RE: [pafska] PAFSKA CoDR documentation
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From: <devos_at_email.protected>
Date: Wed, 08 Jun 2011 09:39:53 +0200
Dear Carole,
I'm not sure the current document set shows the kind of system-level
approach you're sketching. I'm also not sure how well grounded several
of the assumptions are, especially for Total Cost of Ownership. To be
completely frank, I think some of the "typical" figures given are highly
optimistic. I understand the drive to show a PAF system is "better", but
please be careful not to oversell, this might do more damage than good.
In this respect: the reason for including the documents from APERTIF
and others is not "particularly to reflect your technical progress". Of
course this is appreciated, but the primary reason for including this
material is to present various design reference points that provide a
foundation and starting point for technology roadmaps.
Groeten,
Marco.
Dr. Marco de Vos - ASTRON Managing Director
ASTRON, the Netherlands Institute for Radio Astronomy
PO Box 2, 7991 PD Dwingeloo, The Netherlands
eMail: devos_at_astron.nl / www.astron.nl
tel: +31 521 595100 / fax: +31 521 595101
>>> <Carole.Jackson_at_csiro.au> 2011-06-08 00:54 >>>
Dear Wim
Thank you for your comments. The approach for the PAF sub-system, as
discussed at the Utah workshop, is to
1. As far as we can, we include an outline of a PAF system which
addresses the science requirements as (i) defined at the SKA system
level (DRM etc), but (ii) balancing this with a description of what the
PAF system 'could do' in terms that it may well do _better_ than the
baseline design (OBSPFs) if designed appropriately.
2. That for the CoDR we concentrate on a PAF system with a spec as
discussed during the recent PAFSKA telecons; i.e. one around 600 - 1500
MHz or so. This is a system concept that draws strongly on a wealth of
experience (ASTRON, BYU, DRAO, CSIRO) and it this experience we wish to
ensure we include.
3. Following on from points 1 and 2 (above), at Utah our discussion
moved towards proposing PAFs which actually address the whole SKA_1
frequency range (and perhaps SKA_2 too, in time).
The system concept documents reflect these discussions and define sytem
architectures at the Concept level which could be developed to address
either or both of the 'L band' PAF as well as the SKA1 frequency bands
(as defined in memo 130).
At this stage of the CoDR preparation we are working hard to collate
any (and all) information submitted by the PAFSKA partners in time for
Neil's 15 June deadline. We would welcome anyone wishing to assist,
particularly with the top-level documentation, but I trust you
appreciate that time is short.
We recognise that there is a lot of material from ASTRON (and BYU,
DRAO) that needs to be included in the CoDR material, particularly to
reflect your technical progress; we look forward to receiving this from
you this week.
Best regards
Carole
-----Original Message-----
From: owner-pafska_at_atnf.csiro.au [mailto:owner-pafska_at_atnf.csiro.au] On
Behalf Of Wim van Cappellen
Sent: Tuesday, 7 June 2011 9:25 PM
To: pafska_at_atnf.csiro.au
Subject: [pafska] PAFSKA CoDR documentation
Dear colleagues,
With regard to the CoDR documentation:
As I stressed in the April 27 and May 4 telecons, at the CoDR we have
to assess the impact of one or more PAF scenarios on the SKA1 system.
These scenarios can be realistic, pessimistic or optimistic, but they
should defined. We seemed to agree on this in the telecons. However,
the
current version of the CoDR documentation only contains subsystem
descriptions. It would be unacceptable if the documentation would not
contain at least a set of science requirements, a system architectural
design and a cost estimation for one or more scenarios. The impact on
the overall system should be considered since PAFs will also impact
the
digital beamforming, data transport, correlation and postprocessing.
Furthermore, the current version of the documentation contains
"technical progress" of the various subsystems, but the system level
"technical progress" is not included. There have been several
measurement campaigns of PAFs on telescopes, at least at BYU, DRAO and
ASTRON, and I consider their results are highly relevant for the
overall
PAF technical progress. Laurens already submitted a recent APERTIF
paper
which includes our experimental results and I will submit the APERTIF
PDR documentation.
Best regards,
Wim.
