AIPS HELP file for WHATSNEW in 31DEC24

As of Wed Oct 9 3:46:05 2024

HELP SECTION

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                 WHATSNEW in 31DEC99 (sic) AIPS
                       AIPS for the Ages

                   last edited 19 March 2019

31DEC99 was a new form of AIPS (non)-release.  It was supposed to
remain always under development and user sites were expected to
install it and then stay current via a "midnight job" update
procedure.  But the sites have been resistant and we are now faced
with "which date 31DEC99 do you have".  So we are going back to, now
annual, releases, beginning with 31DEC00.

Sites wishing to have code less than 1 year old will still need to
fetch the current TST code - now 31DEC19 - and then run the MNJ
($HOME/do_daily.) update procedure to stay current.

AIPSLetters are issued every 6 months.  Get to these via the WWW:
        http://www.aips.nrao.edu/
or find the files in $AIPSPUBL/LET*.PS.  For changes over the last
several years, see the AIPSLetters which contain more expansive (and
hence clearer) descriptions of the changes in AIPS over the many
releases sines 31DEC99.

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Changes in 31DEC19 compared to 31DEC18 (before patches)
1. BPASS has new normalization options to use medians rather than
   means.
2. Modeling code had trouble when computing the model without data,
   particularly when doing multiple models over frequency.  MODL
   now fixed for OOSUB as well as UVSUB.
3. TYSMO was corrected to really enforce the clipping parameters, to
   flag only those parameters requested, to apply the FG table to the
   SY data correctly, and to allow scaling in each scan for the MWF
   clipping.
4. The sign of the parallactic angle correction was corrected when
   translating linear polarizations into Stokes.
5. AIPS was corrected generally to use the PO table for moving sources
   (planets) when computing elevation, hour angle, and azimuth and
   when recomputing UVW for shadowing and in UVFIX.
6. The CookBook was updated for SNBLP, TVIEW, FITLD VLB weights, and
   the above.

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