EVN User Experiment Pipeline Feedback
Pipeline feedback for experiment EP041B_2.
If you have any comments on this experiment please email
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address below.
Last updated: Tue Mar 25 20:34:50 CET 2003
imai@jive.nl
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General Comments.
(
Brief data summary and
scan listing.)
This project consists of 6 telescopes: Jb, Ef, Mc, On, Tr, Cm. No fring detected in Cm.
There are two passes, 1st for line emission (IF1) 2nd for continuum emission (IF2&3, here equivalent to IF1&2). This page is for the 2nd pass.
Used 2-MHz 2 bands x 2 pols, with 2-bits sampling. Obtained 2 pairs of polarization (LL, RR) in 2-sec integration. 16 spectral channels per IF.
Ef is a reference antenna.
ERI=0.34 (Jb=0.93, Ef=0.99, Mc=0.12, On=0.86, Tr=0.84, Cm=0.00). ERI*=0.35 (Taking into account antenna-pointing at Ef and other stations).
Plots of the autocorrelations.
Comments.
On: A bright ripple at the band center in IF2 R&Lpols.
Plots of the uncalibrated amplitude and phase against time.
Comments.
Fringe finders and a phase-reference source were detected with ocassionally phase wrap.
Mc: Fringe not found in the phase-reference.
Cm: No fringe was found. POSSM_UNCAL Fringe finders were detected in each of scans.
Plots of the uncalibrated amplitude and phase against frequency
channel.
Comments.
The uncalibrated amplitude and phase of the crosshand
correlations against frequency channel.
Comments.
No data.
TSYS against time.
Comments.
Sparse data points except for Ef.
Tr: Tsys data are not available, set to Tsys=1 K.
Cm: Tsys data are not available, set to Tsys=149 K.
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.
Jb, Cm: Too high gain values (check DPFU values).
Ef: 120-150% of that in EVN status table.
Mc: Roughly consistent with that in EVN status table.
On: About 200% of that in EVN status table.
Tr: 60-80% of that in EVN status table.
Fringe-fit phase solutions.
Comments.
Sometimes solutions were lost.
Ef (reference): Phase variation due to PA calibration was found.
Cm: No solution.
Fringe-fit delay solutions.
Comments.
Jb, On, Tr: Offsets within 100 nsec.
Ef (reference): Some parts of solutions were lost because of antenna-pointing, but data themselves still exist.
Fringe-fit rate solutions.
Comments.
Rate offsets within 5 mHz.
Telescope bandpasses.
Comments.
Bandpass amplitudes and phases were well determined.
Calibrated amplitude and phase against time
(a priori amplitude calibration and fringe-fit solutions applied).
Comments.
Large phase drifts were reduced. Sometimes phase wrap still remains.
Calibrated amplitude and phase against frequency channel.
Comments.
Phase gradients along frequency were removed, but phase offsets ocassionally still remain.
Phase corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
Comments.
Phase solutions determind in each scan of the phase-reference. Sometimes solutions were lost.
Naturally weighted dirty map produced before self-cal of:
3C345.
3C454.3.
J1922+1530.
Comments.
3C345: Only fringe pattern above 2nd contour (2.3 Jy/beam) due to poor u-v coverage.
3C454.3: Only fringe pattern above 2nd contour (2.2 Jy/beam) due to poor u-v coverage.
J1922+1530: Appears over 2nd contour (0.11 Jy/beam).
Uniformly weighted dirty map produced before self-cal of:
3C345.
3C454.3.
J1922+1530.
Comments.
3C454.3: Marginally detected above 3rd contour (2.8 Jy/beam).
3C345: Only fringe pattern above 2nd contour (4.2 Jy/beam) due to poor u-v coverage.
J1922+1530: Appears over 4th contour (0.16 Jy/beam).
Amplitude corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
Also available as a text file.
Comments.
Jb: Gain correction factors smaller than 0.06.
Ef, Mc, Tr: Gain correction factors within 1.5, sometimes larger than 3.
On: Gain correction factors 0.4-0.8.
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.
Jb: Varied in 10-100% of that in EVN status table.
Ef: Roughly consistent with that in EVN status table.
Mc: Difficult to evaluate because of too high values contaminating.
On, Tr: Difficult to evaluate because of too high values contaminating. Roughly consistent with that in EVN status table.
Residual closure phase (visibility closure phase with model closure phase subtracted) for:
3C345.
3C454.3.
J1922+1530.
Comments.
3C345, 3C454.3: Systematic closure phase variation was seen.
J1922+1530: Closure phase wrap.
Calibrated visibilities and the source model of:
3C345.
3C454.3.
J1922+1530.
Comments.
Source models are roughly consistent with observed amplitudes and phases.
Calibrated visibilities against u,v distance for:
3C345. postscript , png (smaller)
3C454.3. postscript , png (smaller)
J1922+1530. postscript , png (smaller)
Comments.
3C345: Roughly constant around 7 Jy.
3C454.3: 16 Jy at 16M lambda, 2 Jy at 32M lambda.
J1922+1530: Roughly constant at 200 mJy.
u,v coverage for:
3C345
postscript, png (smaller)
3C454.3
postscript, png (smaller)
J1922+1530
postscript, png (smaller)
Comments.
3C345, 3C454.3: Sparse distribution within 30M lambda.
J1922+1530: Elongated in the east-west direction up to 30M lambda. Also sparse distribution was found in the north-south direction up to 25M lambda.
Crude map of 3C345 from the pipeline.
Crude map of 3C454.3 from the pipeline.
Crude map of J1922+1530 from the pipeline.
Comments.
3C345: Disappeared in the map because of poor (u,v) coverage.
3C454.3: An unresolved core and several side lobes (true components?).
J1922+1530: A partially resolved core plus another component elongated in the north-south direciton, and brighter side lobes.