Encoding Hydrodynamic Model Guidance from NOAA's Operational Forecast Systems in S-111 and S-104 International Standards to Support Precision Navigation

Over the past decade, the International Hydrographic Organization (IHO) has developed the S-100 Universal Hydrographic Data Model–-a “standard for standards” for maritime data. S-100 serves as the umbrella structure by which all other marine data product standards should follow, such as the new Electronic Navigational Chart (S-101), high-resolution bathymetry (S-102), water levels (S-104), surface water currents (S-111), and marine weather (S-41X). As the amount of maritime data increases and the diversity of data providers, types, and users continues to grow, these standards are critical for producing data in uniform, usable formats so that 1) navigation systems can easily integrate and seamlessly display the data, and 2) mariners can make effective, accurate, safe, and timely navigation decisions.

Recently, NOAA has been involved with S-100 in two ways: a) developing the data standards themselves (e.g. S-100, S-104, S-111, and S-41X), and b) producing S-100 compliant data which will be available for free from NOAA’s Precision Navigation Dissemination System. This presentation will primarily discuss NOAA’s role as a provider of S-111 (and soon S-104) Operational Forecast System (OFS) forecast guidance.

NOAA’s National Ocean Service (NOS) operates the OFS suite, which consists of 4-D hydrodynamic modeling systems generating gridded short-term nowcasts and 48 to 120 hour forecasts of water currents, water levels, water temperatures, and salinity in critical ports, harbors, estuaries, Great Lakes and coastal waters of the U.S. The OFS run four times daily on NOAA's Weather and Climate Operational Supercomputer System (WCOSS), providing critical operational predictions that support marine navigation, search and rescue, ecological forecasting, and scientific research.

In an effort to increase the practical usability of OFS in marine navigation systems and promote adoption of the S-100 international standards, the NOAA’s Office of Coast Survey (OCS) has begun to extract OFS guidance from its native NetCDF output files, encode surface currents into the S-111 format (and soon water levels into the S-104 format), and disseminate the output operationally. OCS is also producing S-111 files of predictions from NOAA’s Global Real-Time Ocean Forecast System (RTOFS) to support longer-range voyage planning. To accomplish these tasks, OCS has developed a modular Python toolkit to automate the conversion and dissemination process while allowing for its future extension to support additional oceanographic forecast modeling systems. OCS released this codebase under an open source license on GitHub to foster potential use by and collaboration with other hydrographic offices around the world. Ongoing work includes developing interoperability standards and testing products to ensure they meet mariner needs.