casa6

import glob

import os

​

from casatools import table, measures, quanta, ms

from casatasks import casalog

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# Conversion of TOPO ephemerides to GEO (ICRS)

#

# Example:

#       import recipes.ephemerides.convertephem as ce

#       ce.convert2geo('titan.ms', 'Titan')

#

#   will find the ephemeris attached to field "Titan" in the MS "titan.ms"

#   and convert RA, Dec, and RadVel to the geocentric ref frame (ICRS)

​

​

def converttopoephem2geo(tablename='', outtablename='', overwrite=True):

    """

    converttopoephem2geo

​

    Convert the given topo ephemeris table to the geocentric ref frame.

    Converted are the RA, DEC, and RadVel columns only

​

    tablename -- name of the TOPO frame ephemeris table (in canonical CASA format)

​

    outtablename -- name of the output GEO frame ephemeris table

​

    """

​

    if type(tablename)!=str or tablename=='':

        casalog.post('Invalid parameter tablename', 'WARN')

        return False

​

    if type(outtablename)!=str or outtablename=='':

        casalog.post('Invalid parameter outtablename', 'WARN')

        return False

​

    #convert RA, DEC, and RadVel

    tbt = table()

    met = measures()

    qat = quanta()

​

    tbt.open(tablename)

    ra = tbt.getcol('RA')

    dec = tbt.getcol('DEC')

    radvel = tbt.getcol('RadVel')

    radvelunit = 'km/s'

    tmpkw = tbt.getcolkeywords('RadVel')

    if 'UNIT' in tmpkw:

        radvelunit = tmpkw['UNIT']

    elif 'QuantumUnits' in tmpkw:

        radvelunit = tmpkw['QuantumUnits'][0]

    else:

        casalog.post('Cannot determine units of radial velocity column. Assuming km/s.', 'WARN')

    mjd = tbt.getcol('MJD')

    kw = tbt.getkeywords()

    tbt.close()

​

    geodist = kw['GeoDist'] # (km above reference ellipsoid)

    geolat = kw['GeoLat'] # (deg)

    geolong = kw['GeoLong'] # (deg)

​