EVN Network Monitoring Experiment (NME) Pipeline Feedback
Pipeline feedback for experiment N02C1.
If you have any comments on this experiment please email
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address below.
Last updated: Thu Sep 5 14:46:13 WET DST 2002
paragi@jive.nl
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General Comments.
(
Brief data summary and
scan listing.)
Two heads recording, 512 Mbit/s data rate, 64 MHz bandwidth per polarization. Effelsberg is the reference antenna. The main targets were observed in phase-referencing mode (DA193,J0605+0430). Three other sources were observed for checking amplitude calibration (J0612+4122, J0607+4739,J0625+4440), and one was scheduled specially for Arecibo (J2253+1608). Arecibo could not observe eventually; there were no fringes to Jodrell Bank (power shortage) and Urumqi (reason unknown). In Torun BBC7 was known to be bad prior to the observations. Westerbork used 14 BBCs because a single BBC could not record USB+LSB due to bandwidth limitations. Because of the microwave link limitations there were data only in R4-5 and L4-5 for Cambridge. The playback was poor so much of the Cm LCP data were lost.
ERI=ERI*=0.54 (Ef=1, Mc=0.85, Wb=1, On=1, Tr=0.7, Jb=0, Ar=0, Cm=0.5, Nt=0.5, Sh=0.5, Hh=1; N=7.05, Nexp=9.39)
Plots of the autocorrelations.
Comments.
Ef: L8 is probably affected by the well-known dead track (27)
Mc: L6 is low (BBC5 upper sideband)
Wb: L7/R7 missing (14 BBC used)
On: L6 - RFI(?) seen only in LCP
Tr: R5/R7 missing (BBC5 and BBC7 lower sidebands); between 8:50-9:39 UT 2nd headstack did not head peak during correlation
Jb: autocorrelation probably affected by the power supply problem
Cm: data are only in L4-5 & R4-5 because of bandwidth limitations in microwave link; much data were lost due to poor playback, especially in LCP
Ur: L4/R4 dead (BBC3 and BBC4 upper sidebands); 10:45-11:06 - source was not observed; 9:16-9:39 - left out from correlator job (3rd recorrelation of this pass) because did not produce fringes
Sh: only LCP receiver
Nt: did not record headstack 2
Hh: L6 low (BBC5 upper sideband); R2-3 dead (BBC2 upper and BBC4 lower sidebands)
Plots of the uncalibrated amplitude and phase against time.
Comments.
Ef: L8 data look good regardless of the very high parity errors on track 27
Mc: no fringes between 9:25-9:40 UT and near 11:15 UT
Wb: no data in L7 and R7 due to limited number of BBCs
Tr: some 2nd headstack data lost during correlation (Tr could not head peak in all passes); no fringes in R7-8 (BBC7 was dead, known from station feedback)
Jb: no fringes due to power supply problems
Cm: data are in L4-5 & R4-5 (see above); much is lost due to poor playback, especially in LCP
Ur: no fringes, reason unknown
Sh: scan between 10:40-11:00 UT - source below horizon; Sh has only LCP receiver in C-band
Nt: no fringes between ~10:40-11:00 UT
Hh: scan between 10:40-11:00 UT - source below horizon
Plots of the uncalibrated amplitude and phase against frequency
channel.
Comments.
Ef: data look good in L8
Mc: low amplitude in L1-4 and R1-4 between 9:25-9:40 UT (probably due to poor playback on hs1 reverse passes); no fringes at all between 11:12-11:17 UT
Wb: no data in L7 and R7 due to limited number of BBCs
Tr: data from 2nd headstack have low amplitude and high residual delay; no fringes in R7-8 (BBC7 was dead, known from station feedback)
Jb: no fringes due to power supply problems
Cm: data are in L4-5 & R4-5 (see above); much is lost due to poor playback, especially in LCP
Ur: no fringes, reason unknown
Nt: no fringes between ~10:40-11:00 UT
Hh: R3-4 has low amplitude (BBC4 upper and lower sideband)
The uncalibrated amplitude and phase of the crosshand
correlations against frequency channel.
Comments.
Ef: high D-term in L8
Wb: improved performance compared to the FEB02 session, but D-temrs still show a frequency dependence (espacially at the higher frequencies)
TSYS against time.
Comments.
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.
On,Ur: sensitivity is lower than expected (see the EVN Status Tables)
All: Tsys high between 10:40-11:00 UT because the source was at low elevation
Fringe-fit phase solutions.
Comments.
Phase stability looks good at all stations, except at Cm in L4
Fringe-fit delay solutions.
Comments.
Delay residuals are generally low (<30 ns).
Cm: L5 residuals are somewhat higher (40 ns)
Tr: R5-6, L5-8 (2nd headstack data) have high residuals (50-100 ns)
Fringe-fit rate solutions.
Comments.
Telescope bandpasses.
Comments.
Tr: L5-8 (BBC 6 and 8, upper and lower sideband), and R6 (BBC 5 upper sideband) have strange bandpass; problem is probably unrelated to BBCs, see N02L1 Pipeline
All: strange bandpasses in L8 - something went wrong during data processing (compare POSSMs of calibrated and uncalibrated data)
Calibrated amplitude and phase against time
(a priori amplitude calibration and fringe-fit solutions applied).
Comments.
Calibrated amplitude and phase against frequency channel.
Comments.
All: strange bandpasses in L8, see above
Mc: low amplitudes in L1-4 and R1-4 between 9:25-9:40 UT were not corrected
Tr: 2nd headstack low amplitudes were not corrected
Hh: R3-4 low amplitudes were not corrected
Phase corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
Comments.
Amplitude corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
Also available as a text file.
Comments.
Hh: very high corrections in R3-4 (BBC4: ~factor of 7 in Tsys); see comments on low amplitude above
Tr: high corrections (up to a factor of 4 in Tsys) in 2nd headstack channels - except in R5 where correction is low; see notes on bandpass
Cm: very high corrections in L5 and L4 (x4 and x20 in Tsys, respectively) - probably related to poor playback
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.
On: sensitivity is lower than expected from EVN Status Tables (SEFD=600 Jy)
Hh: R3-4 are much less sensitive than expected (see notes above)
Tr: 2nd headstack channels are less sensitive than expected (SEFD=250 Jy) except R5 - see notes on bandpass
Cm: L4 is much less sensitive than expected (SEFD=136 Jy) - see notes on playback above
Residual closure phase (visibility closure phase with
model closure phase subtracted) for DA193.
Residual closure phase (visibility closure phase with
model closure phase subtracted) for J0605+4030.
Comments.
Calibrated visibilities and the source model of
DA193.
Calibrated visibilities and the source model of
J0605+4030.
Comments.
Calibrated visibilities against u,v distance for
DA193.
Calibrated visibilities against u,v distance for
J0605+4030.
Comments.
u,v coverage for
DA193.
u,v coverage for
J0605+4030.
Comments.
Crude map of DA193 from the pipeline.
Crude map of J0605+4030 from the pipeline.
Comments.