Role of data models in the Virtual Observatory, and overview of IVOA data models. Part of the virtual observatory course by Juan de Dios Santander Vela, as imparted for the MTAF (Métodos y Técnicas Avanzadas en Física, Advanced Methods and Techniques in Physics) Master at the University of Granada (UGR).

1. VO, Data Models, and
VO Archives
Juan de Dios Santander Vela (IAA-CSIC)

2. Overview
Data Model Definition
IVOA and Data Modelling
Radio Astronomy DAta-Model for Single-dish

3. Data Models

4. Data Model Definition
Complete description of the set
of entities needed for
information storage in a
particular field, which specifies
both the data being stored, and
the relationships between them.

5. Information Structure
JUAN DE DIOS SANTANDER VELA
JDSANT@IAA.ES
INSTITUTO DE ASTROFÍSICA DE ANDALUCÍA (CSIC)
BECARIO I3P DE POSTGRADO (01/2006-12/2006)
BECARIO PREDOCTORAL IAA (03/2005-12/2005)

6. Information Structure
JUAN DE DIOS SANTANDER VELA
JDSANT@IAA.ES
INSTITUTO DE ASTROFÍSICA DE ANDALUCÍA (CSIC)
BECARIO I3P DE POSTGRADO (01/2006-12/2006)
BECARIO PREDOCTORAL IAA (03/2005-12/2005)

7. Information Structure
JUAN DE DIOS SANTANDER VELA
JDSANT@IAA.ES
INSTITUTO DE ASTROFÍSICA DE ANDALUCÍA (CSIC)
BECARIO I3P DE POSTGRADO (01/2006-12/2006)
BECARIO PREDOCTORAL IAA (03/2005-12/2005)

8. Information Structure
JUAN DE DIOS SANTANDER VELA
JDSANT@IAA.ES
INSTITUTO DE ASTROFÍSICA DE ANDALUCÍA (CSIC)
BECARIO I3P DE POSTGRADO (01/2006-12/2006)
BECARIO PREDOCTORAL IAA (03/2005-12/2005)

9. Information Structure
JUAN DE DIOS SANTANDER VELA
JDSANT@IAA.ES
INSTITUTO DE ASTROFÍSICA DE ANDALUCÍA (CSIC)
BECARIO I3P DE POSTGRADO (01/2006-12/2006)
BECARIO PREDOCTORAL IAA (03/2005-12/2005)

10. Information Structure
JUAN DE DIOS SANTANDER VELA
JDSANT@IAA.ES
INSTITUTO DE ASTROFÍSICA DE ANDALUCÍA (CSIC)
BECARIO I3P DE POSTGRADO (01/2006-12/2006)
BECARIO PREDOCTORAL IAA (03/2005-12/2005)

11. Information Structure
JUAN DE DIOS SANTANDER VELA
JDSANT@IAA.ES
INSTITUTO DE ASTROFÍSICA DE ANDALUCÍA (CSIC)
BECARIO I3P DE POSTGRADO (01/2006-12/2006)
BECARIO PREDOCTORAL IAA (03/2005-12/2005)

12. Information Structure
JUAN DE DIOS SANTANDER VELA
JDSANT@IAA.ES
INSTITUTO DE ASTROFÍSICA DE ANDALUCÍA (CSIC)
BECARIO I3P DE POSTGRADO (01/2006-12/2006)
BECARIO PREDOCTORAL IAA (03/2005-12/2005)

13. Information Structure
JUAN DE DIOS SANTANDER VELA
JDSANT@IAA.ES
INSTITUTO DE ASTROFÍSICA DE ANDALUCÍA (CSIC)
BECARIO I3P DE POSTGRADO (01/2006-12/2006)
BECARIO PREDOCTORAL IAA (03/2005-12/2005)

14. Information Structure
JUAN DE DIOS SANTANDER VELA
JDSANT@IAA.ES
INSTITUTO DE ASTROFÍSICA DE ANDALUCÍA (CSIC)
BECARIO I3P DE POSTGRADO (01/2006-12/2006)
BECARIO PREDOCTORAL IAA (03/2005-12/2005)

15. Information Structure
JUAN DE DIOS SANTANDER VELA
JDSANT@IAA.ES
INSTITUTO DE ASTROFÍSICA DE ANDALUCÍA (CSIC)
BECARIO I3P DE POSTGRADO (01/2006-12/2006)
BECARIO PREDOCTORAL IAA (03/2005-12/2005) NT
E
E ND
D EP
D EL
MO
D ATA

