[asac] ASAC topic

[Stephane Guilloteau]

Dear Tetsuo,

    I  think we should definitely discuss the Enhanced Correlator case
further.
However, the costing has you presented it is incomplete because it does not
take into account the induced costs on the Data Processing & Archiving.
Since the
enhanced correlator may produce 16 times more channel on average than the
baseline correlator, real-time processing will be significantly more heavy,
and thus
more costly. This should be estimated and included in the "Enhanced
Correlator"
additional cost.

    Concerning the Archiving, the task is more complex, since it depends on
the
archiving requirements. There is first a scientific issue on how many
channels should
be archived, and then a costing excercise to be done later.

    Altogether, these extra costs may amount to 5 to 10 M$, perhaps even
more, i.e. may cost us one or more frequency band...

    I believe it perfectly OK for the ASAC to indicate priorities even if
the exact costing is
not known in advance, but the ASAC should nevertheless be aware of the
possible cost consequences of the priorities.

        Stephane



-----Original Message-----
From: Tetsuo Hasegawa <tetsuo.hasegawa at nao.ac.jp>
To: asac at NRAO.EDU <asac at NRAO.EDU>
Cc: lmsa-pro at nro.nao.ac.jp <lmsa-pro at nro.nao.ac.jp>; lmsa-shoi at nro.nao.ac.jp
<lmsa-shoi at nro.nao.ac.jp>
Date: Tuesday, March 13, 2001 9:58 AM
Subject: [asac] ASAC topic


>Dear Ewine and Geoff,
>
>As Yasuo Fukui is now travelling, I propose a topic for the coming ASAC
>telecon tomorrow.
>
>Before the Florence meeting, ASAC has been asked by ALG on the priority
>among the enhancements enabled by Japanese participation under a 10% cut
>(see the attached pdf document).  At the beginning of the Florence meeting,
>we are told that ACC now wants ASAC to think about the priorities under 20%
>cut.  We tried to do so in the course of the meeting, with a very miserable
>mood, and managed to squeeze out some choice.  We did not have time and
>energy in Florence to think of the 10% case.  At the same time, ASAC have
>sent a letter to ACC to think the 20% cut over again.
>
>The above sequence of events means that we still need to make a
>prioritization for the 10% cut constraint.  I would like to present a model
>supported by Japanese ASAC members as follows.  We believe that it greatly
>enhances the scientific capability of ALMA in many ways while staying
within
>the budgetary constraints set by the 10% cut.  We want to hear the ASAC
>thoughts on Wednesday.
>
>Net new resource assumed $140M (under 10% cut, overhead of ALG-estimated
>$50M removed; see the pdf document)
>
><Three major enhancements>
>1) Add 2 receiver bands (Bands 8 and 10): $30M
>2) Build ACA with 6 bands: $70M
>3) Build the enhanced correlator: $35M
>--------------------
>Total: $135M
>
><Rooms for furhter adjustments/tradeoffs>
>*adding 1 or 2 receiver bands (Bands 4 and 1): +$10 to 20M
>*give up 2SB capability: -$20M (estimate of cost reduction being made at
>Nobeyama)
>*refinements of the estimate of "overheads"
>