Description
DMS-REQ-0043 says, in the normative text:
Specification: The DMS shall provide calibrated photometry in each observed passband for all measured entities (e.g., DIASources, Sources, Objects), measuring the AB magnitude of the equivalent flat-SED source, above the atmosphere. Fluxes, possibly in jansky, shall be calculated for all measured entities. [emphasis mine]
This text should have been corrected as part of LCR-1459, "Update Data Products Definition Document LSE-163", which included the adoption of a PST recommendation ( Document-27758 ) to report fluxes in nanojanskys.
It is proposed to change the normative text of DMS-REQ-0043 to the following:
Specification: The DMS shall provide calibrated photometry in each observed passband for all measured entities (e.g., DIASources, Sources, Objects), measuring the AB magnitude of the equivalent flat-SED source, above the atmosphere. Fluxes shall be calculated for all measured entities, and shall be reported in nanojanskys.
and to append the following sentence to the "Discussion" section:
The rationale for the use of nanojanskys is presented in Document-27758.
Following approval of this RFC, an LCR will be required to actually change the DMSR.
Attachments
Issue Links
- is triggering
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DM-25715 Submit an LCR on LSE-61 to carry forward RFC-702
- Done
- links to
Activity
I support this RFC
+1
As someone involved in the original jansky/maggie/nanojansky discussion, I wholehearted approve of this RFC.
In the course of researching another RFC, I came across DMS-REQ-0347, "Measurements in catalogs", in the "General Considerations" for "Data Products" section (1.1) of the DMSR:
All catalogs shall record source measurements in flux units.
Requirement DMS-REQ-0043, by contrast, appears in the "Applications Software" section.
It seems more appropriate to constrain the units in a requirements section related to the presentation of data products, so on reflection I would like to revise my proposal as follows:
- The normative text of DMS-REQ-0043 should end with the sentence "Fluxes shall be calculated for all measured entities." with no change to the existing Discussion.
- DMS-REQ-0347 should be changed to state "All catalogs shall record source measurements with fluxes, reported in nanojanskys." with "The rationale for the use of nanojanskys is presented in Document-27758." appended to the Discussion.
Moved to "Adopted"; DM-25716 for implementation (in this case, filing an LCR).
LCR-2378, "Correct LSE-61 Flux Units Definition to Nanojanskys", submitted.
I think this LCR has been fully implemented and this RFC can also be marked implemented.
It has, yes
This looks good to me. I'm happy to fast track this RFC and discuss it at tomorrow's DMCCB meeting.