EVN User Experiment Pipeline Feedback


Pipeline feedback for experiment GS021A. If you have any comments on this experiment please email the address below.
A detailed description of the pipeline output is available.

Last updated: Wed Oct 6 11:07:37 CEST 2004 biggs@jive.nl

General Comments. ( Brief data summary and scan listing )
This is a Global VLBI imaging experiment at 6cm (dual polarisation, 2 IFs). Particpating EVN stations were Ef, Jb, Mc, Nt, Tr, Wb and On. The reference antenna for calibration and plotting was Ef. The EVN reliability indicator was ERI=0.97 (Ef=0.98, Jb=0.96, Mc=0.97, Nt=0.98, Tr=1.00, Wb=1.00, On=1.00). ERI gives you an estimate of the ratio of observed/good visibilities to the expected number. ERI* is the same, but excludes data lost due to circumstances out of the EVN's control e.g. bad weather (ERI*=0.97).

Plots of the autocorrelations .
Comments.
Sc: 20% spike in IF1 (RCP).

Plots of the uncalibrated amplitude and phase against time .
Comments.
Ef: Latter part of first scan (4C39.25) dead.

Plots of the uncalibrated amplitude and phase against frequency channel .
Comments.
None.

The uncalibrated amplitude and phase of the crosshand correlations against frequency channel (not available) .
Comments.
n/a.

TSYS against time .
Comments.
Tr: IF1L looks suspiciously different to the other three.
Sc, Hn, Nl, Br: weather probably affecting values.

Telescope sensitivities from the a priori TSYS and Gain curves (the square of this number gives the antenna noise (SEFD) in Jy - the smaller the better).
Comments.
Most telescopes have predicted sensitivity as given in the EVN Status Table).
Tr: Sensitivity of RCP is a factor of four less than it should be (DPFU value in antab file is four times too small).
Wb: Should be more sensitive (SEFD is 90 instead of 60).

Fringe-fit phase solutions (including Parallactic Angle correction).
Comments.
Ef: variation reflects parallactic angle.

Fringe-fit delay solutions .
Comments.
VLBA: Solutions have only been found for 4C39.25 and J1740+5211. There is essentially no calibrated VLBA data for J1317+4115.

Fringe-fit rate solutions .
Comments.
None.

Telescope bandpasses .
Comments.
All three calibrators were necessary to determine bandpasses for all telescopes due to missing scans. Mc, for example, has no data for either 4C39.25 or J1740+5211.

Calibrated amplitude and phase against time (a priori amplitude calibration and fringe-fit solutions applied).
Comments.
A smattering of data from the VLBA has crept in for J1317+4115.

Calibrated amplitude and phase against frequency channel .
Comments.
Tr: Note much higher amplitudes in RCP.

Naturally weighted dirty map produced before self-cal of:
4C39.25: postscript , or FITS .
J1317+4115: postscript , or FITS .
J1740+5211: postscript , or FITS .
Comments.
None.

Uniformly weighted dirty map produced before self-cal of:
4C39.25: postscript , or FITS .
J1317+4115: postscript , or FITS .
J1740+5211: postscript , or FITS .
Comments.
None.

Phase corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
4C39.25.
J1317+4115.
J1740+5211.
Comments.
None.

Amplitude corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
4C39.25: postscript , or text file .
J1317+4115: postscript , or text file .
J1740+5211: postscript , or text file .
Comments.
In general, the amplitude calibration seems to have been good.
Tr: Incorrect amplitude calibration in RCP is corrected. LCP corrections are also significant.

Telescope sensitivities (the total AMP gain applied during both a priori and self calibration; the square of this number gives the antenna noise (SEFD) in Jy).
Comments.
Ef: Remaining bad data on 4C39.25 is probably responsible for the spike in this plot.
VLBA: Recall that only gain solutions on the two bright sources were reliable.

Residual closure phase (visibility closure phase with model closure phase subtracted) for:
4C39.25 .
J1317+4115 .
J1740+5211 .
Comments.
4C39.25: All triangles including Ef show bad data.
J1317+4115: EVN triangles generally look very nice. J1740+5211: Hn triangles show bad data.

Calibrated visibilities and the source model of:
4C39.25 .
J1317+4115 .
J1740+5211 .
Comments.
4C39.25: Flag this data!
J1740+5211: Hn bad data is obvious.

Calibrated visibilities against u,v distance for:
4C39.25. postscript , or png (smaller)
J1317+4115. postscript , or png (smaller)
J1740+5211. postscript , or png (smaller)
Comments.
None.

u,v coverage for:
4C39.25. postscript , or png (smaller)
J1317+4115. postscript , or png (smaller)
J1740+5211. postscript , or png (smaller)
Comments.
None.

4C39.25: postscript , or FITS .
J1317+4115: postscript , or FITS .
J1740+5211: postscript , or FITS .
Comments.
Source is detected at the centre of each map. J0154+4743 in particular may have a second component.