Zarr can represent very large array datasets in a simple, scalable way, and is compatible with cloud object storage – making it ideal for analysis-ready geospatial data. CoverageJSON has been demonstrated to be an effective, efficient format, friendly to web and application developers. Both are considered for OGC adoption.
An approved OGC Community Standard is an official standard of OGC that is considered to be a widely used, mature specification, but was developed outside of OGC’s standards development and approval process. The originator of the standard brings to OGC a “snapshot” of their work that is then endorsed by OGC membership so that it can become part of the OGC Standards Baseline.
Zarr and the OGC
The Open Geospatial Consortium (OGC) seeks public comment on the draft Zarr Storage Specification 2.0 Community Standard. While Zarr is not inherently a geospatial-specific format, it has been put forward by the Zarr Steering Council for adoption as an OGC community standard because of its rapid growth and adoption in geospatial and related fields. Zarr is an open-source specification for the storage of multi-dimensional arrays of data (also known as data cubes, N-dimensional arrays, ND-arrays, or tensors). Such arrays are ubiquitous in scientific research and engineering. Zarr stores metadata using .json text files and array data as (optionally) compressed binary chunks. Zarr can store data into most storage systems, including databases, standard ‘directory based’ file systems, and cloud object stores, such as Amazon S3. This flexibility allows implementations to experiment with novel storage technologies while maintaining a uniform API for downstream libraries and users. The candidate Zarr Storage Specification 2.0 Community Standard is available for review and comment on the OGC Portal. Comments are due by July 29, 2021, and should be submitted via the method outlined on the Zarr Storage Specification 2.0 Community Standard’s public comment request page.
CoverageJSON considered for OGC adoption
The Open Geospatial Consortium (OGC) is also considering CoverageJSON for adoption as an official OGC Community Standard. A new Work Item Justification to begin the Community Standard endorsement process is available for public comment. CoverageJSON is a simple, human- and machine-readable format for publishing spatio-temporal data to the Web. It is used for encoding coverage data such as multi-dimensional grids, time series, and vertical profiles, distinguished by the geometry of their spatio-temporal domain. CoverageJSON is based on the concepts and standards from ISO and OGC, and the specification is published openly on the web. The specification is supported by a Cookbook, plus a suite of open source tools for producing and consuming the format. Great interest in the format has already been shown by the user community, who are also encouraged to contribute to its development via GitHub. The candidate CoverageJSON Community Standard Work Item Justification is available for review and comment on the OGC Portal. Comments are due by July 25, 2021, and should be submitted via the method outlined on the CoverageJSON Community Standard Work Item Justification’s public comment request page.
More information on the Zarr Storage Specification 2.0 Community Standard
More information on CoverageJSON