16. Information Structure
Data model elements
Fields (Attributes in OOP, XML)
Data types
Semantics
Relationships

17. Information Structure
ATTRIBUTES & DATA TYPES
Field Object Number Source RA Dec Epoch
Data Type BigInt String Float Float String Code
Example 3123453445 ‘CIG 96’ 132.3478 -05.3345 ‘J2000’
Data OBGGALAX_1 96 8h12º50’52’’ -0h5º20’42’’ ‘Epoch J2000’

18. Information Structure
SEMANTICS & UCDS
Object
Field Source RA Dec Epoch
Number
Object Right
Meaning Source name Declination Epoch code
identifier Ascension
meta.id; meta.id; pos.eq.ra; pos.eq.dec; time.epoch;
UCD
meta.code meta.name meta.main meta.main meta.code

19. Elements of a DM
Entities Cardinalities
Data model building
Data types
blocks
Grouping of related Units
attributes
Semantics
Fields via UCDs & UTypes
Actual data elements of
the model
Relationships
Between attributes in
different Entities

20. Data Model Roles
Discovery
Evaluation
Data Access
Transformation

21. Data Model Roles
Discovery
Evaluation
Data Access
Transformation

22. IVOA Data Modelling

23. IVOA Data Modelling

24. IVOA Data Modelling

25. IVOA Data Modelling

26. IVOA Data Modelling

27. IVOA Data Modelling

28. Observation Data Model
Independent
of observation
Dependent data reduction Observation
ObsData Characterisation Target Curation Provenance
Observing
Coverage Resolution Precision Processing
Configuration
Location Support Sensitivity
F T Observing
Elements
Calibration
R A
D

29. Observation Data Model
Independent
of observation
Dependent data reduction Observation
ObsData Characterisation Target Curation Provenance
Observing
Coverage Resolution Precision Processing
Configuration
Location Support Sensitivity
F T Observing
Elements
Calibration
R A
D

30. Characterisation DM
Figure 4: The layered structure of Characterisation: This diagram synthe-
sises the Property/Axis/Layer approach. The concepts are represented in yel-

31. Characterisation DM:
Errors
Figure 5: This class diagram illustrates the CharacterisationAxis class and
its relationship with the Accuracy class, which encompasses various types of

32. Spectral Data Model
Spectrum
Target Data Characterisation CoordSys Curation DataID Derived

33. Spectral DM: Data
Data
n
Background
DataAxis FluxAxis Model
ucd TimeAxis
unit
SpectralAxis
1,..SegmentSize
Accuracy Resolution
Value Quality
value,unit
StatError SysError BinSize
BinLow
StatErrLow StatErrHigh BinHigh
Figure 2: Diagram for Data object

34. StatError SysError BinSize
Spectral Characterisation
BinLow
StatErrLow StatErrHigh BinHigh
Figure 2: Diagram for Data object
Characterization
n
CharacterizationAxis FluxAxis
SpatialAxis
name
ucd
TimeAxis
unit
SpectralAxis
Accuracy Resolution
Coverage
value,unit
StatError SysError BinSize
Bounds Support
Location
value
Calibration
Extent Start Area Fill
Stop
8
Figure 3: Diagram for Characterization object

35. Space-Time Coordinates

37. Radio Astronomy DAta-
Model for Single-dish

38. RADAMS’ Sources
Data Model for Observation
McDowell, Bonnarel et al., IVOA Data Model WG Internal Draft
Data Model for Astronomical Dataset
Characterisation
McDowell, Bonnarel et al., IVOA Data Model WG Note
IVOA Spectral Data Model
McDowell, Tody et al., IVOA Data Model WG Working Draft
IVOA Data Model for Raw Radio Telescope Data
Lamb and Power, IVOA Radio IG Note

39. RADAMS Structure
Observation Curation
ObsData
Policy
Characterization Provenance Target Packaging
Coverage Resolution Precision Sensitivity
Accuracy

40. RADAMS Structure
Data Model for Observation Observation Curation
ObsData
Policy
Characterization Provenance Target Packaging
Coverage Resolution Precision Sensitivity
Accuracy

41. RADAMS Structure
Observation Curation
ObsData
Policy
Characterization Provenance Target Packaging
Coverage Resolution Precision Sensitivity
Accuracy Data Model for
Dataset
Characterisation

42. RADAMS Structure
Observation Curation
ObsData
Policy
Characterization Provenance Target Packaging
Coverage Resolution Precision Sensitivity Undefined Data Models
Accuracy

43. RADAMS Detail
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