Troposphere calibrators for VLBA Calibrator Survey observing
sessions
In addition to observing target objects, 3-4 strong sources from the
troposphere calibrator list were observed every 1-1.5 hours during observing
VLBA Calibrator Surveys VCS2, VCS3, VCS4 and VCS5 sessions. They were
scheduled in such a way, that at each VLBA station at least one of these
sources was observed at an elevation angle less than
20o, and at least one at an elevation angle greater
than 50o. The purpose of these observations was
to provide calibration for mismodeled atmospheric path delays and to tie the
VCS source positions to the ICRF catalogue
Ma et al. 1998. The list of troposphere calibrators was selected among
the sources which according to the 2cm survey results
Kovalev et al. 1998 showed the
compactness index, i.e. the ratio of the flux density of an unresolved detail
to the total VLBA flux density, more than 0.5. The coordinates of these
sources are taken from the astrometric and
geodetic catalogue RFC.
The troposphere calibrator list
Catalogue of 155 sources which forms the
pool of tropospheric calibrators.
The same source list
in VLBA SCHED key-file format.
References
-
Ma, C., Arias, E.F., Eubanks, T.M., Fey, A.L., Gontier, A.-M.,
Jacobs, C.S., Sovers, O.J., Archinal, B.A., and Charlot, P.,
1998, The International Celestial Reference Frame as Realized by Very
Long Baseline Interferometry, Astronomical Journal, 116, 516
-
Kovalev, Y.Y., Kellermann, K.I., Lister, M.L.,
Homan, D.C., Vermeulen, R.C., Cohen, M.H., Ros, E.,
Kadler, M., Lobanov, A.P., Zensus, J.A.,
Kardashev, N.S., Gurvits, L.I., Aller, M.F., and Aller, H.D.
2005, Sub-milliarcsecond Imaging of Quasars and Active Galactic Nuclei.
IV. Fine Scale Structure, Astronomical Journal, 130, 2473.
(astro-ph/0505536)
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This page was prepared by Leonid Petrov
(
)
Last update: 2017.06.20_11:15:49