location monitoring in a iphone app - iphone

Question

I am an newbie with iphone app development. I would like to capture location information without using GPS but only with Cell tower info and Wifi data. To enable this I am using the CLLocationManager to capture location information,
self.locationManager = [[CLLocationManager alloc] init];
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
[locationManager startMonitoringSignificantLocationChanges];
-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations {
CLLocation *newLocation = [locations lastObject];
float latitude = newLocation.coordinate.latitude;
float longitude = newLocation.coordinate.longitude;
NSTimeInterval timeStamp = [[NSDate date] timeIntervalSince1970];
// NSTimeInterval is defined as double
NSNumber *timeStampObj = [NSNumber numberWithDouble: timeStamp];
NSLog(#"latitude %f and longitude %f", latitude, longitude );
NSLog(#"%d", [timeStampObj integerValue]);
NSMutableArray *numArray = [[NSMutableArray alloc]initWithObjects:[NSNumber numberWithDouble:latitude],[NSNumber numberWithDouble:longitude], timeStampObj, nil];
}
When I use the above code when the app is launched I see that the app requests for accessing location services. Once this is accepted, I am not sure if the app is making use of GPS to get the location information as I see a small arrow pointing out, which seems as though GPS is being used to obtain the location information, which is not what I require. I would want the location information to be captured using WiFi and Cell Tower information only.
Also is there a frequency in which this location information gets updated, as there is an initial update of location after that I do not see the location getting modified even after the phone is being continuously moved.

Answer 1

If you use this:
[locationManager startMonitoringSignificantLocationChanges];
You are only getting GPS uploads when a significant change happens (for example, when you move from a telephony tower to other).
You cannot choose if you want to use GPS or towers from the code.