RE: [alma-sw-ssr] Offline Requirements v3.1

[mel wright 456 <wright@astron.berkeley.edu>]

Tim,
	I'm not sure what 'Interoperability' means
so let me give an example:

Most image analysis packages have a module which can be executed:
CONVOLVE(image, beam, method, output_image)

Radio astronomers have developed algorithms we could supply:
DECONVOLVE(image, beam, method, output_image)

where method= clean[Hogbom,Clark,SDI,mfsclean,MRclean,maxen,maxempty,etc]

If these algorithms are written in an modular fashion, it should
not require much extra work to write the code so that
it can be incorporated into and invoked from other packages.
I think it is appropriate to state this as a high priority requirement.

The users have probably already imported the
image and beam into their favorite package via FITS.
ALMA could provide them with efficient code to do the appropriate
deconvolution.

	I agree uv-data is a much harder problem. I see
ALMA as an imaging machine, and most users will not deal with uv-data.

		Melvyn 
> 
> Interoperability between packages has been talked about at ADASS for
> a number of years (>5) with no substantial advances for the major
> packages. It's a hard problem, made more so by data formats (it's
> easy to agree cross package on images but not on visibility datasets)
> and technology (e.g. many people argue that CORBA is too heavy weight
> for what we need to do). 
> 
> I'd recommend adding interoperability as a desired but not essential
> feature, but I bet that the costs will rule it out.
> 
> Exporting data to another package is much simpler but is covered
> already by the requirement to write FITS.
> 
> Tim
>  
> > What I am suggesting is that the efficiently coded, radio-astronomy
> > specific algorithms could be provided with clean interfaces for
> > use (perhaps as externally called routines) from other packages
> > which the user might prefer to use. As Mark notes, using aips++
> > these algorithms are  "well-integrated with the data", but the
> > IR astronomer may wish to work in a more familiar environment,
> > better suited to data from some other instrument.
>
> The scientific potential of ALMA will be best realised by
> making it easy for a wide community of users to analyse the
> data in a wide range of packages, rather that by forcing them
> to use a specific custom built environment. A corrolary is
> the algorithms developed by the radio astronomy
> community may have application in other fields if they are
> available in other packages.
>  
> Melvyn
>