Recap of your meeting with Radiant Earth Foundation

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Feb 23, 2026, 12:00:45 PM (4 days ago) Feb 23

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Meeting Purpose Sync on STAC community projects and discuss new tools. Key Takeaways - PySTAC V2 will modularize extensions into separate libraries, enabling independent versioning and external maintenance to reduce core project burden. - NOSTAC, a new U.S. federal project, uses semantic tech to build dynamic, interoperable STAC indexes, addressing a key government need to break down data silos. - STACFactory is a strict Pydantic-based tool for writing valid STAC, designed to prevent common errors (e.g., flipped BBOX coordinates) that current JSON Schema validation misses. - STAC Browser V5 is in development, focusing on internal stability via new tests and validator updates, following the final V4 release. Topics STAC Validation & Writing Tools - Problem: Current STAC JSON Schemas are too permissive, failing to catch common, easily preventable errors in catalogs. - Example: A recent crawl of 100k collections found an "insane" number of invalid entries. - Solution → STACFactory: A new tool for writing STAC objects with highly validated Pydantic models. - Goal: Provide strict, range-bounded validation (e.g., latitude must be -90 to 90) to ensure objects are valid at construction. - Rationale: This contrasts with PySTAC's permissive read/write model, which must be flexible to parse existing data. - Status: Development paused in May; could be used to rewrite StackTools or integrate with PySTAC for strict writing. PySTAC V2 Development - Status: Julia Signell is working on porting V1 tests to V2 and fixing CI to enable file-by-file debugging. - Key Architectural Change: Extensions will become separate Python libraries. - Rationale: This non-breaking change solves versioning and maintenance challenges. - Benefits: - Independent Versioning: Extensions can release on their own schedule. - Multi-Version Support: PySTAC can use the correct extension version for a given STAC object. - External Maintenance: Reduces the maintenance burden on the core PySTAC team. NOSTAC: Semantic STAC for the U.S. Government - Project: NOSTAC (Knowledge Interoperable STAC), a U.S. federal initiative led by Justin Lewis. - Goal: Use semantic web tech to build dynamic, semantically described STAC indexes, breaking down data silos. - Status: First production release was two weeks ago; now gathering feedback and fixing bugs. - Future Focus: Developing standards for interoperable STAC indexes beyond the core spec, including defining additional attributes and bridging tools. STAC Browser V5 Development - Status: Matthias Mohr released STAC Browser V4.0.1 (the final V4 version) and is now rebuilding V5 internally. - V5 Focus: Improving stability by adding more tests. - Related Updates: - STAC.js: Updated to support V5 development. - STAC Node Validator: Updated to support V5 development. - Community Feedback: Matthias is seeking feedback on a new vector extension and a PR to rework the table extension. Next Steps - Michelle Roby: Schedule the next STAC PSC call. - Phil Varner: Share the STACFactory link. - Matthias Mohr: Continue V5 development; seek feedback on vector and table extensions. - Justin Lewis: Continue NOSTAC development; focus on interoperability standards. - Julia Signell: Continue PySTAC V2 development.