EVN User Experiment Pipeline Feedback


Pipeline feedback for experiment GB060B. If you have any comments on this experiment please email the address below.
A detailed description of the pipeline output is available.

Last updated: Mon Mar 23 18:18:57 CET 2009 muehle@jive.nl

General Comments. ( Brief data summary and scan listing )
7mm global VLBI experiment, observed on 16 October 2008. The data rate was 512 Mbps (8 X 16 MHz subbands, dual polarization, two-bit sampling). The target source was 'CYG-A'. The sources '1749+096', '2013+370', and 'BLLAC' were also observed as calibrators. At the start of the observations, the pointing of Gb was checked using '3C345'. '1749+096' and 'BLLAC' serve as polarization calibrators. In the pipeline processing, the solint was 4 min. and Gb was used as the reference antenna. The plots show baselines to either Ef or Gb.
10 VLBA stations, 3 EVN stations, the GBT and one EVLA antenna participated. Sc was hit by a hurricane the day before the observations and was still recovering, which is probably the reason why there were no fringes to Sc for this experiment. At the VLA, the EVLA antenna #16 participated, being located on pad W6. At On, the outside temperature dropped rapidly during the last few hours of the experiment, leading to frost on the radom and in turn to increased system temperatures, but the observations continued as scheduled. A detailed description of the individual antenna performances can be found in the PI letter, available in the section "Standardplots". Please note that the scan numbers given below refer to the numbering in the observed schedule (see for example Standardplots/gb060b.sum), not to the scan listing given on this page.

The EVN reliability indicator (ERI) for this experiment was ERI = 1.0 . ERI* = 1.0 . (EF=1.0, ON=1.0, NT=1.0, double-check Tsys of On!)

Plots of the autocorrelations
Comments.
no RFI detected; in general, stable bandpasses; 201 pages

plots of the uncalibrated amplitude and phase against time
Comments.
as expected, very fast phases; 56 pages

Plots of the uncalibrated amplitude and phase against frequency channel
Comments.
even uncalibrated, phases of calibrators look good on short baselines (intracontinent), except for Fd/IF1/R and Nt/IF4/R at some times; some temporary glitches of individual stations; 272 pages

The uncalibrated amplitude and phase of the crosshand correlations against frequency channel
Comments.
even uncalibrated, phases of calibrators look good on EVN baselines, sometimes also on VLBA baselines; 150 pages

TSYS against time
Comments.
Ov: high T_sys at 17:50-19:00 UT = source below horizon; Hn: rain at ~17-19:30 UT, 22-24 UT?; Yy: high T_sys before 18 UT = not on source; Sc: see General Comments; On: spike in T_sys at ~1 UT, fast drop in temperature/frost?; 12 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.
generally, good match to T_sys vs. time (see above); 12 pages

Fringe-fit phase solutions (including Parallactic Angle correction).
Comments.
refant = Gb, drift in phases reflects the parallactic angle correction; as expected, very fast phases; 12 pages

Fringe-fit delay solutions
Comments.
refant = Gb; except for some outliers, delays of the order of tens of nanoseconds; Hn: IF3/R many outliers, IF4/R jump in delay; 12 pages

Fringe-fit rate solutions
Comments.
refant = Gb; rates of the order of (a few tens of) mHz; Nt/IF4/R: few solutions before 22 UT; Fd: constant rates at 7-8 UT (no Gb); 12 pages

Telescope bandpasses
Comments.
refant = Gb; amplitudes and phases well aligned (averaged over the bandpass); 4 pages

Calibrated amplitude and phase against time (a priori amplitude calibration and fringe-fit solutions applied).
Comments.
phases improved with the pipeline calibration process, but not surprisingly, they are still much noisier than those at lower frequencies; careful flagging and calibration of the data necessary; 56 pages

Calibrated amplitude and phase against frequency channel
Comments.
phases best constrained in the strongest sources and on short baselines; some temporary glitches in individual IFs/pols at individual stations; 267 pages

Naturally weighted dirty map (not useful for bright sources) produced before self-cal of:
CYG-A: pdf (not available) , or FITS (not available) .
3C345: pdf (not available) , or FITS (not available) .
BLLAC: pdf (not available) , or FITS (not available) .
1749+096: pdf (not available) , or FITS (not available) .
2013+370: pdf (not available) , or FITS (not available) .
Comments.

Uniformly weighted dirty map (not useful for bright sources) produced before self-cal of:
CYG-A: pdf (not available) , or FITS (not available) .
3C345: pdf (not available) , or FITS (not available) .
BLLAC: pdf (not available) , or FITS (not available) .
1749+096: pdf (not available) , or FITS (not available) .
2013+370: pdf (not available) , or FITS (not available) .
Comments.

Phase corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
CYG-A .
3C345 .
BLLAC .
1749+096 .
2013+370 .
Comments.
12 pages per source

Amplitude corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
CYG-A: pdf , or text file , or statistical summary .
3C345: pdf , or text file , or statistical summary .
BLLAC: pdf , or text file , or statistical summary .
1749+096: pdf , or text file , or statistical summary .
2013+370: pdf , or text file , or statistical summary .
Comments.
pipeline calibration ok; data should be carefully inspected, flagged and calibrated; 11-12 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.
12 pages

Residual closure phase (visibility closure phase with model closure phase subtracted) for:
CYG-A .
3C345 .
BLLAC .
1749+096 .
2013+370 .
Comments.
54-66 pages per source

Calibrated visibilities and the source model of:
CYG-A .
3C345 .
BLLAC .
1749+096 .
2013+370 .
Comments.
except for residual short-time phase fluctuations, generally good agreement between data and model; 47-56 pages per source

Calibrated visibilities against u,v distance for:
CYG-A: pdf , or png .
3C345: pdf , or png .
BLLAC: pdf , or png .
1749+096: pdf , or png .
2013+370: pdf , or png .
Comments.

u,v coverage for:
CYG-A: pdf , or png .
3C345: pdf , or png .
BLLAC: pdf , or png .
1749+096: pdf , or png .
2013+370: pdf , or png .
Comments.

Crude maps of sources:
CYG-A: pdf , or FITS .
3C345: pdf , or FITS .
BLLAC: pdf , or FITS .
1749+096: pdf , or FITS .
2013+370: pdf , or FITS .
Comments.
all sources detected