Standard S-100

General Description

The S-104 product, developed within the framework of the IHO S-100 standard, defines the data model and exchange format for representing the sea surface height relative to a reference datum, with the purpose of supporting safe navigation and the management of maritime operations affected by tidal conditions.

The Instituto Hidrográfico (IH) is developing this S-104 sub-product with the aim of achieving operational implementation and distribution to the maritime community, based on observed and forecast tidal data.

Organisation and Structure

The S-104 model follows a hierarchical structure designed to be compatible with other electronic navigation products (e.g. S-101 ENCs), ensuring interoperability with other marine information layers when used within Electronic Chart Display and Information Systems (ECDIS).

Each S-104 dataset contains not only the sea surface height data, but also metadata describing these values — including their origin, vertical reference system and temporal coverage.

As these products include tidal predictions with variable temporal resolutions (e.g. 15-minute or 1-hour intervals), they are particularly relevant for voyage planning and navigational safety.

Format and Access

The S-104 data, in accordance with the product specification, will be provided in digital HDF5 format and made available to users through S-100 data dissemination platforms, following the completion of the creation and validation process.