[daip] VLBI questions

[Cheng-Yu Kuo]

    Hi, Amy:

   Thanks for your response and suggestions. When I loaded the data
from the tape, I loaded both passes at the same time. AIPS just
automatically sorted the data from the two passes (geodetic and the
main observations) into different UV files. Each file contains 8 IFs.
Among the 8 IFs, 4 IFs are assigned to FREQID 1 while the other 4 IFs are
assigned to FREQID 2.

   The problem is that there are very very few data with FREQID 2 in
both passes. When loading the data with FITLD, I realized that FITLD
is loading the data with FREQID 1 most of time (see the following
example). So, I still don't understand why the FREQID 2 data is not
seen very often when I load the data from the tape. Both FREQIDs
should have equal amount of data in both passes. Do you have any
ideas? Thank you very much!

regards
chengyu

ps:  The following example is data for the geodetic mode.

chimp.> FITLD1: ---------- FILE   4 LOADED ----------
chimp.> FITLD1: Data with weight <  0.80 will be permanently flagged
chimp.> FITLD1: Sky frequencies (MHz) before re-ordering occurs:
chimp.> FITLD1: Incoming FREQID #   1
chimp.> FITLD1: 21629.84  21629.84  21643.90  21660.08
chimp.> FITLD1: Warning: table type OB is of zero length
chimp.> FITLD1: Attaching data to N6323_0429  .UV    .   2 Vol:   4
chimp.> FITLD1: CL table interval set at  0.10 minutes
chimp.> FITLD1: Current file has    12180 visibilities
chimp.> FITLD1: File ref. freq:    21629.84 MHz
chimp.> FITLD1: Found 1709+431         at   0/03:41:42 src #   3 was    1
chimp.> FITLD1:                                        fqid #   1
chimp.> FITLD1: Found 1705+456         at   0/03:42:11 src #   2
chimp.> FITLD1: Found 1709+431         at   0/03:42:40 src #   3 was    1
chimp.> FITLD1: Found 1705+456         at   0/03:43:10 src #   2
chimp.> FITLD1: Found 1709+431         at   0/03:43:41 src #   3 was    1
chimp.> FITLD1: Found 1705+456         at   0/03:44:11 src #   2
chimp.> FITLD1: Found 1709+431         at   0/03:44:40 src #   3 was    1
chimp.> FITLD1: Found 1705+456         at   0/03:45:12 src #   2
chimp.> FITLD1: Found 1709+431         at   0/03:45:41 src #   3 was    1



User signature file

On Fri, 14 Sep 2007, Amy Mioduszewski wrote:

> Hi Cheng-yu,
>
> 1.  Your data has several complications.  First, you observe in two completely
> different modes: a geodetic type mode with 8 widely spaced IFs and one
> polarization and another mode with 8 IFs and both RCP and LCP, but a very odd
> setup.  Also had to be correlated in two different passes.  I am not sure how
> the AIPS will react to the weird setup of the RCP/LCP part of the data though,
> it looks like you have:  2IFs at 21630.08 RCP and LCP; 1IF at 21644.13 LCP
> only;2IFs at 21660.32 RCP and LCP;1IF at 21675.8 LCP only and; 2IFs at 21693.48
> RCP and LCP.
>
> 2.  You have no SC data because the disk-pack from SC was corrupt and they could
> not recover it the data (that should have been in the PI letter).
>
> Amy
>