casa6

# Function to get Az, El for a particular source

​

#date= '2010/02/02'

from numpy import *

from casac import *

​

qa = casac.quanta()

me = casac.measures()

​

​

#obsMeas = me.observatory('ALMA')

#srcCoord = 'J2000 17h52m0s 9d39m0s'

def getazel(obs,srcname,srcCoord,date,tref):

    """

    Calculate azimuth and elevation of a given source coordinates

    Input:

    observatory  observatory name known to CASA (e.g. 'ALMA')

    srcCoord     source coordinates (RA,Dec) with epoch in a string (e.g. 'J2000 17h45m0.0s -29d00m00.0s' )

                 or known ephemeris source name 

    date         date in a string (YYYY/MM/DD or YYYY-MM-DD)

    tref         time reference (tref='UTC-3' or 'CDT' for Chilean daylight saving time,

                                      'UTC-4' or 'CLT' for Chilean standard time,

                                      'LST', or 'UTC')

    Output:

    vector of az values,el values,time,utctime 

    TT - 2012.04.19 

    """

# original 2010.02.02 TT

# modified 2012.04.19 TT

    t=qa.quantity(date)

    if t['unit'] != 'd':

        msg = 'Cannot decode date (format should a string with YYYY/MM/DD or YYYY-MM-DD)'

        raise Exception, msg

    if tref=='UTC-3' or tref=='CDT': # chile daylight saving time

        tshft=-3/24.0

    elif tref=='UTC-4' or tref=='CLT': # chile standard time

        tshft=-4/24.0

    else:

        tshft=0.0

    t0=t['value']

    t0 -= tshft

    print "TO = ",t0

    # coaser time (maybe better if called from plotting script for many sources

    #tl = arange(1.,1455.,15) # go over a bit longer than a day

    tl = arange(1.,1455.,1) # go over a bit longer than a day

    tl /=1440.

    tm = t0+tl

    obsMeas = me.observatory(obs)

    me.doframe(obsMeas)

​

    elar=zeros(len(tm))

    azar=zeros(len(tm))

    lastar=zeros(len(tm))

    retutc=zeros(len(tm))

    (ep,ra,dec) = srcCoord.split(" ")[0:3]

​

    #coord = me.direction(ep,ra,dec)

    for i in range(len(tm)):

        t = tm[i]

        tq = qa.quantity(t,'d')