Design and integrate in the viz-workflow a service to auto generate STAC

[alonakos]

This issue is opened to track progress and facilitate discussion around implementing STAC catalog generation as part of the PDG visualization workflow. Previous related ticket: #25 [here]

Details

We recently implemented a WMTSCapabilitiesGenerator to automatically generate a WMTSCapabilities.xml document during the workflow execution. See implementation here. The next step is to define and integrate a corresponding STAC catalog.

Open Questions and Design Decisions

• STAC Asset Representation:
  Each output format for a layer (e.g., PNG tiles, GeoTIFF, GeoPackage) should be modeled as a separate STAC asset.
  TBD: Decide on naming conventions.

• Catalog vs. Collection Structure:
  Will we have a single top-level catalog representing the entire PDG portal, or should we simplify and start directly from collections?

• Collection Options:
  Option 1: Collections represent portals (e.g., PDG, QGreenland).
  Option 2: Collections represent thematic groups of layers (e.g., People, Lakes & Surface Water, Permafrost, Carbon)
  Option 3: Collections represent one layer

• UI Integration:
  Where should we surface the link to the static STAC catalog or API?

[alonakos]

@robyngit @mbjones @regetz I created this to facilitate the discussion. I will do more research on the use cases, wanted to ping you here if you have any thoughts or ideas to add.

[alonakos]

Some updates on this ticket, because a lot of research/discussion have been done:

• QGIS STAC plugin does not support static STAC catalogs.json/collections.json, and needs an API service.
• Newer QGIS builds now expose a native “STAC” option in Data Source Manager, but I have not yet been able to load public static catalogs successfully. Unclear whether native STAC supports static catalogs or expects an API endpoint as well.
• It seems like the best path forward is for us to host a one top-level catalog.json (that serves as a root) for the whole portal (like PDG). Have a dataset/layer family to be represented by collection.json and items to be each year of the given dataset, and assets are a WMTS tileset or GeoTIFF mosaic for one product and time slice.

[mbjones]

@alonakos let's discuss this design on one of our dev meetings next week with @rushirajnenuji and the other devs who are working on back end services. A dynamic STAC catalog is not out of the question, but we'd need to thingk carefully about how it fits into our data storage plans.