EVN User Experiment Pipeline Feedback
Pipeline feedback for experiment EP042A.
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Last updated: Tue Mar 4 18:08:07 CET 2003
imai@jive.nl
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General Comments.
(
Brief data summary and
scan listing.)
This project consists of 8 telescopes: Wb, Mc, Eb, Jb, Tr, Ur, Sh, Ro (Cm did not observe due to the recorder problem. On did not observe.)
Used 8-MHz 2 bands x 2 pols, with 2-bits sampling. Obtained 2 pairs of polarization (LL, RR). 512 spectral channels per IF. Eb is a reference antenna.
ERI=0.31 (Wb=0.96, Mc=0.63, Eb=0.97, Jb=1.00, Tr=0.98, Ur=0.04, Sh=0.18, Ro=0.23, Cm=0.00, On was excluded. Ro=0.5 if fully successful operation.) ERI*=0.31 (artificial errors only. HA limit of Wb(reduced by 0.04) was taken into account. If excluding On as well, ERI*=0.41).
Plots of the autocorrelations.
Comments.
Wb, Mc, Jb, Tr, Sh : Bright and weak spurs in IF1&2 R&Lpols.
Ur: Low amplitude in IF2 R&Lpols.
Ro: Sometimes a weak spur in IF1 R&Lpols.
Plots of the uncalibrated amplitude and phase against time.
Comments.
Fringe finders and a phase-reference source were well detected with rapid phase variation.
Eb(all telescopes): Phase wrap 00:20-00:25, 02:45-03:10.
Ur: No fringe is found.
Sh, Ro: Fringe is found, but with phase wrap. POSSM_UNCAL Fringe finders were well detected in each of scans with small phase gradients along frequency.
A phase-reference source was marginally detected in each of scans.
Tr: Fringe was not found IF1&2 RR&LL 22:50-22:59.
Ur: No fringe is found.
Sh: Occasionally phase wrap and large phase gradients.
Ro: Occasionally phase wrap.
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.
Wb: Data corrupted in IF2 Rpol and set Tsys=45.9 K.
Mc: High Tsys values 07:10-07:30. IF1&2 Lpol.
Ur: High Tsy values after 05:00.
Ro: Value jumps by about 20 K at the strats of scans (in the original table). They were flagged in the present pipeline.
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.
Wb, Sh: About 120% of that in EVN status table.
Mc, Tr: Roughly consistent with that in EVN status table.
Ef: Difficult to evaluate from the plot. About 120% of that in EVN status table.
Jb: Difficult to evaluate from the plot. Roughly consistent with that in EVN status table.
Ur: About 300% of that in EVN status table.
Ro: About 60% of that in EVN status table.
Fringe-fit phase solutions.
Comments.
Solutions well determined with systematic phase variation.
Eb (reference): Gradual phase slope coming from PA calibration. Solutions lost 02:55-03:10.
Mc: 30% of data produced no solution.
Tr: 95% of solutions were lost.
Ro: 50% of solutions were lost.
Fringe-fit delay solutions.
Comments.
Wb, Jbi, Ro: Offsets within 15 nsec.
Mc: Offsets within 20 nsec.
Tr: Offsets within 30 nsec with systematic variation.
Ur: Offsets of up to -500 nsec.
Sh: Offsets varying from 100 nsec to -50 nsec.
Fringe-fit rate solutions.
Comments.
Rate offsets less than 5 mHz.
Ur: Rate offsets of up to 60 mHz.
Telescope bandpasses.
Comments.
Bandpass amplitudes and phases were well determined.
Ur: Noisy amplitudes and phases.
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.
Mc: Phase wrap in IF4 RR during 04:30-08:30, 10:30-11:00.
Ur: Phase wrap.
Calibrated amplitude and phase against frequency channel.
Comments.
Phase gradient along frequency and phase offsets were well removed.
Eb(all telescopes): Data lost in IF2 LL 03:07-03:10. Occasionally bright spurs.
Mc: Occasionally data lost in IF1 LL.
Ur: Data lost in IF2 LL 02:33-02;41, 05:02-05:11.
