Spherical to Cartesian coordinates

SphericalToCartesian.cs

/// Converts Spherical to Cartesian coordinates
int earthRadius = 6367; //radius in km
private Cartesian convertSphericalToCartesian(double latitude, double longitude)
{
    var lat = DegreesToRadians(latitude);
    var lon = DegreesToRadians(longitude);
    var x = earthRadius * Math.Cos(lat) * Math.Cos(lon);
    var y = earthRadius * Math.Cos(lat) * Math.Sin(lon);
    var z = earthRadius * Math.Sin(lat);
    return new Cartesian(x, y, z);
}

private class Cartesian
{
    public double X { get; set; }
    public double Y { get; set; }
    public double Z { get; set; }
    public Cartesian(double x, double y, double z)
    {
        X = x;
        Y = y;
        Z = z;
    }
}