[asac]Re: Draft of ASAC Report: section on RSC

[K. Tatematsu]

Dear Stephane and John,

thank you for your reply.

At 14:51 02/04/03 +0100, John Richer wrote:
>One paradigm of the VO and the Grid is data-location independence.

Yes, I admit that my argument does not match the location-independent paradigm.

>Geographically distributed archives are 'federated' through special
>software, allowing access from anywhere on the planet.  This works
>because for most applications, one does not need to complete
>petabyte-scale 'cross correlations': one is interested for example in
>selecting all sources in the northern sky with SLOAN magnitudes below
>20 which have ALMA 350 GHz fluxes greater than 5 mJy.  The actual data
>volume transmitted over the global networks needed to do this is much
>smaller than the raw-data archive sizes.

Yes, it is true if we can put almost all essential information into a 
compact-enough
catalog.  It is not difficult to make a point source catalog from two 
dimensional images
at a few or several optical-IR bands.  However, the millimeter and submillimeter
data often contain irregular shaped diffuse emission also having irregular 
velocity
structure in three dimensions.
My concern is how we can build such catalogue(s) efficiently.
If it is OK, it would not be necessary to consult the raw data for cross 
correlation
and the network speed requirement depends on compression efficiency of the 
calatogue.

Now, I feel that I should stop here.
Sorry for confusion.

With best regards,
Ken