The SpatioTemporal Asset Metadata spec aims to standardize common fields to search remotely-sensed imagery and other geospatial assets. It is a complementary specification to the SpatioTemporal Asset Catalog - indeed most every item of those catalogs will expose its SpatioTemporal Asset Metadata.
The metadata fields are selected primary for search, and cross-catalog compatibility. In time a set of 'extensions' will emerge to better specify and search certain types of assets, but the main goal is to enable a baseline of standardization. Providers of imagery are also able to extend to the fields they care about.
This repository contains the 'abstract' specification of the core fields and their explanation. The JSON specification is currently being evolved in the stac-spec repo, so that it stays in line with the catalog as a whole. This repo is maintained independently to emphasize that the core fields can be re-used in other contexts, like potentially embedded in GeoTIFFss, so that cloud optimized geotiffs can be more self-describing. So the repo may lag a bit behind the latest.
This work started as the Open Imagery Network Metadata spec, but is evolving to be more generic and flexible. Ideally the OIN metadata spec will simply be a compatible version of this metadata, with a constraint that data license must be a single, open data license. Additional work on the spec was done at the stac boulder sprint
All contributions should be done with pull requests, and should be informed by real, working software.
abstract-spec.md contains the core fields and their explanations.