| name | stac-navigation |
| description | Use when browsing, querying, or reasoning about what datasets exist in a STAC catalog — especially before concluding a dataset is missing or absent. Triggers include STAC browser URLs, s3 stac-collection.json links, or any question about what data is available in a catalog. |
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:
| rel | Meaning |
|---|
root | Top-level catalog — always fetch this first |
parent | Walk up if you started mid-tree |
child | Walk down to find datasets |
item | Leaf-level data asset |
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
