DRP plans for archiving and serving coadds to users have changed. Only per-band deep coadds will be archived. All other flavours of coadds, if generated by DM, will not be archived, rather, DM will provide the software, metadata and provenance information necessary for end users to generate them on demand

The DPDD is being updated to bring it in line with these plans in DM-23248. The following specific changes are also needed to the DMSR:

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1.4.1 Persisting Data Products
ID: DMS-REQ-0334 (Priority: 1b)

Specification: All per-band deep coadds and best seeing coadds shall be kept indefinitely and made available to users.

Discussion: This requirement is intended to list all the data products that must be archived rather than regenerated on demand. DMS-REQ-0069 indicates in discussion that Processed Visit Images are not archived. DMS-REQ-0010 indicates in the discussion that Difference Exposures are not archived.

Change to

ID: DMS-REQ-0334 (Priority: 1b)

Specification: All per-band deep coadds shall be kept indefinitely and made available to users.

Discussion: This requirement is intended to list all the data products that must be archived rather than regenerated on demand. DMS-REQ-0069 indicates in discussion that Processed Visit Images are not archived. DMS-REQ-0010 indicates in the discussion that Difference Exposures are not archived.

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1.4.7 Multi-band Coadds

ID: DMS-REQ-0281 (Priority: 1b)

Specification: The DMS shall periodically create Multi-band Coadd images which are constructed similarly to Deep Detection Coadds, but where all passbands are combined.

Discussion: The multi-color Coadds are intended for very deep detection.

Change to

ID: DMS-REQ-0281 (Priority: 1b)

Specification: The DMS shall periodically create Multi-band Coadd images which are constructed similarly to Deep Detection Coadds, but where all passbands are combined. These Coadds will not be archived.

Discussion: The multi-color Coadds are intended for very deep detection. DM will provide software, metadata and provenance information sufficient to allow these coadds to be recreated on-demand by end-users.

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1.4.8 Best Seeing Coadds
ID: DMS-REQ-0330 (Priority: 2)

Specification: Best seeing coadds shall be made for each band (including multi-color).

Discussion: DMS-REQ-0279 states that seeing-based co-adds should be possible. This requirement states that they shall be made.

Change to

ID: DMS-REQ-0330 (Priority: 2)

Specification: Best seeing coadds shall be made for each band (including multi-color). These Coadds will not be archived.

Discussion: DMS-REQ-0279 states that seeing-based co-adds should be possible. DM will provide the software, metadata and provenance information necessary to allow these coadds to be recreated on-demand by end-users.
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1.4.9 PSF-Matched Coadds
ID: DMS-REQ-0335 (Priority: 1b)

Specification: One (ugrizy plus multi-band) set of PSF-matched coadds shall be made but shall not be archived.

Discussion: These are used to measure colors and shapes of objects at "standard" seeing. Sufficient provenance information will be made available to allow these coadds to be recreated by Level 3 users.

Change to

ID: DMS-REQ-0335 (Priority: 1b)
Specification: One (ugrizy plus multi-band) set of PSF-matched coadds shall be made but shall not be archived.

Discussion: These are used to measure colors and shapes of objects at "standard" seeing. DM will provide software, metadata and provenance information sufficient to allow these coadds to be recreated on-demand by end-users.