[Difx-users] DiFX Support for RDEF {External}

[harro verkouter]

Hi all,

Yes Stuart has been in contact about supporting it in jive5ab. The raw
samples seem to be simple enough to decode in themselves, but what I
suspect is, that due to its non-framed format, decoding it might be more
tricky than anticipated (I know several bits of code in jive5ab are firmly
built on the assumption that the data is a stream of relatively
small/finite size frames, each with a header and a payload and that,
possibly, really big frames, might break those assumptions).

Looking at the spec (https://public.ccsds.org/Pubs/506x1b1.pdf) - or what I
believe to be the "RDEF" spec - the question is: what do you _actually_
mean by supporting RDEF? The code being able to read an observation file
and process all the product files in one fell swoop? (For the jive5ab case:
how would like like RDEF support to /look/ like? For a correlator running
off a config file with file names in it that the multitude of RDEF product
files seem a natural match, but for jive5ab much less so.)

Personally, I think it might be worthwhile checking if support for RDEF
could be built into the "baseband" package (
https://baseband.readthedocs.io/en/stable/index.html). It's Python and
associated w/ astropy (lots of useful basic tools already available) and
for translating/filtering VLBI data it might be a more natural place.

Cheers,
M


On Tue, 8 Oct 2024 at 02:10, Stuart Weston via Difx-users <
difx-users at listmgr.nrao.edu> wrote:

> Thanks Adam,
>
> I have been corresponding with Marjolein Verkouter on jive5ab -> rdef.
>
> Stuart
>
> On Tue, Oct 8, 2024 at 12:56 PM Adam Deller <adeller at astro.swin.edu.au>
> wrote:
>
>> Hi Stuart.
>>
>> No-one has implemented native support for RDEF as far as I know. I had an
>> email exchange from Christopher Volk from JPL (
>> christopher.p.volk at jpl.nasa.gov) about RDEF a couple of years ago. At
>> the time I advised him to use a converter, but you could follow up to see
>> if he investigated native support. I think it would certainly be possible,
>> but not a quick 30 minute job to add it to mark5access. (Also not sure
>> whether jive5ab supports it, which might enable you to at least do it on
>> the fly at correlate time).
>>
>> Cheers,.
>> Adam
>>
>> On Tue, 8 Oct 2024 at 08:46, Stuart Weston via Difx-users <
>> difx-users at listmgr.nrao.edu> wrote:
>>
>>> Spent a bit of time searching through the wiki and documentation looking
>>> for Raw Data Exchange format (RDEF) support. We are looking to correlate
>>> VDIF-RDEF data. We have a python program that will convert VDIF to RDEF,
>>> but would be nice if we could take RDEF native into DiFX for correlating
>>> with our VDIF.
>>>
>>> Just wondering if that has been thought about or is hidden somewhere?
>>>
>>> We are looking at some Goldstone Delta-DOR RDEF data and correlating
>>> with our 30m data for a future cooperation.
>>>
>>> Stuart Weston
>>> Space Operations NZ Ltd
>>>
>>>
>>> _______________________________________________
>>> Difx-users mailing list
>>> Difx-users at listmgr.nrao.edu
>>> https://listmgr.nrao.edu/mailman/listinfo/difx-users
>>>
>>
>>
>> --
>> !=============================================================!
>> Prof. Adam Deller
>> Centre for Astrophysics & Supercomputing
>> Swinburne University of Technology
>> John St, Hawthorn VIC 3122 Australia
>> phone: +61 3 9214 5307
>> fax: +61 3 9214 8797
>> !=============================================================!
>>
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