M2020 Imaging Data Archive Peer Review

Raw Data Product Archives

Sept — Oct, 2020

OVERVIEW & PURPOSE

For M2020, the majority of instruments acquire imaging data for either primary or secondary/context purposes — M2020 is festooned with imagers.  The data from all of these imagers will be processed through a unified Instrument Data System (IDS) pipeline to create operational image products for each of the instrument teams.  Therefore, this peer review will be an all-encompassing look at these operational imaging data.  Since these archives pertain to a rover mission that is not yet operating on the surface, this peer review will focus on the documentation, metadata and design/organization of the data products within the archives.  The actual image data are irrelevant at this time.  Further, this peer review is restricted to the suite of raw data products (historically referenced as EDRs), before any data reduction processing has been applied.  A separate peer review for the commensurate reduced/processed products (historically referenced as RDRs) will occur after this review.

There are 5 image archive “bundles” being reviewed here (see the Bundle SIS).  They are:

• mars2020_ecam: Navcam, Hazcam, EDLcam, CacheCam, (LVS)

https://pds-imaging.jpl.nasa.gov/reviews/mars2020/mars2020_ecam

• mars2020_mastcamz: Mastcam-Z

https://pds-imaging.jpl.nasa.gov/reviews/mars2020/mars2020_mastcamz

• mars2020_helicam: Helicopter cameras

https://pds-imaging.jpl.nasa.gov/reviews/mars2020/mars2020_helicam

• mars2020_imgops: SHERLOC, PIXL, and SuperCam cameras

https://pds-imaging.jpl.nasa.gov/reviews/mars2020/mars2020_imgops

• mars2020_meda: SkyCam

https://pds-imaging.jpl.nasa.gov/reviews/mars2020/mars2020_meda

As described in the Bundle SIS, the first four will ultimately be archived at the Imaging Node, with mars2020_imgops data being included by reference at the Geosciences node within the specific instrument bundles.  The last is archived at the Atmospheres note, and is a partial bundle containing only the SkyCam; it will be combined with the rest of the MEDA data in a single bundle.

OBJECTIVES

This peer review is being established to accomplish several important objectives:

1. Address the PDS requirement that data submitted to it for archival have passed a peer review
2. That the data are scientifically useful
3. That the metadata correctly and comprehensively describe the data
4. That the supporting documentation is complete and accurate
5. That the archive wholly complies with the PDS4 standards

Not all review members will be expected to comment with respect to all the above objectives.  Hopefully, the group as a whole will accomplish this.

Ultimately, your review of these archives will consist of a written set of comments, clarifications and discrepancies that, if implemented and/or corrected, would improve the archive.  These written statements need to be emailed to the Review Coordinator by the “Comments Due” date in the Schedule (below).

GETTING STARTED

Though this peer review covers a lot of data, there is a methodical path through it.  The first, and most important, thing to look at is probably the camera SIS.  The documents are the same in each of the 5 bundles so you can start here:

https://pds-imaging.jpl.nasa.gov/reviews/mars2020/mars2020_ecam/document/Mars2020_Camera_SIS.pdf

The SIS itself is huge, you are probably better off skimming it and honing in on sections of interest rather than trying to read the whole thing.  Of particular note are the label tables described in Appendix B, they describe in detail all of the label items.  Start with this one:

https://pds-imaging.jpl.nasa.gov/reviews/mars2020/mars2020_ecam/document/Mars2020_Camera_SIS_Labels_sort_pds.html

There’s also a PDF version, but the hyperlinks likely work better in the HTML.

Then it’s a matter of looking for the data you’re most interested in.  Pick a camera type, choose the right bundle from the above list, go to the directory starting with “data”, and drill down through the sol numbers to find the data of interest.  The XML label can be viewed directly in most Web browsers.  Cross-reference interesting items against the label table.

The browse directory contains viewable images, but given the nature of the data (see the lien list below), the images themselves are not that useful for review.  We tried to capture a wide variety of different data types.

DATA ACCESS

1. Possible interactive methods for perusing the imaging archives:

1. Directly interacting with the web site: you can simply go spelunking through the archive structures by clicking on the links.  This method is useful for deciphering the archive bundle structure.  It may also be the simplest way to examine the PDS4 labels.  Use the URL’s in the Overview for each bundle.
2. Browse image collections: each of the archive bundles contains a browse collection that contains representations of the data in easily rendered formats.  Since the data contents are irrelevant for this review, this will be of little use other than curiosity.

