image_cenA.py

#!/usr/bin/python
# Track target(s) for a specified time.

# The *with* keyword is standard in Python 2.6, but has to be explicitly imported in Python 2.5
from __future__ import with_statement

import optparse
import sys
import uuid

import katuilib
import katpoint
import numpy as np

# Parse command-line options that allow the defaults to be overridden
parser = optparse.OptionParser(usage="%prog [options] <'target'> <'calsource'> [<'calsource'>*]",
                               description="Perform an imaging run of a specified target. A target and one or more cal sources are specified. The mosaic option provides for a three north south scans offset by the HPBW.")
# Generic options
parser.add_option('-i', '--ini_file', dest='ini_file', type="string", metavar='INI', help='Telescope configuration ' +
                  'file to use in conf directory (default reuses existing connection, or falls back to cfg-local.ini)')
parser.add_option('-s', '--selected_config', dest='selected_config', type="string", metavar='SELECTED',
                  help='Selected configuration to use (default reuses existing connection, or falls back to local_ff)')
parser.add_option('-u', '--experiment_id', dest='experiment_id', type="string",
                  help='Experiment ID used to link various parts of experiment together (UUID generated by default)')
parser.add_option('-o', '--observer', dest='observer', type="string",
                  help='Name of person doing the observation (**required**)')
parser.add_option('-d', '--description', dest='description', type="string", default="Target track",
                  help='Description of observation (default="%default")')
parser.add_option('-a', '--ants', dest='ants', type="string", metavar='ANTS',
                  help="Comma-separated list of antennas to include (e.g. 'ant1,ant2')," +
                       " or 'all' for all antennas (**required** - safety reasons)")
parser.add_option('-f', '--centre_freq', dest='centre_freq', type="float", default=1822.0,
                  help='Centre frequency, in MHz (default="%default")')
parser.add_option('-w', '--discard_slews', dest='record_slews', action="store_false", default=True,
                  help='Do not record all the time, i.e. pause while antennas are slewing to the next target')
# Experiment-specific options
parser.add_option('-t', '--track_duration', dest='track_duration', type="int", default=60*15,
                  help='Length of time to track each segment of the mosaic, in integer secs (default="%default")')
parser.add_option('-c', '--cal_duration', dest='cal_duration', type='int', default=60*3, help='Length of time to spend on the cal source (default="%default")')
parser.add_option('-m', '--mosaic', dest='mosaic', action="store_true", default=False, help='Do a 3 pixel N/S mosaic. Only really useful for CenA')

(opts, args) = parser.parse_args()

if len(args) < 2:
    print "Please specify at least a target and a cal source"
    sys.exit(1)
# Various non-optional options...
if opts.ants is None:
    print 'Please specify the antennas to use via -a option (yes, this is a non-optional option...)'
    sys.exit(1)
if opts.observer is None:
    print 'Please specify the observer name via -o option (yes, this is a non-optional option...)'
    sys.exit(1)
if opts.experiment_id is None:
    # Generate unique string via RFC 4122 version 1
    opts.experiment_id = str(uuid.uuid1())
# Try to build the given KAT configuration (which might be None, in which case try to reuse latest active connection)
# This connects to all the proxies and devices and queries their commands and sensors
try:
    kat = katuilib.tbuild(opts.ini_file, opts.selected_config)
# Fall back to *local* configuration to prevent inadvertent use of the real hardware
except ValueError:
    kat = katuilib.tbuild('cfg-local.ini', 'local_ff')
print "\nUsing KAT connection with configuration: %s\n" % (kat.get_config(),)

targets = []
for arg in args:
    # With no comma in the target string, assume it's the name of a target to be looked up in the standard catalogue
    if arg.find(',') < 0:
        target = kat.sources[arg]
        if target is None:
            print "Unknown source '%s', skipping it" % (arg,)
        else:
            targets.append(target)
    else:
        # Assume the argument is a target description string
        targets.append(katpoint.Target(arg, antenna=kat.sources.antenna))
if len(targets) != len(args):
    print "Failed to find all targets specified."
    sys.exit(1)

tgt = targets[0]
calibrators = targets[1:]
print "Target is",tgt.description
print "Calibrator(s) are",calibrators

hpbw_r = tgt.antenna.beamwidth * katpoint.lightspeed / (opts.centre_freq * 1e6) / 12 / 2
 # half power beam width in radians
tgts = []
if opts.mosaic:
    (ra, dec) = tgt.radec()
    print "Mosaic declinations are:",dec-hpbw_r,",",float(dec),",",dec+hpbw_r
    tgts.append(katpoint.construct_radec_target(ra, dec-hpbw_r))
    tgts.append(katpoint.construct_radec_target(ra, dec))
    tgts.append(katpoint.construct_radec_target(ra, dec+hpbw_r))
else:
    tgts.append(tgt)

# Create a data capturing session with the selected sub-array of antennas
with katuilib.start_session(kat, **vars(opts)) as session:
    session.standard_setup(**vars(opts))
    session.capture_start()

    while tgt.azel()[1] > 0.57/2.0:
         # observe the calibrator(s)
        for cal in [x for x in calibrators if x.azel()[1] > 0.57/2.0]:
            print "Observing calibrator"
            session.track(cal, duration=opts.cal_duration, drive_strategy='longest-track', label='cal_source')
            session.fire_noise_diode('coupler')
         # observe the target(s)
        print "Doing track(s)"
        for target in tgts:
            # Track target
            session.track(target, duration=opts.track_duration, drive_strategy='longest-track', label='track')
            # Fire noise diode, to allow gain calibration
            session.fire_noise_diode('coupler')
    print "Session ended with tgt el",tgt.azel()[1],"and cal el",[x.azel()[1] for x in calibrators]