Spectrum Data Model: version 1.2
Goals
This update is to satisfy requested enhancements to the v1.1 model document.
Presentations by Vandana Desai
Participants
data modeler:
MarkCresitelloDittmar
editor(s):
MarkCresitelloDittmar
implementer(s):
- Firefly: ???
- CASSIS: ???
- GAVO: ???
Use Cases
The requests stem from visualization use cases:
- 1-D spectra from Spitzer’s Infrared Spectrograph have multiple spectral orders
- Spectral orders can overlap in wavelength
- Plotting a Spitzer spectrum without accounting for orders gives you a mess
- SEDs often include limits on measurements
- these can be upper or lower limits
- Plotters need to indicate limits clearly to avoid scientific misunderstanding
- SDM1.1 has an ad-hoc representation for upper limits (only) which may be usable, but is conceptually incorrect.
Discussion Threads
Preliminary meetings:
Planning meetings:
- DM Meeting 20220622: Notes
Issue discussions:
Data Model Updates
The document is being updated in the IVOA Git repository
SpectrumDM: branch wd-v1.2: (
https://github.com/ivoa-std/SpectrumDM/tree/wd-v1.2)
- Migration to Git - preparatory work
- port Spectrum 1.1 REC document files to model repository
- tag release (REC-V1.1-20111020)
- create branch for RFE
- restructure repository content to match other models
- migrate model diagrams to proper UML
- improve consistency with schema and description
- List of Changes:
- 2022 Jun 22: Document reset to WD for enhancement
- 2022 Jul 19: Add spectral order elements
- 2022 Jul 20: Add upper/lower limit elements
- 2023 Mar 17: Correct case for order and relorder attributes to match spec.
- 2023 Apr 27: Correct UTypes in VOTable example 1; assign UCDs for upper/lower limits
- Open Issues:
- #5: UCD assignment (resolved?)
- selection of UCDs for the new elements had no clear resolution within the working group
- last question of the discussion thread really sums it up
- "are we talking about the upper/lower limits of the instrument or the source? Both are related, but the interpretation is different"
- based on this discussion I have (tentatively) employed the following definitions
- lower limit: "The minimum flux of the source due to instrument saturation" ==> instr.saturation;phot.flux.density;stat.min"
- upper limit: "The maximum flux of the source to remain undetected due to instrument sensitivity" ==> instr.sensitivity;phot.flux.density;stat.max"
- #7: Invalid UCD in standard
- Review and discussion of DaCHs serializations identified several UCDs in the current REC which are invalid.
- Discussion for Issue #5 identified some other actions which could be taken to improve the existing UCDs
- Update UCD Vocabulary Reference is Section 3.4
- Add tags which enable validation of UCDs contained in teh document (during build)
- There is a UCD RFE documented on this wiki page; it is partially resolved in V1.1 and should be closed out.
Implementations
TBD
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