Kyoto Meeting

[Hans-Martin Adorf]

Hi Masatoshi,

two corrections:

    * My name is Hans-Martin Adorf (not Adolf).
    * I did not implement ADQL, but a statistical cross-matcher that has
      similar functionality. I hope that it will serve as a
      matcher-engine inside of a SkyNode implementation, once we have an
      ADQL-parser up and running. My matcher uses primary match tables
      returned from a deterministic match-list service, as provided by
      the Vizier-archive at CDS (and by the other Vizier-archive mirror
      servers), and by the SDSS-DR3-archive at  JHU. For each match
      combination (candidate) the matcher computes an optimum position
      along with an estimated statistical uncertanty, and for each
      counterpart in the combination the distance and the Mahalanobis
      distance to the optimum position. The Mahalanobis distances are
      combinaed into a reduced chi-squared which is subsequently used to
      discriminate against unreasonable match combinations. Currently,
      an individual counterpart is not eliminated, if it doesn't fit
      into a cluster of counterparts (by showing too large a Mahalanobis
      distance to the optimum position). In the future I plan to use an
      iterative procedure in order to eliminate individual counterparts,
      which stops when a reasonable match combination is established, or
      when too few counterparts are left. My matcher algorithm is
      similar, at least in spirit, to the algorithm used by the JHU
      folks for SkyServer.

In case you are going to discuss systematic uncertainties(or bias) 
between coordinate systems in the context of matching, I would 
appreciate to receive a summary of the discussion and/or the conclusions 
reached. I am becoming increasingly worried, when the statistical 
uncertainties are getting as small as 100 milliarcsec, as in case of 
SDSS-DR3. I cannot imagine that the coordinate systems in use by the 
different astronomical sub-communities (optical, infrared, radio, ...) 
have systematic errors less than 1 arcsec at an arbitrary point on the 
sky, but I may be wrong. Are there any astrometrists participating at 
Kyoto who could speak with authority?

I wish you success with your meeting at Kyoto. Sorry, to not being able 
to join you guys, due to a shortage of travel funds and other reasons.

Cheers
Hans-Martin


Masatoshi OHISHI wrote:

> Hi VOQL members,
> (c/c DAL members)
>
> In February I posted the following message to the group, and I observed
> no suggestions. Doug Tody agreed to have a joint session with the DAL
> group.
>
> >1) implementation status of ADQL-0.9 / SkyNode
> >2) development on the "Virtual Column" concept to be incorporated into
> >  ADQL-1.x (?); this item may be discussed jointly with the DAL group
> >3) other related proposals / reports
>
> Therefore I would like to follow the original idea. Here is the draft 
> agenda
> for our session:
>
> Session 1 (May 16, 14:00-15:30)
>
> AI 1.1. Report on Implementation Status of ADQL and SkyNode
>   I would like to ask the following people to talk (15 min each)
>     Martin Hill (UK)  -- ADQL
>     Wil O'Mullane (USA) -- ADQL, SkyNode
>     Yuji Shirasaki (Japan) -- ADQL, SkyNode in Java
>     Inaki Ortiz (Spain) -- SkyNode in Java
>
> (I note that we miss Hans-Martin Adolf (GAVO) in the Kyoto meeting,
> who implemented ADQL.)
>
> AI 1.2. Discussion if we can promote ADQL-0.9x and SkyNode 0.7x towards
>          Proposed Recommendations (20 min)
>
> Session 2 (May 17, 09:00 - 10:30) -- joint session with the DAL group
>
> AI 2.1. Experimental Integration of SIAP, SSAP and SkyNode through the
>    "Virtual Columns"
>    Yuji Shirasaki (Japan)  40 min
>
> AI 2.2. Discussion on Collaborative Work between VOQL and DAL
>              20 min
>
> AI 3. Any Other Business
>             15 min
>
> I would like to have comments, additions/deletions on the agenda items,
> and would like to confirm that suggested speakers on AI 1.1 can give
> their reports. Of course I welcome other speakers.
>
> See you in Kyoto very soon !!
>
> Cheers,
>
>      Masatoshi
>
>
> **********************************************
>                 Masatoshi  OHISHI
> National Astronomical Observatory of Japan
> 2-21-1, Osawa, Mitaka, Tokyo, 181-8588 JAPAN
> phone :+81-422-34-3575  (office)
>        +81-90-3574-9474 (mobile)
> fax   :+81-422-34-3840
> e-mail:masatoshi.ohishi at nao.ac.jp
> **********************************************
>
>
>

-- 
Dr. Hans-Martin Adorf . Max-Planck-Institut f. extraterrestrische Physik 
. Giessenbachstr. 1 . D-85741 Garching b. München . Germany
Phone: +49-89-30000-3352 . Fax: +49-89-30000-3404 . E-Mail: 
adorf at mpe.mpg.de . WWW: http://www.g-vo.org
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