P.I. letter

To: Bayandina
Subject: N20C1 FITS files ready on the EVN Archive

Dear PI,

  We have examined your project (N20C1,25/02/2020) and the
data are ready for distribution to you.  You can download the data
directly from the EVN Data Archive (see below).  Contact your support
scientist to arrange a password for your experiment. 


The experiment scheduled the following telescopes: JbWbEfO8T6UrTrYsHhSvZcBdIrCmDaDeKnPi. 

Your experiment was processed with the following parameters:
Pass1: 18 Tels, 8 band X 4 pols, each with 64 points, 2 sec int.

The originally recorded disks from the stations can be released after
two weeks.  If you have any questions, contact us at jops@jive.eu.

  EVN and Global VLBI Observations correlated at at JIVE are now
automatically calibrated via a pipeline process. You will receive email
notification when the pipeline is complete. In particular, the a priori
amplitude calibration table (and the associated, final ANTAB file -- note
that it is better to use this file from the pipeline rather than the
individual-station antabfs files available from the "Station Logfiles"
tab of the archive), plus various other tables and plots will be available 
to download from the EVN archive (subject to the EVN Data Archive policy as 
discussed below).  A description of the pipelining process can be found at:

    www.evlbi.org/pipeline/user_expts.html


  The EVN data archive at JIVE is now a central location for obtaining
the information you need in reviewing your project.  You can find
network feedback from the stations, standard plots from the correlation
review done here prior to distribution, pipeline results, and the FITS
files themselves. Contact your support scientist to arrange for a
password with which you can download your FITS file(s) from the archive
directly.  See the EVN Users' Guide in www.evlbi.org for a link to the
EVN Archive policy -- in short, data from sources you identified as
target/private in pre-correlation e-mail will not be made public, nor
will pipeline images be available from them, for one year from
distribution.  The archive can be accessed via:

    www.jive.eu/select-experiment

(or via the menu items of the main jive page www.jive.eu).  Once in
this portal to the EVN data archive, you can click on your experiment
in the pull-down menu in the "Select Experiment" window; then click on
the link "Show Experiment" that will appear immediately below this.
You will then see a new window for your experiment, from which you can
select from the various sorts of data available from the menu row along
the top: 
  *) Station Feedback = information provided by the stations' VLBI friends
        about the conduct of the experiment
  *) Station Logfiles = sched-based files  you uploaded to VLBEER, observing
        log-files from the stations, other unprocessed station-generated files.
  *) Standard plots = the plots described below in a variety of formats,
        a copy of this cover letter
  *) Pipeline = pipeline plots; the ANTAB & UVFLG files used in pipelining
  *) Fitsfiles = FITS files, plus an associated README in case there are
        multiple correlator passes each with its own set of FITS files.

The proprietary period for data on the EVN archive is 1 year (6 months
for target-of-opportunity observations) -- the raw FITS files and pipeline
results relating to sources you identified as "private" receive password 
protection during the proprietary period.  For more details, see
    www.evlbi.org/user_guide/archive_policy.html  


  Papers that result from your EVN observations should carry the
standard EVN acknowledgment:

    The European VLBI Network is a joint facility of independent European,
    African, Asian, and North American radio astronomy institutes.
    Scientific results from data presented in this publication are 
    derived from the following EVN project code(s):  N20C1

If your observations included e-VLBI segments or were eligible for 
RadioNet support, please visit  
    www.evlbi.org/index.php/acknowledgements
for the further acknowledgments to include in your papers.


------------- o ---------------

General Remarks:

  In the process of checking your experiment we have created plots of 
the weights vs time, auto- and cross-correlation spectra for a few
one-minute intervals, and the behavior of amplitude and phase in time.
These plots and an explanatory description can be found in your
experiment's standard plots section of the EVN data archive.

  As part of the check-out procedure, we evaluate the quality of all 
data with low weights and set an appropriate cutoff for flagging.  
In this experiment the cutoff was set at 0.9.  
This cutoff flagged 0.48% of the data.

  If you observed with 2-bit sampling, your data have been corrected 
with a van Vleck correction to account for the statistics of high/low
bits for each BBC's data stream at each station.  Thus you shouldn't 
run ACCOR in AIPS.  It should be okay to use autocorrelations for 
bandpass corrections or to use ACFIT.  For AIPS versions starting
with 31DEC13, you should set DIGICOR to -1 in FITLD (previously, it
would do that automatically if the array was not VLBA).


Remarks on plots or individual stations:

   Jb:

   Wb:

   Ef:

   O8:

   T6: Didn't participate due to a problem with the fiber optic transmission.

   Ur: Could not participate due to coronavirus restrictions.

   Tr: Due to problems with the telescope's calibration system there are no valid T_sys data for the experiment.

   Ys:

   Hh:

   Sv:

   Zc:

   Bd:

   Ir:

   Cm: Could not participate due to a fibre break on the antennas' site.

   Da: For e-MERLIN stations ANTAB files with nominal values are used.

   De: Could not participate due to a fibre break on the antennas' site.

   Kn: Could not participate due to a fibre break on the antennas' site.

   Pi: The station is out for the entire EVN session; stopped for a cooled C band PAF testing.



Further remarks: