blimpy/filterbank.py
def compute_lsrk(self):
        """ Computes the LSR in km/s

        uses the MJD, RA and DEC of observation to compute
        along with the telescope location. Requires pyslalib
        """
        ra = Angle(self.header[b'src_raj'], unit='hourangle')
        dec = Angle(self.header[b'src_dej'], unit='degree')
        mjdd = self.header[b'tstart']
        rarad = ra.to('radian').value
        dcrad = dec.to('radian').value
        last = self.compute_lst()
        tellat  = np.deg2rad(self.coords[0])
        tellong = np.deg2rad(self.coords[1])

        # convert star position to vector
        starvect = s.sla_dcs2c(rarad, dcrad)

        # velocity component in ra,dec due to Earth rotation
        Rgeo = s.sla_rverot( tellat, rarad, dcrad, last)

        # get Barycentric and heliocentric velocity and position of the Earth.
        evp = s.sla_evp(mjdd, 2000.0)
        dvb = evp[0]   # barycentric velocity vector, in AU/sec
        dpb = evp[1]   # barycentric position vector, in AU
        dvh = evp[2]   # heliocentric velocity vector, in AU/sec
        dph = evp[3]   # heliocentric position vector, in AU

        # dot product of vector to object and heliocentric velocity
        # convert AU/sec to km/sec
        vcorhelio = -s.sla_dvdv( starvect, dvh) *149.597870e6
        vcorbary  = -s.sla_dvdv( starvect, dvb) *149.597870e6

        # rvlsrd is velocity component in ra,dec direction due to the Sun's
        # motion with respect to the "dynamical" local standard of rest
        rvlsrd = s.sla_rvlsrd( rarad,dcrad)

        # rvlsrk is velocity component in ra,dec direction due to i
        # the Sun's motion w.r.t the "kinematic" local standard of rest
        rvlsrk = s.sla_rvlsrk( rarad,dcrad)

        # rvgalc is velocity component in ra,dec direction due to
        #the rotation of the Galaxy.
        rvgalc = s.sla_rvgalc( rarad,dcrad)
        totalhelio = Rgeo + vcorhelio
        totalbary  = Rgeo + vcorbary
        totallsrk = totalhelio + rvlsrk
        totalgal  = totalbary  + rvlsrd + rvgalc

        return totallsrk
def compute_lsrk(self):
        """ Computes the LSR in km/s

        uses the MJD, RA and DEC of observation to compute
        along with the telescope location. Requires pyslalib
        """
        ra = Angle(self.header[b'src_raj'], unit='hourangle')
        dec = Angle(self.header[b'src_dej'], unit='degree')
        mjdd = self.header[b'tstart']
        rarad = ra.to('radian').value
        dcrad = dec.to('radian').value
        last = self.compute_lst()
        tellat  = np.deg2rad(self.coords[0])
        tellong = np.deg2rad(self.coords[1])

        # convert star position to vector
        starvect = s.sla_dcs2c(rarad, dcrad)

        # velocity component in ra,dec due to Earth rotation
        Rgeo = s.sla_rverot( tellat, rarad, dcrad, last)

        # get Barycentric and heliocentric velocity and position of the Earth.
        evp = s.sla_evp(mjdd, 2000.0)
        dvb = evp[0]   # barycentric velocity vector, in AU/sec
        dpb = evp[1]   # barycentric position vector, in AU
        dvh = evp[2]   # heliocentric velocity vector, in AU/sec
        dph = evp[3]   # heliocentric position vector, in AU

        # dot product of vector to object and heliocentric velocity
        # convert AU/sec to km/sec
        vcorhelio = -s.sla_dvdv( starvect, dvh) *149.597870e6
        vcorbary  = -s.sla_dvdv( starvect, dvb) *149.597870e6

        # rvlsrd is velocity component in ra,dec direction due to the Sun's
        # motion with respect to the "dynamical" local standard of rest
        rvlsrd = s.sla_rvlsrd( rarad,dcrad)

        # rvlsrk is velocity component in ra,dec direction due to i
        # the Sun's motion w.r.t the "kinematic" local standard of rest
        rvlsrk = s.sla_rvlsrk( rarad,dcrad)

        # rvgalc is velocity component in ra,dec direction due to
        #the rotation of the Galaxy.
        rvgalc = s.sla_rvgalc( rarad,dcrad)
        totalhelio = Rgeo + vcorhelio
        totalbary  = Rgeo + vcorbary
        totallsrk = totalhelio + rvlsrk
        totalgal  = totalbary  + rvlsrd + rvgalc

        return totallsrk
Computes the LSR in km/s

        uses the MJD, RA and DEC of observation to compute
        along with the telescope location. Requires pyslalib