Collection links for catalogs/collections

[m-mohr]

I'm currently experimenting with collection links in non-Items. I think there can be value in having them.

Example implementation: https://radiantearth.github.io/stac-browser/#/external/raw.githubusercontent.com/m-mohr/open-stac/3d-skysat/stac/open-skysat-data/cocabamba-peru/catalog.json

Having an easy way to navigate back to the next collection in the (potentially long) list of parents may help navigation.

Let's say you have a structure as such:

• Root
  • ESA (collection)
    • Sentinels (catalog)
      • Sentinel-1 (catalog)
      • Sentinel-2 (catalog)
        • Level 1A (collection)
          • 2020 (catalog)
            • Jan (catalog)
              • 01 (catalog)
                • 12345 (item)
                • 67890 (item)
                • ...
              • 02 (catalog)
              • 03 (catalog)
              • ...
            • Feb (catalog)
            • Mar (catalog)
            • ...
          • 2021 (catalog)
          • 2022 (catalog)
        • Level 2A (collection)
        • Level 2B (collection)
    • Others (catalog)
  • NASA (collection)

I think there should be easy ways without following multiple parent links up to the collection, e.g. for easy navigation from Level 1A to ESA or 01 to Level 1A. Thus my proposal is to also allow links with rel collection explicitly also in Catalogs and Collections. Currently it's only defined for Items.

Disclaimer: This is just an example for better understanding, it doesn't matter here whether ESA is a good or bad Collection. It could be something different.

[PowerChell]

Note: one of the most common questions Matthias gets. High Priority.