My app works fine if the area has GPS (such as outside) or in houses/first or second floor buildings but it does not receive a location update if the area is something like the 4th-10th floor of a tall building, is this expected behavior or is this a limitation of location services?
Even with an internet connection on a high floor it still does not receive an update, this makes me believe that it is not falling back to Wi-Fi/mobile networks but I tried setting my Location method to Wi-Fi/Mobile only in the Android settings but it still works in normal environments.
Can anyone give me advice on what is happening? Do location services simply not work at higher altitudes or certain areas with very poor reception? I have not tested it in underground parking areas though.
I am using PRIORITY_HIGH_ACCURACY as my priority.
I am using PRIORITY_HIGH_ACCURACY as my priority.
That's the reason you are not getting Location change inside a building. Because HIGH_ACCURACY gets location from GPS provider. As we know GPS doesn't work well inside houses as it collects location from satellite.
You can try out other options.
PRIORITY_BALANCED_POWER_ACCURACY (About 100 meter)
PRIORITY_LOW_POWER (About 10km)
PRIORITY_NO_POWER (Act as a passive listener )
You may visit here if you havn't yet. Hope this helps.
Related
I'm creating an app which tracks the location through FusedLocationProviderApi in a Foreground Service.
When I create LocationRequest with PRIORITY_BALANCED_POWER_ACCURACY and start listening for location updates, to my surprise GPS fires up ( Location in the phone settings is set to High Accuracy). I get the location almost immediately (through wifi/cell sources I guess), but as I'm indoors I can't get a GPS fix and it just keeps on trying without end...
Even though I didn't ask for PRIORITY_HIGH_ACCURACY I get hit with significant battery drain and get blamed for using GPS for several minutes.
Is there a way to set a timeout for GPS search (detect indoors situation)?
Is it possible to get a decent location using FusedLocationProviderApi without automatically triggering GPS or do I have to revert to the old location API?
Do I have to resort to limiting each LocationRequest to couple of minutes (setExpirationDuration) and create a new one to prevent the GPS battery drain?
[EDIT]: I think I might have found an another culprit. On a map tab in the app I have set setMyLocationEnabled(true), and this seems to be causing the GPS to flare up. I will experiment a bit more and post the results. Still I'm interested in how the location manager decides that enough is enough when it comes to GPS fix attempt.
Thanks in advance!
Our application uses Google Fused location API to receive location updates every 3 minutes.
The location request settings are as follows –
Interval – 3min
Fastest interval – 1 min
Priority - PRIORITY_BALANCED_POWER_ACCURACY
In a normal running scenario, the location updates are received properly and the location accuracy is pretty good (around 20-25 m).
When the Maps application is opened, it received GPS location, and therefore our application also starts receiving location updates, which are basically from the GPS transceiver (I know this as the subsequent location updates have a speed and altitude value as well).
Problem occurs when the Maps application is now closed. Our application receives location updates, but the location coordinates do not change and every subsequent update received has a higher accuracy value. The updates may go up to even 1000m of accuracy and no accurate location are received. Opening the maps application again will make our application receive accurate and updated locations once again.
This problem can also be device specific as I saw this problem on a Motorola Moto G and not on my other Samsung or Karbonn phones.
In my experience, setting the priority to PRIORITY_BALANCED_POWER_ACCURACY never gets positions from the GPS, unless other app is using it. That's the same behaviour that you are finding in your app (in your case you only get GPS positioning when Maps is open), and that seems to be the general behaviour (see Does PRIORITY_BALANCED_POWER_ACCURACY exclude the GPS provider?).
I haven't found any official documentation to background this so I think that it may be device-dependant. In my tests, whenever I need GPS positioning I need to change the priority to PRIORITY_HIGH_ACCURACY.
Anyway, there is a known issue (57707) that is showing in some devices that causes the location provider to stop receiving position updates when set in PRIORITY_BALANCED_POWER_ACCURACY until the device is restarted.
I have referred many questions on this topic, but it seems some of my requirements are missing:
I want to get the GPS location at ~0.0001 accuracy
Don't want to use internet; Though GSM/CDMA network is ok
Should be obtained programmatically when the app starts
Should be quicker, say within a minute (like iPhone, which probably works in Airplane mode as well!)
The code should work in most of the devices
The phone may switch-on/off anytime and travel any distance
Is there any way to get just the co-ordinates with above mentioned requirements? Any sample code snippet will be much appreciated.
Checking various apps like "Locate Me", "Maverick", which claim to show offline locations. But in various scenarios without internet, they don't give track the location (in India).
I have referred plenty of old/new questions inside/outside SO. Below are few:
Is it possible to have the gps location while offline with the nexus
7?
Does GPS require
Internet?
How to get current exact location in android without internet
connection?
[Note: I am asking this question on behalf of my Android team and will be happy to clarify the details if asked for. Should you feel that this post belongs to Android.Stackexchange, then kindly move it.]
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.
Suggestion is to use Google Location Services
It takes the best possible and accurate location as accurate as it can at current moment. It automatically (with configuration of course) takes best current accuracy too - whatever is available GPS, network, internet, GSM/CDMA/LTE... It also cashes last known location so, basically, you know it every moment - the best what you can.
Of course you have to realize that each service provides its own accuracy and in it's own time. Look, for example, GPS Test App on Android and see how accuracy increases with time and used satellites.
Also Location Services is good for you because it simply provides coordinates - just as you asked and hides a lot of work to determine what real service to use based on time and accuracy. However, of course, if none of the services on your particular device and location can give you required accuracy then there is no way to get it. That's why services also provide accuracy measurement.
