iOS Location Services Methode zum Filtern ungültiger/ungenauer Standorte

Question

Ich verwende Location Services in einigen meiner Apps. Ich habe eine Methode, die ich in meiner locationManager:didUpdateToLocation:fromLocation: Methode verwenden, um schlechte, ungenaue oder zu weit entfernte Standorte herauszufiltern. Und um GPS-Jitter zu minimieren. Hier ist, was ich verwende:

/** 
* Check if we have a valid location 
* 
* @version $Revision: 0.1 
*/ 
+ (BOOL)isValidLocation:(CLLocation *)newLocation withOldLocation:(CLLocation *)oldLocation { 

    // Filter out nil locations 
    if (!newLocation) return NO; 

    // Filter out points by invalid accuracy 
    if (newLocation.horizontalAccuracy < 0) return NO; 
    if (newLocation.horizontalAccuracy > 66) return NO; 

    // Filter out points by invalid accuracy 
    #if !TARGET_IPHONE_SIMULATOR 
    if (newLocation.verticalAccuracy < 0) return NO; 
    #endif 

    // Filter out points that are out of order 
    NSTimeInterval secondsSinceLastPoint = [newLocation.timestamp timeIntervalSinceDate:oldLocation.timestamp]; 
    if (secondsSinceLastPoint < 0) return NO; 

    // Make sure the update is new not cached 
    NSTimeInterval locationAge = -[newLocation.timestamp timeIntervalSinceNow]; 
    if (locationAge > 5.0) return NO; 

    // Check to see if old and new are the same 
    if ((oldLocation.coordinate.latitude == newLocation.coordinate.latitude) && (oldLocation.coordinate.longitude == newLocation.coordinate.longitude)) 
     return NO; 

    return YES; 

}//end 

Hat jemand Verbesserungen an dieser Methode, um es genauer zu machen? Ist zu hoch von horizontalAccuracy und wird viele ungültige Standorte erhalten? Soll ich das senken?

Gibt es eine Möglichkeit, den "Jitter" zu bekommen, den GPS auf dem iPhone gibt?

Answer 1

Zusätzlich zu diesen gibt es eine weitere ich benutze:

if(self.lastKnownLocation) 
{ 
    CLLocationDistance dist = [newLocation distanceFromLocation:self.lastKnownLocation]; 

    if(dist > newLocation.horizontalAccuracy) 
    { 
      //..... 
    } 
} 

Wo self.lastKnownLocation tatsächlich der letzte gültige Lage ist, ich habe und es ist ein:

@property(nonatomic, copy) CLLocation *lastKnownLocation; 

Answer 2

-(void)locationManager:(CLLocationManager *)manager 
    didUpdateToLocation:(CLLocation *)newLocation 
      fromLocation:(CLLocation *)oldLocation 
{ 
if (!newLocation) 
    { 
     NSLog(@"Filter out points by invalid accuracy"); 
     return; 
    } 

    // Filter out points by invalid accuracy 
    if (newLocation.horizontalAccuracy < 0) 
    { 
     return; 
    } 
    if(oldLocation.coordinate.latitude>90 && oldLocation.coordinate.latitude<-90 && oldLocation.coordinate.longitude>180 && oldLocation.coordinate.longitude<-180) 
    { 
     NSLog(@"old"); 
     return; 
    } 
    if(newLocation.coordinate.latitude>90 || newLocation.coordinate.latitude<-90 || newLocation.coordinate.longitude>180 || newLocation.coordinate.longitude<-180) 
    { 
     NSLog(@"new"); 
     return; 
    } 

    /////// 
    NSDate *eventDate=newLocation.timestamp; 
    NSTimeInterval eventinterval=[eventDate timeIntervalSinceNow]; 


    if (abs(eventinterval)<30.0) 
    {   
     if (newLocation.horizontalAccuracy>=0 && newLocation.horizontalAccuracy<20) 
     { 
      **//finally you are getting right updated value here....** 
     }   
    }   
} 

Answer 3

Sie können diese Kasse

https://medium.com/@mizutori/make-it-even-better-than-nike-how-to-filter-locations-tracking-highly-accurate-location-in-774be045f8d6

Die Hauptidee ist es, die Daten in der Methode didUpdateLocation:

Die Filtermethode ist einfach so Filer:

func filterAndAddLocation(_ location: CLLocation) -> Bool{ 
    let age = -location.timestamp.timeIntervalSinceNow 

    if age > 10{ 
     return false 
    } 

    if location.horizontalAccuracy < 0{ 
     return false 
    } 

    if location.horizontalAccuracy > 100{ 
     return false 
    } 

    locationDataArray.append(location) 

    return true 

}