EVN User Experiment Pipeline Feedback


Pipeline feedback for experiment ER025A. If you have any comments on this experiment please email the address below.
A detailed description of the pipeline output is available.

Last updated: Thu Jan 13 20:08:01 CET 2011 muehle@jive.nl

General Comments. ( Brief data summary and scan listing )
K band (22 GHz) spectral line EVN experiment, observed on 29/30 October 2010. The data rate was 512 Mbps (4 x 16 MHz subbands, dual polarization, two-bit sampling). The target source 'ARP299A' was calibrated using the phase-reference sources 'J1128+5925'. The calibrator source '4C39.25' was used as fringe finder. In this pipeline reduction, Ef, Mc and On served as reference antennas and On as plot reference, i.e. the plots show baselines to On.
7 stations participated in the experiment: Ef, Jb, On, Mc, Mh, Ro and Ys. Ef reported that a few bits may have been lost in scans #450 and #458. Between 07:39 UT and 09:16 UT, when the source elevation at Ef was 80 degrees or more, the telescope monitoring log indicates that the antenna was not on source. Therefore this time range has been flagged in the Ef data. At Mc, VC02 (= IF1/R) lost its lock at times. At Mh, BBC01 (= IF1/R) is suspected to be broken and BBC02 (= IF1/L) did not lock to the requested low frequency. As a consequence, IF1 of Mh has been flagged for the entire experiment before the pipeline was run. The RCP channels of Jb have very low amplitudes and bad phases, so that they were flagged for the entire experiment as well. The noise diode at Ro did not work properly. Instead, zenith calibration and an ambient load were used for the calibration.

The EVN reliability indicator (ERI) for this experiment was ERI = 0.78 . ERI* = 0.78 . (EF=1, JB=0.5, ON=1, MC=1, MH=0.75, RO=1, YS=1)

Plots of the autocorrelations
Comments.
in general, bandpasses seem to be stable; Jb: a few strong RFI spikes, especially in IF2/L and IF3/L; occasionally, low-level RFI spikes at other stations as well; Ro: wiggely bandpasses in LCP, but stable; On: a few scans between 00:48 and 02:05 UT flagged; Ef: data between 07:39 UT and 09:16 UT flagged (high source elevation); 932 pages

plots of the uncalibrated amplitude and phase against time
Comments.
not unexpectedly, fast phase rotation seen on all baselines; in general, phases of the fringe finder can be followed easily; On: a few scans between 00:48 and 02:05 UT flagged; Ef: data between 07:39 UT and 09:16 UT flagged; Mh: IF1/L+R flagged (see above); Jb: RCP channels flagged (see above); 15 pages

Plots of the uncalibrated amplitude and phase against frequency channel
Comments.
except for the glitches already mentioned, bandpasses seem to be stable; Jb: RFI spikes mentioned above show up in baselines; even uncalibrated, phases of the fringe finder can easily be followed on all baselines, except for Jb at 04:01 - 04:11 UT (bad bandpasses and phases) and Mc/IF1/R at 08:05 - 08:15 UT; 690 pages

The uncalibrated amplitude and phase of the crosshand correlations against frequency channel (not available)
Comments.

TSYS against time
Comments.
Jb: no Tcal information available; rest of T_sys looks reasonable; On: note that Tsys includes the atmosphere (chopper-wheel calibration), wheather improved after 04 UT; 6 pages

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.
mimic curves of Tsys; 6 pages

Fringe-fit phase solutions (including Parallactic Angle correction).
Comments.
refant = Ef, drift in phases reflects the parallactic angle correction; generally fast fringe rates; few solutions outside of fringe finder scans for Mh and Ro; 5 pages

Fringe-fit delay solutions
Comments.
refant = Ef; delays of the order of (a few tens of) nanoseconds; a few outliers; 5 pages

Fringe-fit rate solutions
Comments.
refant = Ef; rates of the order of mHz; some outliers; 5 pages

Telescope bandpasses
Comments.
refant = Ef; in general, amplitudes close to 1.0 and phases close to zero, except at the edges of the bandpasses; Mh: prominent kink in bandpass and large phases in IF4/R; Ro: bandpasses and phases a bit noisier than at other stations; 2 pages

Calibrated amplitude and phase against time (a priori amplitude calibration and fringe-fit solutions applied).
Comments.
for the fringe finder, phases aligned close to zero, although rather noisy at Jb and Ro, and amplitudes seem to be stable; 15 pages

Calibrated amplitude and phase against frequency channel
Comments.
amplitudes and phases of the fringe finder look ok; 149 pages

Naturally weighted dirty map (not useful for bright sources) produced before self-cal of:
ARP299A: pdf , or FITS .
J1128+5925: pdf (not available) , or FITS (not available) .
4C39.25: pdf (not available) , or FITS (not available) .
Comments.

Uniformly weighted dirty map (not useful for bright sources) produced before self-cal of:
ARP299A: pdf , or FITS .
J1128+5925: pdf (not available) , or FITS (not available) .
4C39.25: pdf (not available) , or FITS (not available) .
Comments.

Phase corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
ARP299A (not available) .
J1128+5925 .
4C39.25 .
Comments.
refant = Ef; small phase corrections for the fringe finder (< 20 deg), significantly larger for the phase-reference source; 5 pages per source

Amplitude corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
ARP299A: pdf (not available) , or text file (not available) , or statistical summary (not available) .
J1128+5925: pdf , or text file , or statistical summary .
4C39.25: pdf , or text file , or statistical summary .
Comments.
corrections look reasonable, a few outliers; Jb, Mh, Ro: few solutions found for phase-reference source; large values for Jb (no Tcal information available) and Ro (few solutions); 5 pages per 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.
sensitivities look generally reasonable; Ro: few solutions, large scatter; 5 pages

Residual closure phase (visibility closure phase with model closure phase subtracted) for:
ARP299A (not available) .
J1128+5925 .
4C39.25 .
Comments.
residual closure phases generally clustered around a small value for the fringe finder; very few solutions for the phase-reference source; 7 pages for fringe finder, 1 page for the phase-reference source

Calibrated visibilities and the source model of:
ARP299A (not available) .
J1128+5925 .
4C39.25 .
Comments.
in general, very good agreement between models and data; 15 pages for the fringe finder, 8 pages for the phase-reference source

Calibrated visibilities against u,v distance for:
ARP299A: pdf , or png .
J1128+5925: pdf , or png .
4C39.25: pdf , or png .
Comments.

u,v coverage for:
ARP299A: pdf , or png .
J1128+5925: pdf , or png .
4C39.25: pdf , or png .
Comments.

Crude maps of sources:
ARP299A: pdf , or FITS .
J1128+5925: pdf , or FITS .
4C39.25: pdf , or FITS .
Comments.