EVN User Experiment Pipeline Feedback
Pipeline feedback for experiment EG026.
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address below.
Last updated: Thu Mar 13 12:15:59 CET 2003
imai@jive.nl
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General Comments.
(
Brief data summary and
scan listing.)
This project consists of 10 telescopes: Cm, Eb, Jb, Mc, Nt, On, Sh, Tr, Wb, Ur. Cm has IF4&5 data avaliable because of the limited bandwidth of the receiver. Sh and Wb were out of antenna operation limit in some time ranges. Jb was excluded in the data because of no fringe.
Used 8-MHz 8 bands x 1 pols (LL), with 1-bits sampling. 16 spectral channels per IF. Eb is a reference antenna.
ERI=0.59 (Cm=0.25, Eb=1.00, Jb=0.00, Mc=1.00, Nt=1.00, On=0.98, Sh=0.43, Tr=0.87, Wb=0.82, Ur=0.47. Taking into account antenna operation limit and bandwidth limit, then assuming Cm=0.25, Wb=0.82, Sh=0.76, Ur=0.89 in fully successful operation. Nt would be operated worse than reported here.) ERI*=0.59 (artificial errors only).
Plots of the autocorrelations.
Comments.
Eb: Ripples in IF7&8.
Mc: Ripples in IF6&8.
Nt: Data lost in 14:37-14:59. A bright spur in IF2.
On: A bright spur and ripples in IF6.
Tr: Ripples in IF2&7.
Wb: A bright peak at the band center of all IFs.
Ur: A ripple in IF7 21:21-21:44.
Plots of the uncalibrated amplitude and phase against time.
Comments.
All of pipelined source were well detected with rapid phase variation.
Eb(all telescopes): Phase wrap 15:10-15:30.
Cm: Finges detected in IF4&5.
Ur, Sh: Phase wrap due to rapid phase rotation.
Tr: No fringe found in IF7. POSSM_UNCAL All of pipelined source were well detected in each of scans with small phase gradients along frequency.
Eb(all telescoopes): No fringe found 15:20-15:34.
Cm: Too bright amplitudes due to the radio link at the band edge of IF4.
Ur: Data IF4,7&8 were lost.
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.
Cm: No Tsys data available. Set Tsys=1.0 K.
Sh: Tsys rapidly increased at 18:40 because of the source close to the horizon.
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.
Cm: Set to SEFD=136 Jy as shown in EVN status table.
Eb, Nt, Tr: Roughly consistent with that in EVN status table.
Mc: 130-200% of that in EVN status table.
On: About 200% of that in EVN status table.
Sh: About 80% of that in EVN status table.
Wb: About 120% of that in EVN status table.
Ur About 250% of that in EVN status table.
Fringe-fit phase solutions.
Comments.
Solutions determined with systematic phase variation.
Cm, Sh, Ur: Phase wrap.
Fringe-fit delay solutions.
Comments.
Cm: Offsets within 20 nsec in IF4. A mean offset of -15 nsec in IF5.
Mc: Mean offsets of around -25 nsec in IF3,5-8.
Nt: Offsets within 20 nsec.
On: Offsets within 10 nsec in IF1-4. Mean offset of -15 nsec in IF5-8.
Sh: Offsets between -30 and -10 nsec.
Tr: Offsets within 10 nsec.
Wb: Offsets within 15 nsec.
Ur: A systematic offset variation by 40 nsec.
Fringe-fit rate solutions.
Comments.
Rate offsets usually less than 2 mHz.
Ur: A mean rate offset of about -7 mHz.
Telescope bandpasses.
Comments.
Bandpass characteristics were well determined in 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. But sometimes phase wrap still remains.
Eb (all telescopes): Phase wrap 15:20-15:35.
Cm: Still phase wrap. Nt: Phase wrap 21:50-22:05.
On: Phase wrap 15:00-15:15.
Calibrated amplitude and phase against frequency channel.
Comments.
Phase gradient along frequency and phase offsets were well removed.
On: Sometimes small phase offsets still remain.
Sh, Ur: Occasionally phase offsets still appeared.
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:
OQ208.
3C286.
Comments.
3C286: A fringe pattern appears over 2nd contour (1.0 Jy/beam).
OQ208: Marginally appears over 3rd contour (1.8 Jy/beam).
The target sources: Well detected over 2nd contour.
Uniformly weighted dirty map produced before self-cal of:
OQ208.
3C286.
Comments.
3C286: Marginally appears over 3rd contour (0.67 Jy/beam).
OQ208: Well detected over 2nd contour (1.1 Jy/beam).
The target sources: Well detected over 3rd or 4th contour.
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 1.3.
Cm, Ur: Occasionally large gain correction factors over 2.
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.
Cm: About 200% of that in EVN status table.
Eb, Nt, Tr, Wb: Roughly consistent with that in EVN status table.
Mc: 100-140% of that in EVN status table.
On: About 150% of that in EVN status table.
Sh: About 70% of that in EVN status table.
Ur About 200% of that in EVN status table.
Residual closure phase (visibility closure phase with model closure phase subtracted) for:
OQ208.
3C286.
Comments.
3C286, OQ208: Closure phases up to 100 degrees.
The target sources: Roughly zero closure phases.
Calibrated visibilities and the source model of:
OQ208.
3C286.
Comments.
All sources: Source models are well consistent with observed amplitudes and phases.
Calibrated visibilities against u,v distance for:
OQ208. postscript , png (smaller)
3C286. postscript , png (smaller)
Comments.
3C286: About 5 Jy at 5M lambda, about 2 Jy at 60M lambda.
OQ208: About 2.5 Jy at 10M lambda, 0.8 Jy at 140M lambda.
The target sources: Detected up to 150M lambda with roughly costant flux densities.
u,v coverage for:
OQ208
postscript, png (smaller)
3C286
postscript, png (smaller)
Comments.
3C286: Elongated in the NW-SE direciton up to 55M lambda.
OQ208: Elongated in the east-west direction up to 140M lambda.
The target sources: Elongated in the east-west op NE-SW direction up to 150M lambda.
Crude map of OQ208 from the pipeline.
Crude map of 3C286 from the pipeline.
Comments.
3C286: An unresolved core.
OQ208: An unresolved core and another component with many side lobes.
The target sources: No comment here.