I would like to get accurate location from NETWORK_PROVIDER keeping GPS turned OFF in order to save battery. This seems impossible becasue android, when ACCESS_FINE_LOCATION is specified, turns on GPS even when location is not requested to GPS_PROVIDER.
I have added:
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
into the Manifest. I needed that in order to avoid android obfuscating accurate position.
I registered updates just using NETWORK_PROVIDER and not GPS_PROVIDER:
myLocationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,
60000, 0, locationListener);
GPS turns on anyhow. How can I avoid it (without forcing the user to disable GPS, that actually works but is undesired)?
Sounds strange, if you haven't requested location updates from the gps-provider, it shouldn't boot up the GPS.
Let me give you a piece of advice though - don't count on the network provider to give you 'fine' accuracy unless you're sitting on a wifi that google knows the position of.
Positioning based on cell towers usually have accuracy of about 500 - 2000m, perhaps 3-500m in city centers.
Use either ACCESS_FINE_LOCATION is you want GPS to be used or ACCESS_COARSE_LOCATION if you don't want to use GPS.
If your positioning technologies are disabled to save power, how can you expect to get an accurate position? That would be like expecting a car to take you to work but not wanting to put gas in it. tanstaafl.
As mentioned above, WiFi positioning can give you pretty good location acuracy if you are around a couple of APNs that Google knows about. Given enough time and enough people using their phones, Google will eventually learn every APN that doesn't move.
Related
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.
Some resources say getLastKnownLocation() merely gives a location of some previous app's Location Change Listener.
But one thing I feel is missing from the conversation -- if the phone has GPS enabled, isn't this GPS tracking/updating as the phone moves? So if I call getLastKnownLocation(), isn't it getting the current GPS from the phone's constantly-updated GPS?
If so, then why do people warn against using it / accuse it of potentially getting a "stale" location? If the GPS is being tracked / updated, and getLastKnownLocation() makes a one-time grab of it's current position, what makes getLastKnownLocation() bad?
What am I mistaken about the Locations service or GPS?
The documentation says: Returns a Location indicating the data from the last known location fix obtained from the given provider.
Also, about the "out of date location": This can be done without starting the provider. Note that this location could be out-of-date, for example if the device was turned off and moved to another location. ("This" refers to getting the last known location).
Also, taken from LocationProvider docs:
Each provider has a set of criteria under which it may be used; for example, some providers require GPS hardware and visibility to a number of satellites; others require the use of the cellular radio, or access to a specific carrier's network, or to the internet. They may also have different battery consumption characteristics or monetary costs to the user.
if the phone has GPS enabled, isn't this GPS tracking/updating as the phone moves?
Well, it is, but not constantly. This has to do with battery consumption, if the phone was constantly updating the GPS location, the battery life would suffer a lot. The GPS location is usually updated when some app requests it. But even that request is not guaranteed to succeed. For example, suppose your going into a tunnel. Some application requests to update the GPS coordinates right before entering the tunnel and it succeeds. Now, you've entered the tunnel, which is 5km long. Most probably your device won't be able to get a GPS fix from the tunnel, so for the next 5km (at least) getLastKnownLocation() will return an outdated value, since the devices last known location was at the entrance of the tunnel.
What you could do is explicitly request to update the GPS location, that however might take some time and there are no guarantees that it will succeed.
You have the assumption "if the phone has GPS enabled, isn't this GPS tracking/updating as the phone moves". This assumption is incorrect. The GPS functionality takes up a lot of battery life so it should be used sparingly and almost certainly not all the time.
Id like to narrow down the location of a phone to the cm or less than a foot (nothing creepy I promise :). Say there was a room full of people I would like 1 user to be able to look though an augmented reality view on their phone to find another user.
Only problem is the location data, I know gps is probably out since I think its only accurate to 10-15 meters? Could you do something with the wifi points, ie have a couple and measure ping time between them to work out location? Or does this technology already exist? Thanks C
Android provides basically two location provider :
GPS
Network
GPS is the most accurate source which you don't want to use and it's slow.
Network location provider is false but less accurate than gps.
So the only hope is GPS.
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.
How would I verify/ track device location within a 5' accuracy? I've heard of people using cell towers/ gps combinations.
As far as I know, the only way to get a 5 feet accuracy figure is to use GPS, then it still isn't always that accurate depending on how good a fix of the satellites (clear view to the sky) you have.
Cell tower / Wifi triangulation methods only serve to speed up positioning and will seldom (if ever) be more accurate than satellite positioning methods.
GPS is the way to go. Cell towers won't cut it. In Android (and I believe iOS) the system will provide you with an accuracy reading in addition to the actual location. You could use this value to determine whether the value you've received should be uploaded to your server. Keep in mind using the GPS is very battery intensive and there's no guarantee of how good the accuracy will be. Depending on conditions you may not be able to achieve 5' precision.
As #CommonsWare points out, 5' is really unrealistic anyway although you can get close.
As CommonsWare says you will not get much better that 10 metters accuracy in a consummer-grade device. Even in open sky, the atmosphere characteristcs change minute by minute and thats enough to change the GPS readings.
However, it's teoreticaly possible to increase accuracy if you could get all of the following:
1-There are some stationary GPS receiver stations with fixed known locations which measure the current GPS signals deviation. You would need to have one of those close to you and have access to the data in real time.
2-You would need to have low level access to your phone GPS receiver to read the unprocessed data received from sattelites. This would be different from device to device, and as far as I know, no supplier is providing this access.
3-Finnaly, you would need to do all the calculations required to determine your location applying the deviations got from point 1 above.
good luck.
The only way you can get this type of accuracy is with WAAS. As far as I know, there are no Android handsets that can receive WAAS corrections. If this is for a specific controlled situation, you could use a bluetooth gps receiver with WAAS, and only in WAAS supported locations. However, if this was for a wider deployment, then I think you are out of luck.