Develop Reference

Android GPS location accuracy issue

I am working on gps tracking apps in android. Here is my code architecture:
BackgroundSyncService : A service class that is used for getting location update. Here GoogleApiClient is initialized and implements others Location related methods.
AppRunCheckerReceiver : A BroadcastReceiver class that will check if my BackgroundSyncService is running or not in a time interval. If it stopped then it start.
GpsEnableReceiver : A BroadcastReceiver it will fire if gps status changed. It will check if my BackgroundSyncService is running or not in a time interval. If it stopped then it start.
InternetConnectionStateReceiver : A BroadcastReceiver it will fire when internet status changed. It will check if my BackgroundSyncService is running or not in a time interval. If it is stopped, then it start.
In my BackgroundSyncService service I initialize the GoogleApiClient using this way:
public void setLocationLocationRequest() {
try {
googleApiClient = new GoogleApiClient.Builder(this).addConnectionCallbacks(this)
.addOnConnectionFailedListener(this).addApi(com.google.android.gms.location.LocationServices.API).build();
locationRequest = new LocationRequest();
locationRequest.setInterval(3000);
locationRequest.setFastestInterval(3000);
locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
googleApiClient.connect();
} catch (Exception e) {
}
Here accuricy is LocationRequest.PRIORITY_HIGH_ACCURACY and interval is
locationRequest.setInterval(3000)
here is the GoogleApiClient implementation code.
This application GPS info section contains Latitude longitude and Accuracy parameter
My Findings: in onLocationChanged(Location location) method I check the accuracy of Location object in this way : location.getAccuracy(). Here if accuracy is less than 50 meter, then I accept it.
In 85% of the cases it working like a charm. It sending me exact location from GPS. But in 15% cases, it sending me inaccurate location like more >300 meter.
The 15% device are low cost China brand mobile.
My Questions:
How can i make accuracy level near 99%. Is there any problem on my code architecture?
Does GPS accuracy depends on device configuration? if YES then what can I do for low configuration device?
How Uber, Go-JEK etc. ride sharing apps works for all device? Is they have extra coding for GPS only?
My application is for Bangladesh. Here internet is slow. Is it has negative impact on GPS accuracy?
Thanks in advance for this thread. And also sorry for bad english.

How can i make accuracy level near 99%. Is there any problem on my code architecture?
This is real life scenario. You cannot ensure that all the location providers will work as expected. You should ask for best available position.
a) Does GPS accuracy depends on device configuration?
YES. Some devices may have older GPS chipsets which can only track GPS signals (USA) since there are other positioning systems like Galileo (Europe), GLONASS (Russia), QZSS (Japan) and Beidou (China). The more the chipset support for these types the more chance you get to track more satellite hereby position fix. Also TTFF (time to first fix) depends on how many channels do the gps receiver has.
b) If YES then what can i do for low configuration device?
Since this is a hardware issue, you cannot do anything here. But other location sources can compensate the lack of GPS data such as AGPS (aided gps), wifi and cellular positioning. Also there are some paid options which provides a database to locate your device using wifi access points and cellids (they claim that they provide best solution on wifi but i m not sure as I dont use it. you can check it out http://combain.com). Wifi and cellid also depends on how many wifi access point and cell tower available around and how far they are (signal strength). If you need 50m accuracy, cellular positioning has nothing to do but wifi has a chance to get closer to this value.
Some study results from 2009 [3]
3G iPhone w/ A-GPS ~ 8 meters
3G iPhone w/ wifi ~ 74 meters
3G iPhone w/ Cellular positioning ~ 600 meters
How Uber, Go-JEK etc. ride sharing apps works for all device? Is they have extra coding for GPS only?
They may have specific Location strategies but it will based on using other sources during GPS outage.
My application is for Bangladesh. Here internet is slow. Is it has negative impact on GPS accuracy?
Other answers claims that internet is not related to GPS. Yes it is true it is not related to GPS but location. AGPS uses internet to fetch 3 types of data (Satellite signals, almanac and ephemeris) which assist GPS to provide position fix faster. If ephemeris and almanac are outdated or the device moved several hundred km from the previous position fix then it is called cold start and takes around 12-15min without AGPS.
Fused location provider already knows how to provide best solution with these configurations, so you should bless it.
References:
[1] http://gpssystems.net/agps/
[2] http://gpsinformation.net/main/almanac.txt
[3]
https://communityhealthmaps.nlm.nih.gov/2014/07/07/how-accurate-is-the-gps-on-my-smart-phone-part-2/

