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<font face="Times New Roman, Times, serif">Dear DM and Time Domain
followers,</font> <br>
<br>
<font face="Times New Roman, Times, serif">I am trying, together
with my CDS colleagues, to recap on the various DMs available in
the IVOA and understand the possible links between the future Time
Series Model ( as sketched in Jiris's Note) and existing DMs like
ND-Cube and STC 2.<br>
<br>
Here is a graph proposed by Laurent Michel to clarify the links in
3 main parts : <br>
</font>
<ul>
<li><font face="Times New Roman, Times, serif"><i>DataSetMetadata
DM</i>, which has the main ObsDataset Class ,</font></li>
<li><font face="Times New Roman, Times, serif"><i>ND-CubeDM</i>,
which defines a SparseCubedataset</font></li>
<li><font face="Times New Roman, Times, serif"><i>TimeSerieCubeDM</i>,
which highlights the special properties of a Cube depending on
a Time axis</font></li>
</ul>
<font face="Times New Roman, Times, serif">I think this is essential
to highlight the inheritance path between these 3 DM building
blocks: <br>
a TimeSeriesCube <is a > NDCubeDM::SparseCubeDataset<br>
</font>a <font face="Times New Roman, Times, serif"><font
face="Times New Roman, Times, serif"><font face="Times New
Roman, Times, serif"> NDCubeDM::</font>SparseCubeDataset </font></font><font
face="Times New Roman, Times, serif"><is a >
DatasetMetadaDM::ObsDataset<br>
</font><br>
<font face="Times New Roman, Times, serif"><font face="Times New
Roman, Times, serif">ObsDataset has a <i>dataproduct</i><i>_</i><i>type</i>
attribute which allows to discover all dataproducts of type '
timeseries'. <br>
this provides the container object for time-dependent data.<br>
<br>
If we need to select <i>timeseries dataproducts</i> according
to some properties extracted from their data we can:<br>
- reuse what <font face="Times New Roman, Times, serif">Obscore
DM provides to explain general axes properties<br>
</font></font></font><font face="Times New Roman, Times, serif"><font
face="Times New Roman, Times, serif"><font face="Times New
Roman, Times, serif"><font face="Times New Roman, Times,
serif"><font face="Times New Roman, Times, serif">target_<font
face="Times New Roman, Times, serif">name</font>,
s_region, </font></font><font face="Times New Roman,
Times, serif"><font face="Times New Roman, Times, serif"><font
face="Times New Roman, Times, serif"><font face="Times
New Roman, Times, serif">s_resol, </font></font>t_min,
t_max, t_resol, em_min, em_max, em_resol, etc. are the
basic properties for discovery<br>
<br>
</font></font> </font>- provide a richer description of the
<font face="Times New Roman, Times, serif">T</font>imeAxis a<font
face="Times New Roman, Times, serif">nd Observa<font
face="Times New Roman, Times, serif">ble<font face="Times
New Roman, Times, serif">Axis</font></font></font>. <br>
For that , extracting a statistical profile from the data
contained in the Cube could do the job. <br>
<font face="Times New Roman, Times, serif">this means to </font>access
and analyse the Data part in ND-Cube , i. e the ND-Points
gathered in a SparseCube Object<br>
</font></font><font face="Times New Roman, Times, serif"><font
face="Times New Roman, Times, serif"><br>
I guess more properties can be exposed to qualify the axes
present in the Timeseries dataset , but for the moment , I see
some overlap of notions between <br>
CharacterisationDM::ObservableAxis, STC2.0::CoordMeasurement
(??) and TimeSerieCubeDM::CubeAxis.<br>
<br>
This would be great if we could sort this out, <br>
but currently , I would appreciate your feedback on the attached
diagram , in order to proceed on the data model structure. <br>
<br>
Cheers, Mireille ( after discussions together with Laurent,
François, Ada) <br>
<br>
</font></font>
<pre class="moz-signature" cols="72">--
--
Mireille Louys
CDS Laboratoire Icube
Observatoire de Strasbourg Telecom Physique Strasbourg
11 rue de l'Université 300, Bd Sebastien Brandt CS 10413
F- 67000-STRASBOURG F-67412 ILLKIRCH Cedex
tel: +33 3 68 85 24 34</pre>
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