EVN User Experiment Pipeline Feedback
Pipeline feedback for experiment GG045.
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address below.
Last updated: Mon Feb 3 20:59:20 CET 2003
imai@jive.nl
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General Comments.
(
Brief data summary and
scan listing.)
This project consists of 15 telescopes: Eb, Mc, Jb, Wb, Tr, Nt and 9 VLBA telescopes. On did not observe because of strong wind.
Used 8-MHz 2 bands x 2 pols, with 2-bits sampling. Obtained 2 pairs of polarization (LL, RR). 16 spectral channels per IF.
Eb and Hn are 1st and 2nd reference antennas.
ERI=0.68 (Eb=0.92, Mc=1.00, Jb=1.00, Wb=1.00, Tr=0.96, Nt=1.00, On=0.00), ERI*=0.96 (Assuming On=1.00), Global VLBI reliable index=0.58
Plots of the autocorrelations.
Comments.
Plots are available only during 00:00-11:00 when Eb was observing.
Mc, Jb: A wide and bright spur at band center in IF1 R&Lpols.
Wb: A wide and mild spur at band center in IF1 R&Lpols.
Pt: Data lost 05:16-05:38, 06:24-06:46, 08:42-09:28. Occasionally a wide spur in IF1&2 R&Lpols.
Br: Sometimes a wide spur in IF2 R&Lpols.
Plots of the uncalibrated amplitude and phase against time.
Comments.
The firnge finder and phase-reference sources were detected.
Plots are available only during 00:00-11:00 when Eb was observing.
Eb: Phase wrap and lower amplitudes during 08:40-09:30 with the EVN antennas and during 08:40-11:00 with the VLBA antennas.
Pt: Data lost 06:20-07:00, 09:20-10:00. Phase wrap during above time ranges.
Nl, Kp: Data lost 06:20-06:40.
La: Data lost 06:20-07:10.
Ov: Data lost 05:40-06:20.
Plots of the uncalibrated amplitude and phase against frequency
channel.
Comments.
The sources were well detected with larger phase gradient along frequency in longer baseline.
The uncalibrated amplitude and phase of the crosshand
correlations against frequency channel.
Comments.
No data.
TSYS against time.
Comments.
Mc, Jb, Tr, Nt: Sparse data points (interval of 30 min).
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.
Eb: About 150% of that in the EVN status tables.
Mc: Roughly consistent with that in the EVN status tables. Gain factors increase during 05:00-08:00.
Jb: Roughly consistent with that in the EVN status tables.
Wb: Roughly consistent with that in the EVN status tables. Many ripples.
Tr: 150%-500% of that in the EVN status tables.
Nt: 120%-150% of that in the EVN status tables.
VLBA: SEFD=330-400 Jy.
Fringe-fit phase solutions.
Comments.
Solutions well determined.
Eb (reference): Gradual phase slope coming from PA calibration. Solutions lost 08:40-09:30.
Fringe-fit delay solutions.
Comments.
Mc, Jb, Wb, Tr: Offsets within 20 nsec with systematic variation.
Nt: Systematic variation with offsets up to 1000 nsec.
VLBA: Offsets within 60 nsec with systematic variation.
Fringe-fit rate solutions.
Comments.
Mc, Jb, Wb, Tr: Rate offsets within 5 mHz.
Nt: Systematic variation with rate offsets up to Offsets 250 mHz.
VLBA: Rate offsets within 10 mHz.
Telescope bandpasses.
Comments.
Well determined in amp&phase.
Calibrated amplitude and phase against time
(a priori amplitude calibration and fringe-fit solutions applied).
Comments.
Large phase drifts were well reduced. Sometimes phase wrap still remains.
Calibrated amplitude and phase against frequency channel.
Comments.
Phase gradients along phase were well removed.
Nt: Phase offsets still remain.
Phase corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
Comments.
Sometimes solutions lost.
Naturally weighted dirty map produced before self-cal of:
OQ208.
J1453+2648.
Comments.
OQ208: Marginally appears over 3rd contour (8.8 Jy/beam).
J1453+2648: Appears over 3rd contour (0.18 Jy/beam).
Uniformly weighted dirty map produced before self-cal of:
OQ208.
J1453+2648.
Comments.
OQ208: Appears over 3rd contour (8.1 Jy/beam).
J1453+2648: Marginally appears over 3rd contour (0.18 Jy/beam).
Amplitude corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
Also available as a text file.
Comments.
Gain correction factors usually within 1.2. Solutions significantly lost.
Ef: Up to 10.0 around 08:40.
Jb: Up to 4.0 10:10-10:30.
Nt: Up to 5.0 07:00-08:30.
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.
Eb, Jb, Wb, Tr: Difficult to evaluate because of some data points with too high gain factors. Roughly consistent with that in the EVN status tables.
Mc: 100%-200% of that in the EVN status tables.
Nt: 50%-2000% of that in the EVN status tables.
VLBA: Difficult to evaluate because of some data points with too high gain factors. SEFD~150-250 Jy.
Residual closure phase (visibility closure phase with model closure phase subtracted) for:
OQ208.
J1453+2648.
Comments.
OQ208: Closure phases close to zero.
J1453+2648: Closure phases systematically and significantly vary.
Calibrated visibilities and the source model of:
OQ208.
J1453+2648.
Comments.
OQ208: A point-source model is roughly consistent to the observed amp&phases.
J1453+2648: Inconsistent with observed amp&phases.
Calibrated visibilities against u,v distance for:
OQ208. postscript , png (smaller)
J1453+2648. postscript , png (smaller)
Comments.
OQ208: About 1.2 Jy at 1M lambda, about 0.8 Jy at 31M lambda.
J1453+2648: Difficult to evaluate because of some abnormally-high flux deinsity points. Less than 2 Jy.
u,v coverage for:
OQ208
postscript, png (smaller)
J1453+2648
postscript, png (smaller)
Comments.
OQ208: Elongated in the east-west direction up to 30M lambda.
J1453+2648: Elongated in the east-west direction up to 55M lambda.
Crude map of OQ208 from the pipeline.
Crude map of J1453+2648 from the pipeline.
Comments.
OQ208: An unresolved component.
J1453+2648: An unresolved component and sidelobes. A too sharply elongated synthesized beam.