Reference:
Version: 1.0
Author: ML with Data Model Working group
Date:

Documentation


Documentation

Preliminary specification

Overview of the application

This is an updated version for the Observation Data model Core components.

Goal: This modeling task aims at describing an Observation, with a set of structured metadata representing :
the observation content, the signal observed , the calibration status, quality assumptions etc...
These pieces of information are used in data discovery use-cases as stated in the Observation Core Components data model available at: http;//ivoa.net/DM/WD-ObsCoreDM-0.1-20110305.pdf
The model includes revisions and clarifications discussed at the Nara Interoprability meeting in December 2010 and iterations during the standard final discussions 2010-2011.

Spectrum Curation Target DataID SpaceTimeCoordinates CharacterisationDM Provenance Observation Photometry

Class diagram : Overview of packages used

This is a general View of the Observation DM.
The Core Components Observation data model will use only a subset of the classes required for most of the use-cases built-up,dor data discovery and retrieval.Classes from existing packages like
Characterisation or Spectrum( in white).
Colored packages are currently defined in the DM WG and will be developped
in coordination with this core model effort as well.

DataID Curation Target ObsConfig Detector ObservingElement Filter Facility Proposal Instrument Provenance Access CharacterisationAxis SpatialAxis SpectralAxis TimeAxis Characterisation Coverage Resolution Location Bounds Support ObservableAxis Accuracy Error ErrorRefVal ResolutionBounds ResolutionRefVal SamplingRefval Sampling CharacterisationDM Observation

Class diagram : Observation re-use of Characterisation interacts (1)

This class diagram covers all classes used in the context of the Observation Core components Model.
The Characterisation classes, describing how the data span along the main physical axes, are used
here partly, and only the attributes relevant to this modeling effort are shown here.
This is also the case for the DataID and Curation classes extended from the Spectrum/SSA data model.
The classes describing the physical axes of an observation contains the metadata used as search criteria when building a query.
We re-use the Characterisation data model down to the Support level (level4) .

Description of the SSA protocol:

http://www.ivoa.net/Documents/REC/DAL/SSA-20080201.html

CharacterisationAxis Characterisation PolarisationAxis ObservableAxis TimeAxis SpectralAxis FITS_WCS PolarisationMapping TemporalMapping SpectralMapping SpatialMapping SpatialAxis Observation

Class diagram : Mapping and WCS for an Observation

This diagram shows the information needed to compute world coordinates from the numerical values obteined along each characterisation axis.

Class diagram : Observation Types

Summary

It contains the following packages: It contains the following classes:

Use cases

Description

The defined use cases are: