Getting really bad accuracy from CLLocationManager

Question

I'm using CLLocationManager to get users location.

I want to get a single location update.

My problem is that I'm getting really bad horizontalAccuracy

location is %@ <+xx.xxxxxx,+yy.yyyyyyy> +/- 3881.91m

verticalAccuracy: 65.4401861912846, horizontalAccuracy: 3881.90892434957

Code:

fileprivate lazy var locationManager: CLLocationManager = {
    let manager = CLLocationManager()
    manager.desiredAccuracy = kCLLocationAccuracyBest
    manager.delegate = self
    manager.requestAlwaysAuthorization()
    manager.pausesLocationUpdatesAutomatically = false
    manager.desiredAccuracy = kCLLocationAccuracyBest
    manager.distanceFilter = kCLDistanceFilterNone
    return manager
}()

override init() {
    super.init()
    locationManager.startUpdatingLocation()
}

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    guard let mostRecentLocation = locations.last else {
        return
    }
    
    let verticalAccuracy =  mostRecentLocation.verticalAccuracy
    let horizontalAccuracy = mostRecentLocation.horizontalAccuracy
    
    print("location is %@", mostRecentLocation)
    print("verticalAccuracy: \(verticalAccuracy), horizontalAccuracy:\(horizontalAccuracy)")
}

Any suggestions why is this happening? I'm in a room next to a window so i except to get bad accuracy but not that bad.

Thanks

---

I'm getting ridiculous results.

I got horizontalAccuracy of 15,000 m.

When i go out doors it works great but in doors should not be as bad as this.

Using Cellular triangulation and wifi should give a lot better results.

---

after 20 minutes i started to get good results of +- 50 m accuracy in doors.

Answer 1

I suggest you add a condition to make sure that you will just be using a location that have a better accuracy. On my case I use 20 as the desired horizontal accuracy on below example.

Example:

    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {

         locationManager.stopUpdatingLocation()

         if locations.last!.horizontalAccuracy < 20 {
            //Only use location that enters here
         }
         else {
            //If the accuracy is not met then start updating location again and if possible increase more the accuracy (use kCLLocationAccuracyBestForNavigation if you really need it). Make sure that you use the desired accuracy and filter properly to avoid draining battery.
            locationManager.startUpdatingLocation()
         }
    }