPS.

I'd keep GPS and wifi or mobile internet turned on all the time, but both
drain the battery: even with them turned off, I'm lucky if the battery will
last all day. If I'm going anywhere that wifi or GPS are essential (eg
tracking a long walk) I use a large external battery that keeps the phone
charged. It doesn't help that I live in a weak mobile phone area so my phone
winds its gain up to maximum to search for a mobile phone signal to check
for incoming calls/texts: if I spend the day in a large town, the battery
lasts a *lots* longer than if I'm at home, all other things being the same;
the only difference seems to be mobile signal strength, as reported on the
phone's Settings | Battery graph.