EVN Network Monitoring Experiment (NME) Pipeline Feedback
Pipeline feedback for experiment N02L2.
If you have any comments on this experiment please email
the
address below.
Last updated: Mon Sep 9 11:13:54 CEST 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. Medicina 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 (J2148+0657). There were fringes to all stations. Effelsberg started 1.5 hours late because of problems with the focus, while Hartebeesthoek could join in the observations only in the last half hour (sources were below horizon). 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. In Shanghai the RCP receiver was broken down; Noto recorded only headstack 1.
ERI=ERI*=0.57 (Mc=1, Ef=0.35, Wb=0.85, On=0.85, Tr=0.7, Nt=0.5, Jb=1, Ur=0.7, Hh=0.17, Ar=0.17, Sh=0.5; N=6.79,
Nexp=8.84). Losses at Wb and Jb due to missing Tsys data are not counted (bug fixed in the pipeline script).
Plots of the autocorrelations.
Comments.
Ef: L8 is probably affected by the well-known dead track (27)
Mc: L6 is low (BBC5 upper sideband); RFI in L7-8/R7-8
Wb: L7/R7 missing (14 BBC used)
On: RFI in L2/R2
Tr: R5/R7 missing (BBC5 and BBC7 lower sidebands)
Jb: L3 is low (BBC3 lower sideband); some RFI in L6/R6
Ur: L4/R4 is low (BBC3 and BBC4 upper sidebands)
Sh: RCP receiver was broken down (known from station feedback); RFI in L2
Nt: did not record headstack 2
Hh: L6 low (BBC5 upper sideband); RFI in R3? - seen only in RCP
Plots of the uncalibrated amplitude and phase against time.
Comments.
Ef: started late; L8 data look good
Wb: no data in L7 and R7 due to limited number of BBCs
Tr: no fringes in R7-8 (BBC7 was dead, known from station feedback)
Ur: R5-8 seem to have problems (2nd headstack recording?); source not observed between 8:00-8:30 UT
Sh: source not observed between 8:00-8:30 UT; RCP receiver was broken down
Nt: did not record headstack 2
Hh: started after 8:30 UT
Ar: observed only the scan between 8:00-8:30 UT
Plots of the uncalibrated amplitude and phase against frequency
channel.
Comments.
Ef: started late; data look good in L8
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: L3 low (see above)
Ur: L4/R4 low (see above); much 2nd headstack data was lost (all in RCP)
Nt: did not record headstack 2
Hh: R3-4 has low amplitude (BBC4 upper and lower sideband), and R3 has a peaked bandpass; L6 is good (c.f. autocorrelations)
The uncalibrated amplitude and phase of the crosshand
correlations against frequency channel.
Comments.
TSYS against time.
Comments.
Jb: channels L3-8 have high Tsys; also some of the Tsys data are missing
Tr: much of the Tsys data are missing in L5-6
Wb: no Tsys data for 2nd headstack channels!
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.
Mc is less sensitive than expected (SEFD=582 Jy, see the EVN Status Tables)
Jb: L3-8 have low sensitivity (SEFD=320 Jy - used Mk2), see notes on high Tsys above
Ar: less sensitive than expected (SEFD=4 Jy)
Fringe-fit phase solutions.
Comments.
Phase stability looks good at all stations
Fringe-fit delay solutions.
Comments.
Delay residuals are generally low (<30 ns).
Ur: R1-4 residuals are high (70-100 ns)
Tr: R5-6, L5-8 (2nd headstack data) have high residuals (70-120 ns)
Hh: high residuals (~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
Wb: 2nd headstack missing because there were no Tsys data available!
Calibrated amplitude and phase against time
(a priori amplitude calibration and fringe-fit solutions applied).
Comments.
Jb, Tr, Wb: some data lost because of missing Tsys (see above)
Calibrated amplitude and phase against frequency channel.
Comments.
Tr: 2nd headstack low amplitudes were not corrected
Jb: L3 still low; L4-8 very high (erronous Tsys data, see above)
Ur: low amplitude in L4 was 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.
Ur: high corrections in L4/R4 (factor of 2-4 in Tsys) - see comments on low amplitude above
Hh: very high corrections in R3-4 (BBC4: ~factor of 6 in Tsys) - low amplitude was noted above
Tr: high corrections (up to a factor of 9 in Tsys) in 2nd headstack channels - except in R5
Jb: corrections are low (factor of 1/2-1/4 in Tsys) in L4-8, while these are high in L3 (x4) - see notes on gain calibration above (POSSM_CAL)
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.
Mc sensitivity is as expected (cf. notes on GAIN above)
Tr: 2nd headstack channels are less sensitive than expected (SEFD=230 Jy) except R5 - see notes above
Jb: L3 have low sensitivity, L4-8 are OK (SEFD=320 Jy - used Mk2), see notes on high Tsys above
Ur: L4/R4 are very insensitive, but other channels seem to be more sensitive than expected (SEFD=1068 Jy, see the EVN Status Tables)
Sh: seems to be more sensitive than expected (SEFD=1088 Jy)
Ar: less sensitive than expected (SEFD=4 Jy)
Hh: R3-4 are very insensitive, but in general the sensitivity seem to be better than expected
General note: imperfect source model on long baselines may cause the apparent high sensitivities at Ur, Sh and Hh
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.