def _to_parent_frame(self, *args, **kwargs):
        """Conversion from Topocentric Frame to parent frame
        """
        lat, lon, _ = self.latlonalt
        m = rot3(-lon) @ rot2(lat - np.pi / 2.) @ rot3(self.heading)
        offset = np.zeros(6)
        offset[:3] = self.coordinates
        return self._convert(m, m), offset