<html><head><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div><br></div><div>Dear François,</div><div><br></div><div>I would strongly endorse your proposal to have demonstrations of real implementations of the multi-d data standards. </div><div><br></div><div>From the CSP point of view we absolutely need to converge on this first set of multi-d data standards and show that they work.</div><div><br></div><div>The minimal requirements were set from the scientific priorities for multi-dimensional data access, and this led to a set of standards that needed to be developed to address those requirements. This has been an important way of ensuring that those standards do what is needed and the requirements were used to keep the scope under control. This worked well for the SIAv2.0, ObsCore and DataLink standards and even though the process has been long, the emergence of serious implementations of these for data cube access is an important success. </div><div><br></div><div>I would hope that the Access Data now SODA standard, whose role with respect to the minimal requirements is to enable simple cut-outs, would have the same level of management applied to make it converge. Especially after all of the many difficult and hard won compromises and agreements. As new ideas are proposed, I would expect these to be put into a future version and any features outside the minimal requirements should not impact the process. These standards must really be allowed to be finalised.</div><div><br></div><div>regards,</div><div>Mark Allen</div><div><br></div><div><br></div><br><div><div>On 3 Mar 2016, at 16:45, François Bonnarel <<a href="mailto:francois.bonnarel@astro.unistra.fr">francois.bonnarel@astro.unistra.fr</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">
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Last of my three emails of today,<br>
<br>
Let me make a proposal to the DAL community and to data providers
willing to expose data Cubes (dim >= 3) in the VO.<br>
<br>
The idea is to try to realize the basic scenario described in
the CSP requirement by using SIAV2 or OBstap implementations, as
well as DataLink and the current version of SODA spec. This should
be operated on real cubes ( 2D images or spectra would not be
considered as good validation) and it's not necessary to demonstrate
additional (more sophisticated ) server side operations. Additional
specifications for Domain metadata or subtilities in pathes to SODA
or DataLink use can be added and should be described but the
prototyping should clarify what they really add to the use case
realisation. <br>
Demonstrations of implementations or prototypes should occur in
DAL session at Cape Town. Contact me if you want to participate and
make a demo in Cape Town.<br>
<br>
The CSP requirements can be found below.<br>
I consider that CADC new SODA version is the first of those
test implementations for Cape Town <br>
<br>
<br>
Cheers<br>
François <br>
<br>
CSP requirements <br>
<br>
a ) Data Discovery (Query) <br>
A service shall return to the client a list of observations, and <br>
the corresponding metadata for each observation, meeting the <br>
user imposed constraints. In the event that the user places no <br>
constraints, the entire list of observations, and the correspondin <br>
metadata for each data set, shall be returned. In the event that no
<br>
data meet the user's constraints, the service shall indicate the <br>
absence of any matches. <br>
<br>
<br>
b ) Data Access <br>
* Once a user has the list of observations that satisfy the <br>
constraints, they select all or a subset of the observations and: <br>
* Download the complete science data for each of the <br>
selected observations (the service shall return the complete <br>
multidimensional science data and metadata for each selected <br>
observation) or; <br>
* Download simple cutouts of the science data for each of the <br>
selected observations (the service shall be able to extract and <br>
return a user specified subset of the complet <br>
e multidimensional <br>
science data and metadata for each selected observation). <br>
<br>
<br>
Simple Cutout <br>
* For a simple cutout, the user specified subset is restricted to <br>
be a contiguous interval within each dimension of the
multidimensional science data. <br>
The user should <b class="moz-txt-star"><span class="moz-txt-tag">*</span>not<span class="moz-txt-tag">*</span></b> be allowed to specify subsets
with "gaps" or resampling or anything like that. <br>
* Spatial: a circle (a coordinate and a radius) <br>
* Energy: one interval (from energy1 to energy2) <br>
* Time: one interval (from time1 to time2) <br>
* Polarization: a list <br>
<br>
<pre class="moz-signature" cols="72">--
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François Bonnarel Observatoire Astronomique de Strasbourg
CDS (Centre de données UMR 7550 CNRS / Université de Strasbourg
astronomiques de Strasbourg) 11, rue de l'Université
F--67000 Strasbourg (France)
Tel: +33-(0)3 68 85 24 11 WWW: <a class="moz-txt-link-freetext" href="http://cdsweb.u-strasbg.fr/people/fb.html">http://cdsweb.u-strasbg.fr/people/fb.html</a>
Fax: +33-(0)3 68 85 24 25 E-mail: <a class="moz-txt-link-abbreviated" href="mailto:francois.bonnarel@astro.unistra.fr">francois.bonnarel@astro.unistra.fr</a>
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Mark Allen<br><a href="mailto:mark.allen@astro.unistra.fr">mark.allen@astro.unistra.fr</a><br>
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