[daip] [!6280]: aips - Dispersive delay fitting in AIPS

[Eric Greisen]

Eric Greisen updated #6280
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       Staff (Owner): Eric Greisen (was: -- Unassigned --)
                 Due: - Cleared - (was: 06 March 2015 02:37 AM)

Dispersive delay fitting in AIPS
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           Ticket ID: 6280
                 URL: https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/6280



I am starting to look at this.  The first step would be to
do something with   MBDLY.  That task is rather odd - it is
given the delay at each IF but insists on fitting the phases
in the SN table, complete with all the ambiguity that 
introduces.  Those phases, at least in modern times, are
simply the SB delay * frequency and so make little sense
to use.  I propose adding in new operation that ignores
the older operation and does a least squares fit of the SB
delays for an MB delay and a dispersion.  Then it will
correct the SB delays for the dispersion (or optionally
replace them with the MB delay) and recompute the phases
as FRING does.

I don't know anything about the guts of DELZN but that might
be an interesting place for this too.

And, of course, CLCAL currently does not do anything with
a dispersion in an SN table.  Presumably, it should add it to
any dispersion already in the CL table.

Cheers

Eric




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