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1. Introduction#
This document provides server implementation best practices for SpatioTemporal Asset Catalog (STAC) search and catalog services that allow for standardized and harmonized access to metadata and data for CEOS agencies, including CWIC and FedEO.
STAC is a lightweight, JSON-based language that is asset-oriented, self-navigable and tailored towards the spatial and temporal domain.
It also provides a framework for achieving federated discovery in much the same way as OpenSearch. Where STAC has an advantage over OpenSearch is its widespread adoption in the earth science informatics community.
1.1 Purpose of document#
The STAC ecosystem comprises both API-related and metadata-related specifications. This document provides server implementation Best Practices for STAC-based metadata publication and related discovery services allowing for standardized and harmonized access to metadata and data for CEOS agencies.
The purpose of this document is to achieve the following,
Promote the use of the STAC standard as a means of data discovery for Earth Data providers
Define the expectations and requirements of candidate STAC implementations
Remove ambiguity in implementation where possible
Facilitate the aggregation of results between disparate Earth Data providers via STAC common standards
Allow for clients to access search engines via STAC capabilities with no a priori knowledge of specific implementations
Facilitate smooth integration between related STAC implementations, such as a dataset resource collection that refers to granule resource collections from another provider
Replace the existing CEOSS WGISS Integrated Catalog (CWIC) and WGISS Connected Data Assets (CDA) infrastructure, based on the OpenSearch API, with the STAC API and STAC catalogs
1.2 Document overview#
The document is organized as follows:
Chapter 1 is the introduction of the document.
Chapter 2: Objectives and needs gives an overview of objectives and needs.
Chapter 3: Best Practices introduces the categories of Best Practices and presents best practices for catalogs and metadata appicable to collections and granules.
The following chapters present Best Practices for one particular topic:
1.3 Terms, definitions and abbreviated terms#
1.3.1 Terms and Definitions#
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Satellite data that have been processed to a minimum set of requirements and organized into a form that allows immediate analysis with a minimum of additional user effort and interoperability both through time and with other datasets. |
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A granule is the finest granularity of data that can be independently managed. A granule usually matches the individual file of EO satellite data. |
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A collection is an aggregation of granules sharing the same product specification. A collection typically corresponds to the series of products derived from data acquired by a sensor on board a satellite and having the same mode of operation. [RD01] |
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Named set of operations that characterize the behavior of an entity. |
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Information about a resource [RD02]. |
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Discrete unit of metadata [RD02]. |
1.3.2 Acronyms#
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Application Programming Interface |
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Analysis Ready Data |
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Committee on Earth Observation Satellites |
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Common Query Language |
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Directory Interchange Format Version 10 |
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Earth Observation |
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Global Change Master Directory |
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Hypertext As The Engine Of Application State |
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International Directory Network |
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JavaScript Object Notation |
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Open Geospatial Consortium |
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OpenSearch Description Document |
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Simple Storage Service |
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Spatiotemporal Asset Catalog |
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Working Group on Information Systems and Services |