STAC Catalog Navigation

Core Rule

Never conclude a dataset is missing until you have walked the full tree from the root catalog down.

Stopping at a sub-collection and declaring something absent is the primary failure mode.

Decoding STAC Browser URLs

The STAC Browser URL encodes the underlying JSON endpoint:

https://radiantearth.github.io/stac-browser/#/external/<S3-URL>

Fetch the <S3-URL> part directly. Example:

Browser URL: https://radiantearth.github.io/stac-browser/#/external/s3-west.nrp-nautilus.io/public-data/stac/catalog.json
Fetch:       https://s3-west.nrp-nautilus.io/public-data/stac/catalog.json

Navigation Order

1. Fetch ROOT catalog first
   → Walk ALL child links
   → Then walk into sub-collections as needed

2. If given a sub-collection URL, ALSO fetch its parent link
   → Never reason from a sub-collection alone

A dataset may be a child of the root catalog but NOT linked from a sub-collection — both are valid locations.

NRP Catalog Structure

• Root: https://s3-west.nrp-nautilus.io/public-data/stac/catalog.json
• High-seas sub-collection: public-high-seas/stac-collection.json (child of root)
• High-seas datasets may appear as direct children of the root OR as children of the sub-collection — check both before concluding anything

What to Fetch

Each STAC JSON has a links array. Relevant rel values:

Common Mistake

"The high-seas sub-collection only shows 4 datasets, so the others must be missing."

Wrong. The root catalog may link those datasets directly. Always check the root.

Quick Checklist

• Have I fetched the root catalog?
• Have I listed all child hrefs from the root?
• Did I check both the root AND any relevant sub-collection?
• Only after all of the above: conclude a dataset is present or absent