CODEWITHSUNDEEP
androidgpstracking
Md. Sajedul Karim
Md. Sajedul Karim

Reputation: 7065

Android GPS location accuracy issue

I am working on gps tracking apps in android. Here is my code architecture:

  1. BackgroundSyncService : A service class that is used for getting location update. Here GoogleApiClient is initialized and implements others Location related methods.
  2. AppRunCheckerReceiver : A BroadcastReceiver class that will check if my BackgroundSyncService is running or not in a time interval. If it stopped then it start.
  3. 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.
  4. 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:

  1. How can i make accuracy level near 99%. Is there any problem on my code architecture?
  2. Does GPS accuracy depends on device configuration? if YES then what can I do for low configuration device?
  3. How Uber, Go-JEK etc. ride sharing apps works for all device? Is they have extra coding for GPS only?
  4. 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.

Upvotes: 36

Views: 19070

Answers (2)

Pararth
Pararth

Reputation: 8134

First, (and second)

  1. How can I make accuracy level near 99%. Is there any problem on my code architecture?

  2. 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.

  1. 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

  2. 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

Upvotes: 4

ugur
ugur

Reputation: 3654

  1. 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.

  1. 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
  1. 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.

  1. 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:

Upvotes: 8

Related Questions