def get_phs_center(msfile):
""" get the phase center of the MS file using CASA taskinit.ms
Parameters
----------
msfile: str
measurement set filename
Returns
-------
pcd:
phase center
Note
----
may need further modification if nField > 1 unless it is the same for all fields (need further investigation)
"""
from taskinit import ms
ms.open(msfile)
pc = ms.getfielddirmeas()
if not isinstance(pc, dict) is True:
pc()
epoch = pc['refer']
pcd_dec = pc['m1']['value'] * 180 / np.pi
pcd_ra = pc['m0']['value'] * 180 / np.pi
if pcd_ra < 0:
pcd_ra += 360
ms.done()
pcd = [pcd_ra, pcd_dec]
return pcd
def MSpcd2(msFile):
"""using CASA taskinit.ms
Parameters
----------
msFile: string
measurement set filename
Returns
-------
pcd:
phase center
Note
----
may need further modification if nField > 1
unless it is the same for all fields
(need further investigation)
"""
from taskinit import ms
ms.open(msFile)
pc = ms.getfielddirmeas()
if not isinstance(pc, dict) is True:
pc()
epoch = pc['refer']
pcd_dec = pc['m1']['value'] * 180 / numpy.pi
pcd_ra = pc['m0']['value'] * 180 / numpy.pi
if pcd_ra < 0:
pcd_ra += 360
ms.done()
pcd = [pcd_ra, pcd_dec]
return pcd
def read_msinfo(vis=None, msinfofile=None):
# read MS information #
msinfo = dict.fromkeys(['vis', 'scans', 'fieldids', 'btimes', 'btimestr', \
'inttimes', 'ras', 'decs'])
ms.open(vis)
scans = ms.getscansummary()
scanids = sorted(scans.keys(), key=lambda x: int(x))
nscanid = len(scanids)
btimes = []
btimestr = []
etimes = []
fieldids = []
inttimes = []
dirs = []
ras = []
decs = []
for i in range(nscanid):
btimes.append(scans[scanids[i]]['0']['BeginTime'])
etimes.append(scans[scanids[i]]['0']['EndTime'])
fieldid = scans[scanids[i]]['0']['FieldId']
fieldids.append(fieldid)
dir = ms.getfielddirmeas('PHASE_DIR', fieldid)
dirs.append(dir)
ras.append(dir['m0'])
decs.append(dir['m1'])
inttimes.append(scans[scanids[i]]['0']['IntegrationTime'])
ms.close()
btimestr = [qa.time(qa.quantity(btimes[i], 'd'), form='fits', prec=10)[0] \
for i in range(nscanid)]
msinfo['vis'] = vis
msinfo['scans'] = scans
msinfo['fieldids'] = fieldids
msinfo['btimes'] = btimes
msinfo['btimestr'] = btimestr
msinfo['inttimes'] = inttimes
msinfo['ras'] = ras
msinfo['decs'] = decs
if msinfofile:
np.savez(msinfofile, vis=vis, scans=scans, fieldids=fieldids, \
btimes=btimes, btimestr=btimestr, inttimes=inttimes, \
ras=ras, decs=decs)
return msinfo
def read_msinfo(vis=None, msinfofile=None, use_scan_time=True):
import glob
# read MS information #
msinfo = dict.fromkeys([
'vis', 'scans', 'fieldids', 'btimes', 'btimestr', 'inttimes', 'ras',
'decs', 'observatory'
])
ms.open(vis)
metadata = ms.metadata()
observatory = metadata.observatorynames()[0]
scans = ms.getscansummary()
scanids = sorted(scans.keys(), key=lambda x: int(x))
nscanid = len(scanids)
btimes = []
btimestr = []
etimes = []
fieldids = []
inttimes = []
dirs = []
ras = []
decs = []
ephem_file = glob.glob(vis + '/FIELD/EPHEM*SUN.tab')
if ephem_file:
print('Loading ephemeris info from {}'.format(ephem_file[0]))
tb.open(ephem_file[0])
col_ra = tb.getcol('RA')
col_dec = tb.getcol('DEC')
col_mjd = tb.getcol('MJD')
if use_scan_time:
from scipy.interpolate import interp1d
f_ra = interp1d(col_mjd, col_ra)
f_dec = interp1d(col_mjd, col_dec)
for idx, scanid in enumerate(scanids):
btimes.append(scans[scanid]['0']['BeginTime'])
etimes.append(scans[scanid]['0']['EndTime'])
fieldid = scans[scanid]['0']['FieldId']
fieldids.append(fieldid)
inttimes.append(scans[scanid]['0']['IntegrationTime'])
ras = f_ra(np.array(btimes))
decs = f_dec(np.array(btimes))
ras = qa.convert(qa.quantity(ras, 'deg'), 'rad')
decs = qa.convert(qa.quantity(decs, 'deg'), 'rad')
else:
ras = qa.convert(qa.quantity(col_ra, 'deg'), 'rad')
decs = qa.convert(qa.quantity(col_dec, 'deg'), 'rad')
else:
for idx, scanid in enumerate(scanids):
btimes.append(scans[scanid]['0']['BeginTime'])
etimes.append(scans[scanid]['0']['EndTime'])
fieldid = scans[scanid]['0']['FieldId']
fieldids.append(fieldid)
inttimes.append(scans[scanid]['0']['IntegrationTime'])
dir = ms.getfielddirmeas('PHASE_DIR', fieldid)
dirs.append(dir)
ras.append(dir['m0'])
decs.append(dir['m1'])
ms.close()
btimestr = [
qa.time(qa.quantity(btimes[idx], 'd'), form='fits', prec=10)[0]
for idx in range(nscanid)
]
msinfo['vis'] = vis
msinfo['scans'] = scans
msinfo['fieldids'] = fieldids
msinfo['btimes'] = btimes
msinfo['btimestr'] = btimestr
msinfo['inttimes'] = inttimes
msinfo['ras'] = ras
msinfo['decs'] = decs
msinfo['observatory'] = observatory
if msinfofile:
np.savez(msinfofile,
vis=vis,
scans=scans,
fieldids=fieldids,
btimes=btimes,
btimestr=btimestr,
inttimes=inttimes,
ras=ras,
decs=decs,
observatory=observatory)
return msinfo