Date: Wed, 08 Jun 2011 09:39:53 +0200
Dear Carole,
I'm not sure the current document set shows the kind of system-level
approach you're sketching. I'm also not sure how well grounded several
of the assumptions are, especially for Total Cost of Ownership. To be
completely frank, I think some of the "typical" figures given are highly
optimistic. I understand the drive to show a PAF system is "better", but
please be careful not to oversell, this might do more damage than good.
In this respect: the reason for including the documents from APERTIF
and others is not "particularly to reflect your technical progress". Of
course this is appreciated, but the primary reason for including this
material is to present various design reference points that provide a
foundation and starting point for technology roadmaps.
Groeten,
Marco.
Dr. Marco de Vos - ASTRON Managing Director
ASTRON, the Netherlands Institute for Radio Astronomy
PO Box 2, 7991 PD Dwingeloo, The Netherlands
eMail: devos_at_astron.nl / www.astron.nl
tel: +31 521 595100 / fax: +31 521 595101
>>> <Carole.Jackson_at_csiro.au> 2011-06-08 00:54 >>>
Dear Wim
Thank you for your comments. The approach for the PAF sub-system, as
discussed at the Utah workshop, is to
1. As far as we can, we include an outline of a PAF system which
addresses the science requirements as (i) defined at the SKA system
level (DRM etc), but (ii) balancing this with a description of what the
PAF system 'could do' in terms that it may well do _better_ than the
baseline design (OBSPFs) if designed appropriately.
2. That for the CoDR we concentrate on a PAF system with a spec as
discussed during the recent PAFSKA telecons; i.e. one around 600 - 1500
MHz or so. This is a system concept that draws strongly on a wealth of
experience (ASTRON, BYU, DRAO, CSIRO) and it this experience we wish to
ensure we include.
3. Following on from points 1 and 2 (above), at Utah our discussion
moved towards proposing PAFs which actually address the whole SKA_1
frequency range (and perhaps SKA_2 too, in time).
The system concept documents reflect these discussions and define sytem
architectures at the Concept level which could be developed to address
either or both of the 'L band' PAF as well as the SKA1 frequency bands
(as defined in memo 130).
At this stage of the CoDR preparation we are working hard to collate
any (and all) information submitted by the PAFSKA partners in time for
Neil's 15 June deadline. We would welcome anyone wishing to assist,
particularly with the top-level documentation, but I trust you
appreciate that time is short.
We recognise that there is a lot of material from ASTRON (and BYU,
DRAO) that needs to be included in the CoDR material, particularly to
reflect your technical progress; we look forward to receiving this from
you this week.
Best regards
Carole
-----Original Message-----
From: owner-pafska_at_atnf.csiro.au [mailto:owner-pafska_at_atnf.csiro.au] On
Behalf Of Wim van Cappellen
Sent: Tuesday, 7 June 2011 9:25 PM
To: pafska_at_atnf.csiro.au
Subject: [pafska] PAFSKA CoDR documentation
Dear colleagues,
With regard to the CoDR documentation:
As I stressed in the April 27 and May 4 telecons, at the CoDR we have
to assess the impact of one or more PAF scenarios on the SKA1 system.
These scenarios can be realistic, pessimistic or optimistic, but they
should defined. We seemed to agree on this in the telecons. However,
the
current version of the CoDR documentation only contains subsystem
descriptions. It would be unacceptable if the documentation would not
contain at least a set of science requirements, a system architectural
design and a cost estimation for one or more scenarios. The impact on
the overall system should be considered since PAFs will also impact
the
digital beamforming, data transport, correlation and postprocessing.
Furthermore, the current version of the documentation contains
"technical progress" of the various subsystems, but the system level
"technical progress" is not included. There have been several
measurement campaigns of PAFs on telescopes, at least at BYU, DRAO and
ASTRON, and I consider their results are highly relevant for the
overall
PAF technical progress. Laurens already submitted a recent APERTIF
paper
which includes our experimental results and I will submit the APERTIF
PDR documentation.
Best regards,
Wim.
-- ---------------------------------------------------------------------------------- Wim van Cappellen Head of Antenna Group, APERTIF Project Manager ASTRON - R&D P.O.Box 2, 7990 AA Dwingeloo, The Netherlands Phone: +31 (0)521 595 253, fax +31 (0)521 595 101 E-mail: cappellen_at_astron.nl internet: www.astron.nl ----------------------------------------------------------------------------------Received on 2011-06-08 17:40:44