2. Some additional documents are provided outside the archives that may be helpful as part of your review.  These documents are not typically delivered within the archive bundles, but are necessary for making the archive bundles correct and useful.  Normally these will be delivered to PDS directly, but not all of them have been officially published yet.  If you wish to do your own PDS validation, you will need to use the supplied versions.  These are:

1. The Data Dictionaries that describe and enforce the schema for the metadata, and
2. The context products that are used to associate the metadata with certain objects (e.g., the planet Mars, the spacecraft Perseverance, the various instruments, etc…)

        All, however, are appropriate for your review.  They can respectively be found in:

https://pds-imaging.jpl.nasa.gov/reviews/mars2020/support/LDD/

https://pds-imaging.jpl.nasa.gov/reviews/mars2020/support/context/

LIENS/ERRATA/NOTES/COMMENTS

There are aspects of the archives submitted for this review that need to be exposed/expressed here to save reviewer time and/or focus reviewer attention.  Most are issues that the reviewer cannot resolve at this time.  However, for certain items (specifically #8) reviewer input is encouraged to help resolve the issue.  The current set of items are:

1. This is an EDR review, not an RDR review.  While comments on RDR sections of the SIS will be accepted, the RDR sections are not finished and reviewers should not spend a lot of time looking at them.
2. Some “EDR”         products are not presented here.  As mentioned above, this PR is billed as an "EDR" PR but in reality it's a "raw product" PR.  We are presenting/reviewing only the first-level images that are produced (typically ECM).  These are the only ones in the PDS4 "raw" category.  There are other images - decompanded (EDR and company) and debayered (EBY and company) - that are in the EDR category from the Operations team point of view, but because they require the RDR processing pipeline to produce, they are not included here.  They will be part of the "RDR" PR.
3. Not all aspects of the data are flightlike.  The data is a hodgepodge of images from ATLO and various testbeds, across a wide range of flight software versions, therefore not all aspects are flightlike. For example, very few of the images have enough information to successfully use SPICE, so things like solar azimuth and elevation may not appear in most images.  Some images have invalid or inconsistent data in their headers.  Only a few instruments have camera models.  This lack of consistent test data is a Project issue which is beyond the scope of discussion in this forum.  As a result, reviewers should look more at the format of the images and labels rather than the specific content (e.g. what the label names are, not so much the values).
4. Much of the data comes from testbed runs which use the DOY form of the filename, with a SOL containing an alpha first character.  For the purposes of this PR, these files are treated like a sol by just zeroing out the first character.  Thus a sol in the filename of "D074", which should be Day-Of-Year 74 in 2020 per the SIS, is treated as sol 0074 in this PR, and thus appears in the sol/00074 directory.
5. Labels are not completely finalized from the Project.  Expect minor additions as they continue to be fleshed out.  The intent is to not re-review minor additions or adjustments, but major changes may require a re-review.
6. There are a fair number of TBD’s in the Camera SIS document.  This is normal at this stage in flight project development.  Reviewers need not emphasize anything that is already marked TBD, but should think about what’s missing that is NOT marked TBD.
7. Some data types are scheduled for the RDR review.  The following types of data are not included in this review, and will be picked up in the RDR review:

1. LVS images (EDRs are not yet ready)
2. ECAM Microphone data
3. Movie files from EDL cameras
4. Single images extracted from the EDL movies
5. PLACES, Target Database, and Science Intent
6. SuperCam FITS-format images, which are a copy of the image with different metadata

8. Location of supporting documents is TBD.  Image calibration data and camera SIS documents MAY ultimately be delivered to a single Mars2020 documentation bundle with other bundles pointing to that as a "secondary collection" in order to avoid duplication, similar to how the images are secondary collections in the instrument bundles.  This is TBD and comments/opinions from reviewers are solicited.  For this review, the cal and doc files are duplicated in each bundle.
9. Calibration data is far from complete, what's there is just a snapshot of what we have now to show how it will look.  It includes a lot of testbed files that may or may not appear in the final cal collection.
10. All products are labeled version 00.  Normally versioning starts at 01. However, versioning is a function of the IDS pipeline, which was not used for the creation of these products, so they are all version 00 as assigned by the EDL generation program.
11. Portions of the Ops Keyword Table (Appendix B) will be deprecated.  Ignore the entries in the Ops Keyword Table (Appendix B) for Archive Attribute, X-path, and Reference (they're all marked TBD).  With the inclusion of the other keyword tables, these entries are no longer needed.  They just haven't been deleted from the document yet.
12. The documents for the review are PDF rather than PDF/A.  That will be fixed for the actual delivery.

SCHEDULE

REVIEWERS