I am developing an application where I want to use Fused Location Provider. But I have some doubts, and couple of questions.
When GPS is off and I set priority to HIGH, does that mean that the GPS will be automatically turned on, or not?
Can I set UpdateLocation with Fused provider with HIGH priority on demand to save battery at least a little bit?
How can I know what Fused provider is using (is it a GPS or a network provider)?
And finally
Is Fused provider really the best choice for android location? Are there any negative points about it?
What is your opinion?
Thanks in advance.
When GPS is off and I set priority to HIGH, does that mean that GPS will be automatically turned on, or not?
No, it will not be turned on automatically. But if you use SettingsApi, will prompt a dialog to user and gives information that GPS is must be turned on. If user accepts it, the gps will be active automatically. Check the SettingsApi
How can I know what Fused provider is using (is it a GPS or a network provider)
If you use fused provider api with SettingsApi properly. It will make adequate the required settings for current location request.
Is Fused provider really the best choice for android location? Are there any negative points about it?
In my opinion, before fused provider you must deal with directly providers(Gps, network) But fused just asks you, "how accurate locations you wanna receive ?"
As in here https://developer.android.com/training/location/index.html stated very clearly that, the Google Play services location APIs are preferred over the Android framework location APIs (android.location) as a way of adding location awareness to your app. If you are currently using the Android framework location APIs, you are strongly encouraged to switch to the Google Play services location APIs as soon as possible. So I hope you got your answer.
I made a testing application for Gps, Wifi and Fused Location Provider and testing it for 2 days. It's better because it uses both of them and most of the time it's the one most accurate. Also, Gps data is a very noisy data that causes jittering, to solve this low-pass filter or other filters are used. One of the most successful filter used to get most accurate results is Kalman Filter. FusedLocationProvider use this filter same as RotationVector which is a fused sensor combines hardware and software. RotationVector uses accelerometer, gyroscope(if available), and magnetic field sensor to get and filter positition and azimuth data.
Location.getProvider for Gps with LocationManager returns "gps", Wifi returns "network", and FusedLocationProvider returns "fused".
When GPS is off and I set priority to HIGH, does that mean that the GPS will be automatically turned on, or not
Anything other than "Battery Saving" turns Gps on if available. This settings available on my Android 7.1.1 phone. Setting for location was different on previous versions of Android on user's side. As a developer to enable using Gps you should set mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
PRIORITY_HIGH_ACCURACY - Use this setting to request the most precise location possible. With this setting, the location services are more likely to use GPS to determine the location.
Setting Priority also determines battery use level too.
Can I set UpdateLocation with Fused provider with HIGH priority on demand to save battery at least a little bit?
Yes, you can set interval of location request in addition to priority.
mLocationRequest.setInterval(UPDATE_INTERVAL_IN_MILLISECONDS);
mLocationRequest.setFastestInterval(FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS);
How can I know what Fused provider is using (is it a GPS or a network provider)?
Location from Wifi never returns true for Location.hasSpeed() but Gps returns almost always true if you are outdoors. Also location.getExtras() have satellites tag which you can check for satellites which is only available for Gps. Speed may not be correct if you are walking or as far i've read so far, i haven't tried this on car, when speed it less than 5km/h it's not very accurate. I mean if you are using FLP and last location data contains speed info it's definitely from Gps.
Are there any negative points about it?
As of Android 8.0 and above there is location retrieving limit if you do not use a Foreground Service or get location on foreground while app is not paused for both FLP and LocationManager.
Also FLP requires GooglePlayService to be available on user's device and it should be above a particular version. 10 or 11 depending on which one you use. This can be trouble if you wish to publish your apps on a country, for example China, that bans Google Play Services.
The existing answers don't say why the FusedLocationProvider is better.
It is better because the API fuses from more data sources (sensors, wifi, context, history) in an intelligent and battery-saving way. Also, Google is always improving it by adding more data sources. If your app uses it, you get those improvements for free.
Related
I have a real quick question. As far as I know the Geolocator package uses the Android FusedLocationProviderClient to access the users location. Does this client use all the permitted opportunities to get the location (like gps,wlan,mobile networks...) or does this only use the gps data?
All together: How does the FusedLocationProviderClient get the data for the users location?
Thanks for the answer.
The fused location provider manages the underlying location technologies, such as GPS and Wi-Fi, and provides a simple API that you can use to specify the required quality of service. For example, you can request the most accurate data available, or the best accuracy possible with no additional power consumption
We need not explicitly choose either GPS or Network location Provider, as the “Fused Location Provider” automatically chooses the underlying technology and gives the best location as per the need.
REF : https://developers.google.com/location-context/fused-location-provider/
So, regaring you question about the accuracy of the location it totally depends whethere the location was enabled and the fusedLocation stored it for furture use.