First, (and second)
How can I make accuracy level near 99%. Is there any problem on my code architecture?
Does GPS accuracy depends on device configuration? If YES then what can I do for low configuration device?
Both - device configuration and code architecture, are important here. If you are already at an 85% success rate, the code architecture is alright I think.
As far as GPS goes, line-of-sight is an important factor when it comes to device configurations and accuracy.
Although a low cost mobile could return an accurate location with a clear line-of-sight. You can try running 2 cycles more/waiting to attain higher accuracy.
In a worst case scenario and for what its worth, you can also try retrieving location using the LocationManager and GPS provider technique which works as a fallback in the 15% just to compare and ensure you are using the most accurate location you can get.
Location Strategies put it as
In most cases, you'll get better battery performance, as well as more
appropriate accuracy, by using the Location Services API.
How Uber, Go-JEK etc. ride sharing apps works for all device? Is they have extra coding for GPS only?
They do work but not always with highest of accuracy for locations received within the app. If there are any location hacks for us developers, we need to find them, maybe a 5th page google search result :) or benefit from the open source environment. For me, best practices and android repo links suffice. You have already followed posts like Receive location updates
My application is for Bangladesh. Here Internet is slow. Is it has negative impact on GPS accuracy?
No relation between Internet and LocationManager + GPS_PROVIDER

Check if the device is STILL (Not Moving) to ignore onlocation changed events in Android

Hi i am working on a real time location tracking application where i have used Fused Location provider Api. I was able to get the location updates when the device is moving. But i was also able to get the location updates even if the device is stationary on a table when i am indoor. So I have calculated the distance between the last location and the current location triggered in Onlocationchanged event and checked whether the distance is less than 30 metres, to know the device is actually moving. But sometimes the distance i get is greater than 400 metres (indoor/Device is Stationary). How Can i ignore the onlocationchange event when i am indoor? Any suggestions are appreciated.Thanks in advance.

Unfortunately I don't believe there's much you can do about it.
The reason you see those updates with great changes it's because indoors, you won't get a GPS lock, so the device is relying on cell tower and WiFi hotspot triangulation to determine your location, and something around 200m to 1km is the best you'll get with this kind of technology.
A possible attempt to hack-around it would be to:
check the source and precision of the location update
use the activity recognition API to guess if the device really moved
but both are a hack, around the technology limitation and might not be as reliable.

Geolocation with GPS very slow for an android app

I'm using intel xdk and cordova for an android app that uses geolocation this is the code that i use:
if(navigator.geolocation) {
navigator.geolocation.getCurrentPosition(geolocalizacion,error,{enableHighAccuracy:true, maximumAge:Infinity, timeout:100000});
} else {
handleNoGeolocation(false);
}
I don't want to use the 'google location service' because, if that option is disabled, some people can get lost trying to find it in settings, so i'm using enableHighAccuracy:true in order to use GPS.
However with that it takes so much time, almost a minute to call the success function 'geolocalizacion' when the app is used indoors. I know that GPS is better in outdoors (in that case it takes 5 or 7 seconds) but i think 1 minute is too much for indoors.
Am i doing something wrong?
Is there a way to make faster the geolocation with GPS?
or a way to activate the 'google location service' without the user doing anything?.

