Hierarchical Data Format Version 5 (HDF5) is a data model, a programming interface, and a storage model for keeping and managing data. HDF5 supports an unlimited variety of data types, and is designed to be flexible and efficient for large and complex data. Due to its use of customizable data types, HDF5 is extensible, allowing communities and their applications to evolve the use and functionality of HDF5.
HDF5 provides an encoding standard particularly suitable to scientific and engineering geospatial applications that employ complex multidimensional datasets to describe phenomena that change over time and/or space.
HDF5 is designed to be simple yet versatile. HDF5 is capable of supporting complex data relationships and dependencies through its grouping and linking mechanisms. Additionally, HDF5 is self-describing through its accommodation of user-defined metadata.
The candidate OGC HDF5 Core standard defines the HDF5 data model to allow implementers to develop HDF5 content and tools using the HDF5 or other storage models and programming interfaces.
HDF5 is already in use by the OGC community: OGC’s NetCDF Enhanced Data Model can be fully described by the HDF5 data model because its storage format is also HDF5. However, the HDF5 data model includes several entities whose features go significantly beyond those of the NetCDF Enhanced model.
Furthermore, OGC members are using HDF5 as a standard format for more complex data types. In particular, HDF5 has been proposed as at least two standards for point cloud data in the OGC Point Cloud Domain Working Group, and has been demonstrated as a GDAL compliant format for images (KEA). HDF5 is also used as an open standard for other geographic data, such as the Bathymetric Attributed Grid (BAG) format, which is the basis for the International Hydrographic Organization’s standards.
The HDF5 data format and library was created and is maintained, by the HDF Group. The group’s mission is to ensure long-term access to data stored in HDF5 and support its dedicated and diverse user community. The organization actively partners with users to understand their needs and challenges and to help them use HDF5 effectively. As a long-time OGC member, The HDF Group actively contributes to numerous standards activities. The HDF Group chairs the OGC HDF Standards Working Group, where the conceptual model was developed.