void SensorAngleUpdated(object sender, UpdatedMeasureEventArgs e)
 {
     SensorAngle = e.Measure.Angle;
     Invalidate();
 }
 protected void OnUpdatedMeasure(UpdatedMeasureEventArgs eventArgs)
 {
     var handler = UpdatedMeasure;
     if (handler != null)
         handler(this, eventArgs);
 }