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Ken Sowinski wrote:
<blockquote cite="mid:Pine.GSO.4.64.1103171402500.5846@eki" type="cite">
<pre wrap="">Some comments below. Some of this was learned by running the file,
with some corrections, again and watching what happened. This new
version if you want to look at it is rfisurvey_002 from 1902 to 1952 UY.
Ken
On Thu, 17 Mar 2011, Rick Perley wrote:
</pre>
<blockquote type="cite">
<pre wrap=""> ...</pre>
</blockquote>
<blockquote type="cite">
<pre wrap="">2) All lower sideband tunings (all of X-band, and Ka-band from 26
through 32 GHz) have spectra which are both mis-labeled and
mis-ordered. Mis-labeled means that the frequencies in the headers are
incorrect. Mis-ordered means that the eight subbands are incorrectly
placed: subbands 1 and 8 are interchanged, subbands 2 and 7 are
interchanged, etc. The former problem is corrected if we load in an
alternate SDM (from /home/mctest/evla/mcaf/workspace). The latter
problem is not corrected by this -- but Lorant has written a special
BDFin script which correctly re-orders these subbands upon loading into
AIPS. It seems to me that these new issues need to be corrected
automatically without users having to invoke special scripts.
</pre>
</blockquote>
<pre wrap=""><!---->
Prompted by Bryan's earlier email email, I describe what was done.
There was one VCI document for the entire file configuring eight 128 MHz
subband pairs to cover 1 GHz all fed to two quadrants, providing 256 lags
each. The tuning sequence starts with L band and progresses up through
Q band, in 1 GHz steps. When a sideband change occurs, the executor
creates a VCI "modify" document to the correlator. That all seems to
work as expected. The production MCAF does not see this, so creates
incorrect frequncy labels. The test MCAF examines the "observe" document
(where the SSLO is already examined) to learn the sideband sense and
correctly label the subbands in frequency space. When the OPT generated
VCI documents for sideband changes it must have changes the ordering of
sidebands in a way to make the result look like a natural ordering;
MCAF, I suspect, does nothing like that.
</pre>
</blockquote>
<br>
Spectral window ("sw") indices are probably the reason.<br>
<br>
Model-to-script suppresses a VCI msg when the *only* thing that changes
from one msg to the next is sideband sense. For OSRO (or any
observation w/ one subband per baseband) this suppression will happen
under just the right conditions, but it is not generally applicable to
all band changes. In particular if there are multiple subbands in a
baseband, it is ~not~ appropriate to suppress the VCI msg. This is
because sw indices are ordered by sky frequency of the window, not by
its position in the baseband.<br>
<br>
I set up a test on webtest's OPT where i had one scan each for bands C,
X, K, in that order. Each of these was set up using extended OSRO
& had 8 SBs of bw=128MHz per BB. Model-to-script produces 3, not
one, VCI files. For a similar sched block using OSRO (1 sb per bb)
cfgs, then one VCI file is produced (the change into & out of X is
suppressed).<br>
<br>
So, to run this by hand, one may not take the shortcut of using a
single VCI file.<br>
<br>
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