The GPS signals transmitted by GPS satellites are very weak if you are not located outside. Even if you are outside, weather conditions, tall buildings and other large metal structures can hide or degrade the GPS signal. In addition, the GPS receivers inside of your typical phone or tablet are very low grade receivers and antennas, they are not as capable as the more expensive dedicated GPS devices, due to compromises associated price and physical size.
You should really take a two prong approach: get an initial reading using the "coarse" geo reading, with the geo cache enabled. The coarse reading will use the wifi, network, GPS and cached readings and return it's best estimate based on the parameters you specify, usually within a very reasonable time frame.
Then, after you've established an approximate position (which can be very accurate, as #SeahawksRdaBest points out, if based on the current wifi), switch to the "fine" location setting to get an accurate position. This part of your app can run in the background so it doesn't interrupt the responsiveness of your app, and can then update the position information in your app as more accurate position data becomes available.
One thing to keep in mind, many users have the GPS turned off because it severely degrades battery life. If all your app needs is to "find a restaurant nearby" then the coarse location should be good enough, since you're probably more interested in placing the destination on the map. This will be much more battery friendly, and is one of the reasons that the geo settings on the more recent Android devices have changed to make it harder for an app to enable GPS programmatically.
I see you've added the intel-xdk tag, so you might want to checkout this little geolocation test app that I've put together at https://github.com/xmnboy/hello-cordova. It needs a little work but should help you with some experimentation between coarse and fine settings.

I think you can diversify your app a little.
For example if you are indoors and have a WiFi connection why not use that to triangulate your position? WiFi is highly accurate because theoretically it covers a small space so the phone would know exactly where it is and return a position quickly.(if done right in my experience usually <10 secs).
If a Wifi connection is not found(outdoors). You can always drop back to GPS to provide the coordinates. Plus Gps is "fastest" outside anyways.
Checkout these pages: Stackoverflow discussion. Location Manager Android.
If you want to get really fancy you can even use the Geocoder Android library to get Location addresses etc in human readable form.

Google maps - distanceTo vs proximity alert vs geofence

I'm building an app for mobile which needs to monitor the distance between the user's location and multiple location markers at regular intervals. From what I have read here and on other sites, I have three options:
1) use the distanceTo and distanceBetween functions to calculate the distance between the user's location and each location marker
2) use proximity alerts associated with each marker location
3) use geofences associated with each marker location as per Creating and Monitoring Geofences
Which approach is the best to use in light of (a) ease of implementation, (b) battery drain, and (c) gps / location accuracy? Given that I am designing predominantly for mobile, I am assuming that wifi will not always be available.

An important note on the Google Play GeoFencing API. I've found that the GeoFencing never intelligently retrieves locations from the GPS hardware. The GeoFence API will observe the most accurate location available from the OS or if no recent location reading is available, it will cause a location to be calculated from Wifi / Cellular. (which sucks because cellular is wildly inaccurate and wifi is often unavailable)
So to get at all responsive or accurate results out of the Geofencing API you have to set up your Geofences and then poll the GPS hardware on an interval, not even doing anything with the result received, so that under the surface you are providing worthwhile data to the OS.
I can't speak specifically to the behaviour of LocationManager.addProximityAlert but I doubt it behaves any differently. You could really use either and the results and performance will likely be identical because the heavy lifting is done by waking up the GPS manually.
As for how to implement your current distance to your fences, none of the proximity APIs have an interface to determine this for you. In the situation I describe above when the GPS poll occurs, instead of doing nothing with the result, I'd use it with distanceBetween to update the distance between myself and the points I've set my GeoFences at.

GPS Location returns zero speed always

I have code that successfully gets location updates from multiple providers and filters them to give a current best estimate.
I added code to check for the returned Location.hasSpeed() and .hasBearing() values to do some bearing related calculations when the user is actually moving.
It all works fine on a Huawei Sonic running 2.3.3, but on the Google Nexus S running 4.0.4 the GPS provider's Location always returns false for .hasSpeed() and 0 for .getSpeed().
When I register my location listener, the GPS provider returns true for .supportsSpeed() but it never returns the speed in a Location even when the accuracy is down to 30m and it is physically moving (in a car, on the dashboard for max reception, screen on).
Is there some difference from 2.3.x to ICS 4.x?
Do I have to implement my own speed calculation even when the provider reports support?

Google Nexus S has history of problems with GPS. I don't think that it's specifically related to ICS. Have you tried Factory data reset the phone and then retry it?