Re: ALMA Science Software Requirements - an alternate spin

[Robert Lucas <lucas@iram.fr>]

Barry Clark wrote:
> 
> 
> It is not at all clear to me whether information needs to be passed from
> the observing tool to AIPS++ (or whatever).  And it is especially unclear
> to me that the real-time system needs to know about it if it does.  I don't
> think so.

- Well, my feeling is that the observing tool should both write an
observation script, and a on-line data reduction script. Both should
mostly use standard reduction macros, I guess. 


> In my own stuff, I'm guessing that it takes about twice as many man-hours
> to do something on the real-time system as to do the equivalent in the
> non-real-time world.  This is a powerful impetus to keep the real-time
> world as simple as possible.  An ascii script is about as complex as I'd
> like to go.  Looping is probably worth having.  (I did the VLBA control
> system without macros and with looping - both mistakes.)

- the observing scripts need to be tested on a simulator, which has to
be kept up to date with the actual real-time software. 

- we have both loops and macros at Plateau de Bure, and use them a lot.
Most observing programs, however, use a set of standard macros and the
observer input 
is just a set of parameter values and receiver/correlator setup
commands. 

> The design of the scripting language is strongly affected by the question
> of whether we want to allow observers to divide their antennas into
> subarrays and to swap antennas freely between them.  It adds complexity,
> but I can see it might be desirable.

- if two part of the arrays do completely different things (two
different observing programs) then it makes sense to operate them
independently, with 
two independent  scripts, which may be even run on different computers;
If they are used by a same project, should be synchronised,  and produce
output
which should be  combined for data reduction, then they should be
commanded by the same script.  

Regards

Robert

-- 
Robert LUCAS,            Institut de Radioastronomie Millimetrique
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