EVN User Experiment Pipeline Feedback
Pipeline feedback for experiment GV016_3.
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Last updated: Tue Apr 15 14:07:15 CEST 2003
imai@jive.nl
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General Comments.
(
Brief data summary and
scan listing.)
This project consists of 14 telescopes: Eb, Cm, Mc, Wb, Gb, Y27 and 8 VLBA telescopes. Jb, Tr, Hn and Kp did not observe.
There are three passes, 1st for 1720-MHz OH line (IF2 R&Lpols), 2nd for 1665/1667-MHz OH lines (IF1 Lpol) and 3rd for 1665/1667-MHz OH lines (IF1 Rpol). This page is for the 3rd pass.
The 3rd pass consists of 14 telescopes available. Used 8-MHz 1 bands x 1 pols (RR), with 2-bits sampling in 4-sec integration. 512 spectral channels per IF.
Gb is a reference antenna.
ERI=0.38 (Eb=1.00, Cm=1.00, Mc=0.90, Wb=1.00, Jb=0.00, Tr=0.00). ERI*=0.38 (artificial errors only). Global VLBI reliable index~0.62.
Plots of the autocorrelations.
Comments.
Cm, Tr, Gb: A spur.
Jb: Several spurs.
Mc: RFIs around the band center.
Sc, Yy: Sometimes a couple of spurs.
Wb, La, Sc, Pt, Br: A bright spur.
Plots of the uncalibrated amplitude and phase against time.
Comments.
Calibrators were detected with large phase drifts.
Jb, Tr: No fringe was found.
Mc: No fringe during 16:30-18:00.
Fd: Phase wrap 02:40-03:40.
Mk: Phase wrap.
Plots of the uncalibrated amplitude and phase against frequency
channel.
Comments.
Calibrators were well detected in each of scans with phase gradients along frequency.
Jb, Tr: No fringe.
Mc: Fringe was not found 16:32-17:16.
Ov, Br, Mk: Occasionally phase wrap.
The uncalibrated amplitude and phase of the crosshand
correlations against frequency channel.
Comments.
No data.
TSYS against time.
Comments.
Cm: Sparse data points. Tsys values not available, set to Tsys=1 K.
Jb: Sparse data points.
Yy: Ta/Tsys value input.
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 180% of that in EVN status table.
Cm, Mc, Wb: Roughly consistent with that in EVN status table.
Gb: SEFD=9-25 Jy.
VLBA tels: SEFD=250-400 Jy.
Yy: SEFD~16 Jy.
Fringe-fit phase solutions.
Comments.
Mc: Solutions lost 15:30-16;30 in RR&LL.
Fd, Mk: Rapid phase variation.
Fringe-fit delay solutions.
Comments.
Eb, Wb: Offsets systematically varied from -30 nsec to 0 nsec.
Cm: Offsets systematically varied from 10 nsec to 40 nsec.
Wb: Offsets systematically varied from -30 nsec to 0 nsec.
Sc, Nl, La, Pt, Br, Yy: Offsets within 20 nsec.
Fd: Offsets systematically varied from 0 nsec to 200 nsec.
Mk: Offsets systematically varied from 40 nsec to 120 nsec.
Yy: Offsets systematically varied from 20 nsec to 35 nsec.
Fringe-fit rate solutions.
Comments.
Rate offsets within 5 mHz.
Mc: Large rate offsets 16:30-18:00.
Mk: Rate offsets up to 10 mHz 23:30-03:30.
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. Occasionally large phase offsets and wrap still remain.
Mc: No fringe 16:30-17:50.
Calibrated amplitude and phase against frequency channel.
Comments.
Phase gradients along frequency were removed. Occasionally phase offsets.
Mc: Phase wrap 16:54-17:42.
Phase corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
Comments.
Phase solutions determind in each scan of the calibrators.
Mk: Solutions lost 00:30-01:00.
Yy: Solutions lost 23:30-23:40.
Naturally weighted dirty map produced before self-cal of:
3C454.3.
3C84.
DA193.
Comments.
3C454.3: Only fringe pattern above 2nd contour (2.6 Jy/beam) due to poor u-v coverage.
3C84: Marginally detected above 2rd contour (2.9 Jy/beam).
DA193: Only fringe pattern above ??? contour (??? Jy/beam) due to poor u-v coverage.
Uniformly weighted dirty map produced before self-cal of:
3C454.3.
3C84.
DA193.
Comments.
3C454.3: Marginally detected above ??? contour (??? Jy/beam).
3C84: Appears over 3rd contour (4.0 Jy/beam).
DA193: Marginally detected above ??? contour (??? 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.
Sc, Mk: Occasionally too high gain correction factors.
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: 100%-300% of that in EVN status table.
Cm, Wb: Roughly consistent that in EVN status table.
Mc: Difficult to evaluate sensitivity due to too high gain values contaminating.
Gb: SEFD~10 Jy.
VLBA tels: SEFD=200-400 Jy.
Residual closure phase (visibility closure phase with model closure phase subtracted) for:
3C454.3.
3C84.
DA193.
Comments.
Only plots are prepared below this point. See comments in detail in the page for the 1st pass.
Calibrated visibilities and the source model of:
3C454.3.
3C84.
DA193.
Comments.
Calibrated visibilities against u,v distance for:
3C454.3. postscript , png (smaller)
3C84. postscript , png (smaller)
DA193. postscript , png (smaller)
Comments.
u,v coverage for:
3C454.3
postscript, png (smaller)
3C84
postscript, png (smaller)
DA193
postscript, png (smaller)
Comments.
Crude map of 3C454.3 from the pipeline.
Crude map of 3C84 from the pipeline.
Crude map of DA193 from the pipeline.
Comments.