CODEWITHSUNDEEP
windows-phone-7geolocation
Sam
Sam

Reputation: 31

Windows Phone 7 GetDistanceTo() returns incorrect distance

I am developing a small Windows Phone application. I am storing the current location of user in the database.

Here is the code to retrieve the current location which is stored in database.

public void watcher_PositionChanged(object sender, GeoPositionChangedEventArgs<GeoCoordinate> e)
{
    CurrentLatitude = e.Position.Location.Latitude.ToString(); 
    CurrentLongitude = e.Position.Location.Longitude.ToString();
}

We need to allow user to do some activity if he is under the 400 meters from his saved location.

I am using the following code to calculate the distance.

internal double GetDistanceTo(GeoCoordinate ClientLocation)
{
    double distanceInMeter;

    GeoCoordinate currentLocation = new GeoCoordinate(Convert.ToDouble(watcher.Position.Location.Latitude.ToString()), Convert.ToDouble(watcher.Position.Location.Longitude.ToString()));
    distanceInMeter = currentLocation.GetDistanceTo(ClientLocation);

    return distanceInMeter;
}

ClientLocation : is the location saved in the database.

So my problem is that it gives extremly large distance even the user is standing at the same location(under 1 meter) which is saved in the database.

Example cordinates (extracted from device)

Saved in Database

Lat : 29.8752546310425
Long: 73.8865985870361

Current Cordinates

Lat : 29.8734102249146
Long :73.9049253463745

Distance 1780.45

Could anybody suggest me what is wrong here or a better way to get the distance between two coordinates?

Upvotes: 0

Views: 1534

Answers (1)

gbanfill
gbanfill

Reputation: 2216

According to boulter.com it is 1.11miles from A to B. Thats about 1780m, so I dont see what the problem is. Have a read of the Moveable Type help on lat and long calculations.

Upvotes: 3

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