def compute_lst(self):
        """ Compute LST for observation """
        if self.header[b'telescope_id'] == 6:
            self.coords = gbt_coords
        elif self.header[b'telescope_id'] == 4:
            self.coords = parkes_coords
        else:
            raise RuntimeError("Currently only Parkes and GBT supported")
        if HAS_SLALIB:
            # dut1 = (0.2 /3600.0) * np.pi/12.0
            dut1 = 0.0
            mjd = self.header[b'tstart']
            tellong = np.deg2rad(self.coords[1])
            last = s.sla_gmst(mjd) - tellong + s.sla_eqeqx(mjd) + dut1
            # lmst = s.sla_gmst(mjd) - tellong
            if last < 0.0 : last = last + 2.0*np.pi
            return last
        else:
            raise RuntimeError("This method requires pySLALIB")
Compute LST for observation