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
Let's assume I'm used the Android fused location API to request highly accuracy location reporting. For example,
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(FASTEST_UPDATE_INTERVAL*2);
mLocationRequest.setFastestInterval(FASTEST_UPDATE_INTERVAL);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
LocationServices.FusedLocationApi
.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this)
This results in my location listener getting called up to every FASTEST_UPDATE_INTERVAL. If I set FASTEST_UPDATE_INTERVAL to be short I know that the GPS radio will not be turned off between location updates. I know this from various sources such as Fused Location Provider unexpected behavior and https://www.quora.com/Why-does-GPS-use-so-much-more-battery-than-any-other-antenna-or-sensor-in-a-smartphone.
My question is what is the smallest value of FASTEST_UPDATE_INTERVAL that will result in the GPS radio being turned off between location updates?
I anticipate there will not be a clear answer to this question, and that it will depend on the phone hardware, the Google Play version and probably other hardware and software factors. Nonetheless a general answer would be helpful.
This question is important because I am interested in using high accuracy locating but minimizing battery use. To a point I am happy to increase FASTEST_UPDATE_INTERVAL if it will save power.
Wouldn't it be nice if the google fused location services used the device's motion detectors (if they exist) to work out when it was stationary and if so simply turned off the GPS radio until the device moved.
Even if you found an answer, I wouldn't count on it remaining the same between devices, OS versions, or Google Play versions. If you absolutely don't want GPS, don't used the fused provider. Use the network provider from the base LocationManager.
As for using motion detectors- they don't exist. It has an accelerometer, but to an accelerometer staying still and traveling at a constant 50mph look exactly the same (traveling at constant speed is 0 acceleration). It might not be a good optimization anyway- getting a lock on multiple GPS satellites takes several seconds. You don't want to keep turning that on and off if someone wants accuracy.
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.
In my application I would like to determine the user's current location. I do however have a couple of questions in this regard:
There are different Location Providers, which one is the most accurate? The GPS Provider or the Network Provider?
In how far do those available provider differ? How do they function?
Could you please provide me with some code-snippets or tutorials on how to get started with implementing GPS functionality in my application?
There are 3 location providers in Android.
They are:
gps –> (GPS, AGPS): Name of the GPS location provider. This
provider determines location using satellites. Depending on
conditions, this provider may take a while to return a location fix.
Requires the permission android.permission.ACCESS_FINE_LOCATION.
network –> (AGPS, CellID, WiFi MACID): Name of the network
location provider. This provider determines location based on
availability of cell tower and WiFi access points. Results are
retrieved by means of a network lookup. Requires either of the
permissions android.permission.ACCESS_COARSE_LOCATION or
android.permission.ACCESS_FINE_LOCATION.
passive –> (CellID, WiFi MACID): A special location provider for
receiving locations without actually initiating a location fix. This
provider can be used to passively receive location updates when other
applications or services request them without actually requesting the
locations yourself. This provider will return locations generated by
other providers. Requires the permission
android.permission.ACCESS_FINE_LOCATION, although if the GPS is not
enabled this provider might only return coarse fixes. This is what
Android calls these location providers, however, the underlying
technologies to make this stuff work is mapped to the specific set of
hardware and telco provided capabilities (network service).
The best way is to use the “network” or “passive” provider first,
and then fallback on “gps”, and depending on the task, switch between
providers. This covers all cases, and provides a lowest common
denominator service (in the worst case) and great service (in the best
case).
Article Reference : Android Location Providers - gps, network, passive By Nazmul Idris
Code Reference : https://stackoverflow.com/a/3145655/28557
-----------------------Update-----------------------
Now Android have Fused location provider
The Fused Location Provider intelligently manages the underlying location technology and gives you the best location according to your needs. It simplifies ways for apps to get the user’s current location with improved accuracy and lower power usage
Fused location provider provide three ways to fetch location
Last Location: Use when you want to know current location once.
Request Location using Listener: Use when application is on screen / frontend and require continues location.
Request Location using Pending Intent: Use when application in background and require continues location.
References :
Official site : http://developer.android.com/google/play-services/location.html
Fused location provider example:
GIT : https://github.com/kpbird/fused-location-provider-example
http://blog.lemberg.co.uk/fused-location-provider
--------------------------------------------------------
GPS is generally more accurate than network but sometimes GPS is not available, therefore you might need to switch between the two.
A good start might be to look at the android dev site. They had a section dedicated to determining user location and it has all the code samples you need.
http://developer.android.com/guide/topics/location/obtaining-user-location.html
There are some great answers mentioned here. Another approach you could take would be to use some free SDKs available online like Atooma, tranql and Neura, that can be integrated with your Android application (it takes less than 20 min to integrate).
Along with giving you the accurate location of your user, it can also give you good insights about your user’s activities. Also, some of them consume less than 1% of your battery