Ro: Occasionally data lost in IF1&2.
Phase corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
Comments.
Phase solution well determind in each scan.
Naturally weighted dirty map produced before self-cal of:
3C286.
OQ208.
3C345.
1739+522.
J1509+0545.
Comments.
3C286: No detection due to poor u-v coverage and bright sidelobes up to 2nd contour (4 Jy/beam).
OQ208: Appears over 2nd contour (0.75 Jy/beam).
3C345: Marginally appears over 3rd contour (7.7 Jy/beam).
1739+522: Appears over 3rd contour (0.38 Jy/beam).
J1509+0545: Appears over 2nd contour (0.26 Jy/beam).
Uniformly weighted dirty map produced before self-cal of:
3C286.
OQ208.
3C345.
1739+522.
J1509+0545.
Comments.
3C286: Marginally appears over 3rd contour (5.0 Jy/beam).
OQ208: Appears over 3rd contour (0.70 Jy/beam).
3C345: Appears over 3rd contour (5.5 Jy/beam).
1739+522: Appears over 2nd contour (0.29 Jy/beam).
J1509+0545: Appears over 3rd contour (0.20 Jy/beam).
Amplitude corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
Also available as a text file.
Comments.
Usually gain correction factors smaller than 2.0.
Ur: Large gain correction factors up to 10 in IF2 Rpol for 3C286. No solution from scans of a phase-reference source.
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.
Wb, Mc, Jb, Tr: Roughly consistent with that in EVN status table.
Ef: Difficult to evaluate due to too large SEFD data points. Roughly consistent with that in EVN status table.
Ur: Not available.
Sh: 100-200% of that in EVN status table.
Ro: About 60% of that in EVN status table.
Residual closure phase (visibility closure phase with model closure phase subtracted) for:
3C286.
OQ208.
3C345.
1739+522.
J1509+0545.
Comments.
3C286, OQ208: Systematic closure phase variation was found.
3C345: Deviation from zero closure phase was seen.
1739+522, J1509+0545: Roughly zero closure phase.
Calibrated visibilities and the source model of:
3C286.
OQ208.
3C345.
1739+522.
J1509+0545.
Comments.
3C286, OQ208, 1739+522, J1509+0545: Source models are well consistent with observed amplitudes and phases.
3C345: No comment.
Calibrated visibilities against u,v distance for:
3C286. postscript , png (smaller)
OQ208. postscript , png (smaller)
3C345. postscript , png (smaller)
1739+522. postscript , png (smaller)
J1509+0545. postscript , png (smaller)
Comments.
3C286: 11 Jy at 2M lambda to 0.5 Jy at 45M lambda.
OQ208: 1.7 Jy at 3M lambda to 0.2 Jy at 48M lambda.
3C345: 11 Jy at 3M lambda to 6 Jy at 38M lambda.
1739+522: 0.8 Jy at 3M lambda to 0.07 Jy at 50M lambda.
J1509+0545: Constant at 0.03 Jy.
u,v coverage for:
3C286
postscript, png (smaller)
OQ208
postscript, png (smaller)
3C345
postscript, png (smaller)
1739+522
postscript, png (smaller)
J1509+0545
postscript, png (smaller)
Comments.
3C286: Elongated in the NE-SW direction up to 45M lambda.
OQ208: Elongated in the east-west direction up to 45M lambda.
3C345: Elongated in the NE-SW direction up to 35M lambda.
1739+522: Elongated in the NE-SW direction up to 45M lambda.
J1509+0545: Elongated in the NW-SE direction up to 10M lambda.
Crude map of 3C286 from the pipeline.
Crude map of OQ208 from the pipeline.
Crude map of 3C345 from the pipeline.
Crude map of 1739+522 from the pipeline.
Crude map of J1509+0545 from the pipeline.
Comments.
3C286: An unresolved core and another bright component.
OQ208: A partially resolved core and several side lobes.
3C345: An unresolved core and another bright component with brighter side lobes.
1739+522: An unresolved core and several side lobes.
J1509+0545: A partially resolved core and another component with brighter side lobes.