Here is another link
Use fused location API provided by Android SDK.Implement fused location in a Service and call it in your application MainActivity.
I have a Service implementing LocationListener listening for both GPS and Network.
The application is dependant on a constant location-feed, but it seems when GPS has a hard time getting a locationfix network location doesnt step in.
manager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000 * 30,0, LocationReporterService.this);
manager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 1000 * 60 * 2,0, LocationReporterService.this);
Questions
How do I make sure that I always get a location?
How can I make sure that if I dont get a GPS-location, I get a Network-location?
Is it a known bug?
Should I have 2 services, GPSLocationService and NetworkLocationsService?
Is there a solution to this? :)
I agree with most of comments from AlexBottoni good answer, although in some points I can't suppot him.
Overview
First, just to check that you are doing it right...
You setup the same LocationListener for both providers. To indentify from where you are reciving the location you need to test it like this:
public void onLocationChanged(Location fix) {
if(fix.getProvider().equals(LocationManager.GPS_PROVIDER)){
//here Gps
} else if(fix.getProvider().equals(LocationManager.NETWORK_PROVIDER)){
//here Network
}
Also, you setup a different acquisition frequency. Gps is providing a new location every 30 seconds and Network every 2 minutes.
As you didn't impose a minimum distance, you should receive a new Location from each one of the providers (as long as they can get a fix) with the frequency requested. If you don't receive a fix, is because they weren't able to acquire one.
Also, it may takes a little longer then requested to get the fix (mainly with Gps), because it may take some time to shyncronize with satellites and fix a location.
Fallback
There is no builted-in fallback from one provider to the other. They are independet, as said by Alex. I'm using the following approach to implement fallback:
Register Gps listener and start a timer
On every GPS location, restart timer
If timer reachs end, register Network listener (Gps listener keeps registered)
If new Gps location arrives, unregister Network listener, restart timer
Preferable Provider
Although Gps may not be available everyhere, is far most precise then Network. In my town, I get 6 meters accuracy with GPS and 1 Km with Network :-(
Two services
Doesn't matter where you register the listener, activity or service, separate ot together, as long as you request them and the provider can get a fix, you will get the location (assuming no bugs in application :-))
Final Notes
Ensure you have the permissions need (ACCESS_FINE_LOCATION, INTERNET, etc).
Ensure that phone setup have Network Location enabled (usually default is disable)
Most Gps receivers support updating information about satellite location, which improves fix time. You can use GPS Satus from the market, to do it.
Regards.
This is really weird because, AFAIK, Android does not fall back to the second choice (network location provider) only if and when the first one (GPS) does not work. The two location providers are indipendent and should be sending location updates to you listeners indipendently to each other. Hence, the first one (GPS) should not be able to block the second one (network) in any case.
Regarding your questions:
How do I make sure that I always get a location?
You don't. There is no way to be sure. There are cases in which you cannot get any location fix just because no location reference is available. This is often the case in metro/underground stations. No GPS, no cellular antennas (not everybody lives in NYC or London...), no wi-fi hotspots so no way to determine your current position. Believe it or not, in the new hospital of my town, we have this situation at the moment because GPS constellation is not visible (indoor...), no wi-fi hotspots have been installed yet and the only available CellID antenna is just a few hundred meters away so you get the same signal everywhere, both outside and inside the building.
How can I make sure that if I dont get a GPS-location, I get a Network-location?
You cannot, either. It depends on the available networks. Anyway, you can check what you get from the location providers in your code and switch from one to the next until you get a usable location fix.
Is it a known bug?
No, it is not a bug. It is more a known limit of the existing technology.
Should I have 2 services, GPSLocationService and NetworkLocationsService?
It is something to try. As nick already said, this should not be a problem but a check should not hurt.
Is there a solution to this? :)
If your app is intended to be used mainly in a urban environment (a town), most likely you should use the network location engine as your main location engine. Nowadays, every village and town is covered by a large set on cellular phone antennas and by a large set of wi-fi hotspot so you are more likely to get a good location fix from the network location provider than from the GPS one. This is particularly true in towns with high buildings and narrow roads (that does not just mean NYC. Even here in Venice we have problems with the GPS). The network engine is also faster in getting a first fix and works indoor as well.
Fall back to GPS only if and when the network location engine does not work.
I am using GPS to fetch location at 15 second interval in my android application. It is giving correct data but sometimes it fetches forward location and after that again fetches backward location. In result i am getting wrong track on google map.
Please help.
Your question is a little big vague...
The problem with GPS is that it is highly dependent on your whereabouts. Things such as tall buildings and sometimes even large trees can have a major impact on your GPS readings. Being inside a structure or outside is also another major factor which must be considered. Also, most of the time, the GPS will return different GPS co-ordinates even if you stay in the same place.
The average margin of error of a GPS usually varies between 5 and 50m. When you say 'forward' and 'backward' location, I am assuming that you mean that the GPS is returning a value for a position which is either ahead of you or behind you.
The fact that, as you say, the GPS most of the time works, leads me to suspect that the issue you are experiencing varies depending on your actual physical location, however, due to the vague nature of your question we can only speculate...
My suggestion is that you try this out in various places, maybe some with clear access to the sky, and another in a crowded area and you see how the GPS behaves.
I too faced same problem while testing my Google navigation app.
The wrong location from GPS receiver is due to the lack of signal reception from GPS Satellites to GPS receiver.
This is due to the position of your GPS receiver device and also depends on the quality of GPS receiver.