(r4) Spectrum < IVOA

IVOA Web>IvoaDataModel>Spectrum (revision 4) (raw view)~~EditAttach~~
---+ Spectrum Data Model: version 1.2

<br />%TOC{depth="3"}%

---++ Goals

This update is to satisfy requested enhancements to the v1.1 model document.

Presentations by Vandana Desai
   * Nov. 2020 Interop: [[%PUBURL%/IVOA/InterOpNov2020DAL/Desai_IVOA_Presentation_18_Nov_2020.pdf][Implementation of the IVOA Spectral Data Model at IPAC” assessment of V1.1 Recommendation]]
   * May 2021 Interop: [[%PUBURL%/IVOA/InterOpMay2021DAL/Desai_IVOA_SpectralModel_2021.pdf]["IVOA Spectral Models and Access in the Era of Big Data”]] enhancement request to support IPAC use cases

---++ Participants

data modeler: MarkCresitelloDittmar

editor(s): MarkCresitelloDittmar

implementer(s):

   * Firefly: ???
      * Spectral plotter
   * CASSIS: ???
      * Spectral analyser
   * GAVO: ???
      * data provider

---++ Use Cases

The requests stem from visualization use cases:

<div title="Page 10">

   * 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.

</div>

---++ Discussion Threads

Preliminary meetings:

   * [[%PUBURL%/IVOA/InterOpMay2021DAL/IVOA_May21_DALDM_etherpad.txt][Interop DAL/DM Session - May 27, 2021]]
   * [[%PUBURL%/IVOA/IvoaDAL_RunningMeetings/IVOA_DAL_RM11_etherpad.txt][DAL/DM Running meeting - June 30, 2021]]
   * [[http://mail.ivoa.net/pipermail/dm/2021-October/006205.html][IVOA - Spectrum Data Model change request - Oct. 15, 2021]]

Planning meetings:

   * DM Meeting 20220622: [[DMRunning062022][Notes]]
Issue discussions:
   * [[http://mail.ivoa.net/pipermail/dm/2022-July/006262.html][UCDs assigment for new elements]] - Jul 21, 2022
   * [[http://mail.ivoa.net/pipermail/dm/2022-August/006273.html][UTypes in VOTable examples]] - Aug 18, 2022
   * [[http://mail.ivoa.net/pipermail/dm/2023-March/006369.html][Invalid UCDs in standard]] - Mar. 20, 2023

---++ 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" ==&gt; instr.saturation;phot.flux.density;stat.min"
            * upper limit: "The maximum flux of the source to remain undetected due to instrument sensitivity" ==&gt; 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 [[SpectrumDMUpdate][on this wiki page]]; it is partially resolved in V1.1 and should be closed out.

---++ Implementations

TBD

&lt;!--<br />      * Set ALLOWTOPICRENAME = IVOA.TWikiAdminGroup<br />--&gt;
Topic revision: r4 - 2023-04-27 - MarkCresitelloDittmar
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