This folder contains profiles and extensions to the core SpatioTemporal Asset Catalog JSON specification.
Extensions are changes in functionality, that extend the core. This can include new JSON files that are linked to from
the core links, as well as new OpenAPI fragments.
Profiles specify additional fields outside the core STAC required items. Profiles should provide a sample Item, a
narrative explaining the fields and a JSON-Schema to validate compliance. Any data provider can create a profile, and
when providers work together to share fields between them they can create a shared profile and include it in the STAC
repository.
This directory includes an Earth Observation Profile. EO data is considered to be data that represents a snapshot of the earth for a single date and time. It could consist of multiple spectral bands in any part of the electromagnetic spectrum. Examples of EO data include sensors with visible, short-wave and mid-wave IR bands (e.g., the OLI instrument on Landsat-8), long-wave IR bands (e.g. TIRS aboard Landsat-8), as well as SAR instruments (e.g. Sentinel-1).
The profile provides common fields like cloud cover, off nadir, sun angle + elevation, gsd (ground sampled distance) and more. It also defines a way to explain what bands a sensor collects, and how to specify which bands are contained in an asset
The Collection Extension provides a way to specify data fields that are common across a 'collection'
of STAC Items, so that each does not need to repeat all the same information.