public double distanceFrom(Location b) {
        
        if (b.locType != this.locType) {
            System.out.println("Location.distanceFrom: sorry type conversion not implemented yet");
            return -1;
        } else {
            double rr = -1;
            switch (locType) {
                case NORTHINGEASTING: rr = NEDistance(b);
                    break;
                case LATLONG: rr = LatLonDistance(b);
                    break;
                case XY: rr = XYDistance(b);
                    break;
            }
            return rr;
        }
        
    }