EVN User Experiment Pipeline Feedback


Pipeline feedback for experiment EP046A. If you have any comments on this experiment please email the address below.
A detailed description of the pipeline output is available.

Last updated: Wed Oct 20 16:47:03 CEST 2004 zparagi@jive.nl

General Comments. ( Brief data summary and scan listing )
UHF spectral line experiment recorded at 64 Mbps (2*4MHz IFs, two polarizations, two bit sampling). The array consisted of Onsala, Westerbork, Effelsberg, Noto, Torun and Urumqi. The observing frequency was ~850 MHz. Recorded on disks, except in Urumqi.

Urumqi produced no fringes in the UHF session. Torun recorded two linear polarizations, Noto a single linear polarization. The others recorded circular polarization. Severe RFI was reported from the stations On, Ef and Nt.

The fringe finders were 3C454.3 and 3C84. J0112+3522 was a phase calibrator nearby the target. Due to a technical problem the first scan of the experiment (3C454.3) could not be correlated. The pipeline had to be modified to allow lower SNR (>5) solutions in FRING since J0112+3522 seemed to be too faint. Note that the stations are less sensitive in this band. Many failed solution were due to the low SNR of the signal, and so the ERI below could not be well estimated.

The estimated ERI (ratio of the number of good visibilities to the expected number of visibilities) is 0.61. The known losses were all due to technical failures. (The Noto RFI may make the situation even worse.) The individual stations contribute to these losses as the following (1 meaning perfect data all the time): Ef - 0.98, Ur - 0.00, Wb - 0.98, On - 0.98, Tr - 0.98, Nt - 0.49/0.50 (a single receiver)

Plots of the autocorrelations .
Comments.
All stations show RFI. It is the most serious in Noto.

Plots of the uncalibrated amplitude and phase against time .
Comments.
Nt: the fringe finders are definitely detected
Ur: some data are missing due to tape problems - no fringes anyway

Plots of the uncalibrated amplitude and phase against frequency channel .
Comments.
Nt: RFI is sneaking through cross-hands data
Wb: IF1 has strong band-edge cutoffs (see station feedback on the tied array)

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

TSYS against time .
Comments.
The Tsys measurements may be corrupted due to the RFI situation in this band.

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.
Tr seems to be more sensitive than expected (SEFD=2000 Jy, see the EVN Status Table). There was a new receiver installed before the EVN session.
Nt: also had a new receiver with previously unknown gain

Fringe-fit phase solutions (including Parallactic Angle correction).
Comments.

Fringe-fit delay solutions .
Comments.

Fringe-fit rate solutions .
Comments.

Telescope bandpasses .
Comments.

Calibrated amplitude and phase against time (a priori amplitude calibration and fringe-fit solutions applied).
Comments.
Wb, Ef and On data look good. There were some detections to Nt and Tr as well. The reference source was too faint.

Calibrated amplitude and phase against frequency channel .
Comments.

Naturally weighted dirty map produced before self-cal of:
J0112+3522: postscript , or FITS .
3C84: postscript , or FITS .
Comments.

Uniformly weighted dirty map produced before self-cal of:
J0112+3522: postscript , or FITS .
3C84: postscript , or FITS .
Comments.

Phase corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
J0112+3522.
3C84.
Comments.

Amplitude corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
J0112+3522: postscript , or text file .
3C84: postscript , or text file .
Comments.

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.
Nt is much less sensitive compared to the a-priori gains. This is probably due to the strong RFI.

Residual closure phase (visibility closure phase with model closure phase subtracted) for:
J0112+3522 .
3C84 .
Comments.

Calibrated visibilities and the source model of:
J0112+3522 .
3C84 .
Comments.

Calibrated visibilities against u,v distance for:
J0112+3522. postscript , or png (smaller)
3C84. postscript , or png (smaller)
Comments.

u,v coverage for:
J0112+3522. postscript , or png (smaller)
3C84. postscript , or png (smaller)
Comments.

J0112+3522: postscript , or FITS .
3C84: postscript , or FITS .
Comments.