1. I want to get the GPS location at ~0.0001 accuracy
You can listen only to GPS provider and discard a location when it doesn't have the minimun accuracy you want:
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 5, myLocationListener); // "myLocationListener" must be an object from a class that implements LocationListener
// "myLocationListener" implementation of LocationListener.onLocationChanged
public void onLocationChanged(Location location)
{
int MIN_ACCURACY = 5; // in metters
if ((!location.hasAccuracy()) || (location.getAccuracy() > MIN_ACCURACY))
{
// discard this location and keep listening to new location readings
}
else
{
// that's a good reading!
// do somethings you want... blah, blah, blah...
// stop updates when you get the location to preserve users' battery.
locationManager.removeUpdates(myLocationListener);
}
}
2. Don't want to use internet; Though GSM/CDMA network is ok
Yes, GPS works totally off-line. Android can make use of internet ONLY to update A-GPS data cache and provide faster reads in cold-start updates.
3. Should be obtained programmatically when the app starts
Then call item locationManager.requestLocationUpdates
on mainActivity's onCreate event.
4. Should be quicker, say within a minute (like iPhone, which probably
works in Airplane mode as well!)
Keep in mind that iPhone works with "high quality hardware". Android can be run on crappy devices. So it'll depend of:
- The device's hardware quality;
- The number of satellites that are visible in the sky at that moment;
- The age of almanac and ephemeris data on gps cache;
- GPS can fail to read satellites because user is inside a building or something.
5. The code should work in most of the devices
What is the oldest Android's API you want it to run?
6. The phone may switch-on/off anytime and travel any distance
I didn't get it. What is your concern about this?
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Update 1:
"...I would like to use Android 4.0 and above..."
I've tested GPS features from Android 2.3 to 5.0 devices. Everything runs pretty fine on all of them.
"...I have observed that 1 geo-coordinates based demo app which was working in other devices, din't work in my LGG3 with Android 5.0. Any idea on that?..."
Did you check GPS permissions on Android settings? (Maybe it's disabled) Or can be a hardware issue? Did you try in another similar device?
"...Suppose the GPS is showing correct location in New York,
I switch off the phone and then switch on after reaching to London,
then will it still show correct location (without internet)?..."
Sounds you're confusing things: reading a GPS location is one thing. Showing that location into a MAP is another different thing!
You don't need to be connected to the internet to do GPS location reading. But, if you want to show that location into a MAP, probably you're gonna need internet (to load map resources, etc.).
If you nedd to stay collecting GPS locations periodically (let's say, from 10 to 10 minutes), then it will be better to use AlarmManager to schedule a timer that will "finger" your app and say "hey, time to make a GPS reading!".
"...Also what is your opinion about the latest Fused API?..."
I've tested it and used it for a while, but I gave it up. It needs that Google Play Services be installed to work (not a problem, most users have it on their devices). But if you need ACCURACY (as I do), it will not work. It uses "fused sensors" (accelerometer, gps, wifi, compass, etc...) to try to get user location with minimum power possibile. Sometimes, it says you're 10 miles away from where you're really is. I couldn't make it work fine to keep the "path" where user has been. But it really saves battery.