獲取不正確的距離使用GPS lattitude經度

Question

這是我的代碼：

private final static double[] multipliers = { 
     1.0, 1.0936133, 0.001, 0.000621371192 
}; 

private final static String[] unitstrings = { 
     "m", "y", "km", "mi" 
}; 

private void updateMeasurement() { 
    double distance = calcGeoDistance(startLat, startLon, currentLat, currentLon) * multipliers[unitindex]; 
    String distanceText = "" + RoundDecimal(distance, 2) + " " + unitstrings[unitindex];  
    ((TextView)findViewById(R.id.distance)).setText(distanceText); 
} 

private double calcGeoDistance(final double lat1, final double lon1, final double lat2, final double lon2) 
{ 
    double distance = 0.0;  
    try 
    { 
     final float[] results = new float[3];   
     Location.distanceBetween(lat1, lon1, lat2, lon2, results);   
     distance = (double)results[0]; 
    } 
    catch (final Exception ex) 
    { 
     distance = 0.0; 
    } 
    return distance; 
} 

我報復8310公里當我搖動手機。

Answer 1

public float distanceFrom(float lat1, float lng1, float lat2, float lng2) { 

    double earthRadius = 3958.75; 
    double dLat = Math.toRadians(lat2-lat1); 
    double dLng = Math.toRadians(lng2-lng1); 
    double a = Math.sin(dLat/2) * Math.sin(dLat/2) + Math.cos(Math.toRadians(lat1)) *Math.cos(Math.toRadians(lat2)) * Math.sin(dLng/2) * Math.sin(dLng/2); 
    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a)); 
    double dist = earthRadius * c; 
    int meterConversion = 1609; 
    return new Float(dist * meterConversion).floatValue(); 
} 

Answer 2

您是否正確使用Long和Lat度數？這將有助於看到的值要傳遞的

double startLatitude = pointStart.getLatitudeE6()/DEG_RATE; 
double startLongitude= pointStart.getLongitudeE6()/DEG_RATE; 
double endLatitude = pointEnd.getLatitudeE6()/DEG_RATE; 
double endLongitude= pointEnd.getLongitudeE6()/DEG_RATE; 
float[] result = new float[1]; 
Location.distanceBetween(startLatitude, startLongitude, endLatitude, endLongitude, result); 

凡pointStart和pointEnd是com.google.android.maps.GeoPoint

參考 -

http://www.java2s.com/Code/Android/Core-Class/GetDistancebetweentwoGeoPoint.htm