EVN User Experiment Pipeline Feedback


Pipeline feedback for experiment EP068A_1. 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 Nov 18 18:14:20 CET 2010 muehle@jive.nl

General Comments. ( Brief data summary and scan listing )
Pass 1: phase center on Arp299A

C-band (6 cm) continuum EVN experiment, observed on 28 May 2010. The data rate was 1024 Mbps (8 x 16 MHz subbands, dual polarization, two-bit sampling). The target source 'Arp299A' was calibrated using the phase-reference source 'J1128-5925'. The calibrator source '4C39.25' was the fringe finder. In this pipeline reduction, Ef, Wb and Mc served as reference antennas and Ef as plot reference, i.e. except for the autocorrelations, the plots show baselines to Ef.
10 EVN stations were scheduled in this experiment: Cm, Ef, Jb, Mc, On, Sh, Tr, Ur, Wb and Ys. The data transmitted by microwave link from Cm are in subbands 2+3 (IF3+4). Ef missed scan #4 due to a long slewing time. Mc reported severe RFI. On reported a tracking problem around 12:52 UT and possibly other problems around 13:10 UT and 15:10 UT. Tr could not record for about an hour after the start of the experiment due to data throttling, so scans #1-21 were lost. Scans #126-129 are missing, too. Ur reported formatter problems, so that part of the data may be bad. A first analysis suggests that scans #24-26, #30-37, #42-48 and #125-129 may be affected. At Ys, two cracks in the main reflector structure were discovered, so that the antenna could not be moved. Wb used 12 antennas in phased-array mode. More details about the observations and the data can be found in the letter to the P.I. which is also available from the archive (section "Standardplots").

The EVN reliability indicator (ERI) for this experiment was ERI = 0.74 . ERI* = 0.74 . (Cm=1, Ef=1, Jb=1, Mc=1, On=1, Sh=1, Tr=0.79, Ur=0.86, Wb=1, Ys=0)

Plots of the autocorrelations
Comments.
bandpasses look fine and generally stable; Ur: at times oscillations in all USB channels (IF2+4+6+8/R+L), mostly during bad scans listed above; 258 pages

plots of the uncalibrated amplitude and phase against time
Comments.
phases of the calibrator sources can be followed even in the uncalibrated data; Cm: transmitted signal is in IF3+4; 32 pages

Plots of the uncalibrated amplitude and phase against frequency channel
Comments.
phases can be followed in the calibrator sources; amplitudes seem to be stable; Cm: transmitted signal is in IF3+4; Ur: some bad scans (see above); 250 pages

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

TSYS against time
Comments.
Ef: unusual fluctuations of T_sys in LCP channels; On: increase of T_sys in all channels at ~15:00-15:30 UT; Mc: increase of T_sys in all channels at ~14:15-15:10 UT; Tr: increase of T_sys in all channels at ~18:00-19:00 UT; Ur: increase of T_sys or missing measurements in all channels at ~14:45-15:20 UT; a few outliers; 15 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.
curves match closely those of T_sys vs. time; a few spikes due to outliers in T_sys; 15 pages

Fringe-fit phase solutions (including Parallactic Angle correction).
Comments.
reference antenna: Ef, drift in phases reflects the parallactic angle correction; Cm: transmitted signal is in (parts of) IF3+4, fast fringe rotation; 14 pages

Fringe-fit delay solutions
Comments.
reference antenna: Ef; delays of the order of (tens of) nanoseconds; Cm: corrections larger in IF4/R+L, a couple of outliers in IF3/R+L, one may want to flag the parts of the IFs without signal; Ur: large outliers during bad scans; 14 pages

Fringe-fit rate solutions
Comments.
reference antenna: Ef; rates of the order of a few mHz; Ur: large outliers during bad scans; 14 pages

Telescope bandpasses
Comments.
reference antenna: Ef; in general, bandpasses look good; phases close to zero except for the edges of the bandpasses of Wb, Sh and a few individual IFs of other stations; Cm: may want to flag the parts of the IFs without signal before fringe fitting; 2 pages

Calibrated amplitude and phase against time (a priori amplitude calibration and fringe-fit solutions applied).
Comments.
phases of calibrator sources close to zero; in general, amplitudes look reasonable; Cm: phases and amplitudes in IF4/L+R bad (see above); 32 pages

Calibrated amplitude and phase against frequency channel
Comments.
phases of calibrator sources close to zero; amplitudes look generally stable; Cm: transmitted signal is in parts of IF3+4 Ur: a few bad scans (see above); 250 pages

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

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

Phase corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
J1128+5925 .
ARP299A (not available) .
4C39.25 .
Comments.
refant: Ef; except for Cm and a couple of outliers, phase corrections in general less than 10 degrees for 4C39.25 and less than 20 degrees for J1128-5925; 14 pages per source

Amplitude corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
J1128+5925: pdf , or text file , or statistical summary .
ARP299A: pdf (not available) , or text file (not available) , or statistical summary (not available) .
4C39.25: pdf , or text file , or statistical summary .
Comments.
Cm: most gains far from 1 (see above); Ur: some bad gains/outliers (see above); 14 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.
T_sys measurements reflected in sensitivities; a few spikes; 14 pages

Residual closure phase (visibility closure phase with model closure phase subtracted) for:
J1128+5925 .
ARP299A (not available) .
4C39.25 .
Comments.
closure phases generally clustered at a value close to zero; scatter a bit larger in loop that include Cm; 17 pages per source

Calibrated visibilities and the source model of:
J1128+5925 .
ARP299A (not available) .
4C39.25 .
Comments.
generally good agreement between data and models; Cm: very noisy (see above); Ur: some bad times (see above); 32 pages per source

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

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

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