Implementing NOAA’s S-100 based product suite —
Developer Information
S-100, the Universal Hydrographic Data Model, is a hydrographic geospatial data standard that can support a wide variety of hydrographic-related digital data sources, and aligns with mainstream international geospatial standards, in particular the ISO 19000 series of geographic standards. This alignment enables easier integration of hydrographic data and applications into geospatial solutions. S-100 is inherently more flexible than the existing S-57 and makes provision for the use of imagery and gridded data types, enhanced metadata and multiple encoding formats. It also provides a more flexible and dynamic maintenance regime for features, attributes and portrayal via a dedicated online registry. S-100 provides a framework of components to enable the building of standardized product specifications for hydrographic data modelling, thus providing true interoperability between different data standards and systems.
Because different product specifications are tied to different editions of S-100, the latest valid editions are displayed on the IHO website within the IHO Geospatial Information Registry. This is the same location as officially published IHO product specifications.
S-100 is a multi-part model based framework that uses the Unified Modeling Language (UML) to describe the different elements used in different product specifications. S-100 also maintains a set of schemas that describes how specific parts of S-100 are put together, such as the feature catalogues and the discovery metadata. Currently, the baselined UML models and schemas for edition 4.0.0 of S-100 are stored on GitHub. The IHO maintains links to the relevant repositories here.
S-100 maintains a set of common data encodings to minimize the need for system developers to implement different types of data. Currently, S-100 maintains the following encodings:
Encoding Product | Specification |
ISO 8211 Binary | S-101, S-401 |
HDFS | S-102, S-104, S-111 |
GML (profile of ISO 19136) | S-122, S-412, S-421 |
It is important to realize that each of these encodings are a profile and have been adapted to fit the S-100 framework. For example, the ISO 8211 profile in S-100 is different from the one contained within S-57, whereas S-100 includes new types of features and attributes, such as complex and information types.
The full encodings for S-100 are found in part 10 of S-100.
Every product specification must have a feature catalogue. The feature catalogue contains definitions and descriptions of the feature types, feature attributes, and feature associations occurring in one or more sets of geographic data. The feature catalogue acts as a machine-readable representation of the application schema, and gives a system the means to describe the elements of a dataset that conform to the feature catalogue.
Feature catalogues are created for each product specification and are found in the IHO Geospatial Information Product.
Portrayal is an optional component of a product specification. However, if consistent portrayal across all user platforms is important to an S-100 based data product, specifying how portrayal is done becomes mandatory. Within S-100 pProduct specifications, this is achieved by including a portrayal catalogue. The portrayal catalogue is a collection of defined portrayal instructions for a feature catalogue, and includes portrayal functions, symbols, and portrayal context.
Two types of portrayal catalogues are possible in S-100; XSLT and LUA. Part 9 of S-100 provides instructions for how a product specification can include an input schema derived from the abstract schema provided, a set of mapping rules (defined in XSLT or LUA), a set of symbols (defined in SVG format), line styles, colors, etc. and makes it available for use with product datasets.
In order for systems to leverage S-100 portrayal they must implement both XSLT and LUA mechanisms. LUA is generally used for product specifications that need to implement complex rules that interface with outside parameters. XSLT is used for simple portrayal rule generation.
If a product specification has defined a portrayal catalogue, it is found in the IHO GI product specification register.
For information exchange, there are several categories of metadata required—metadata about the overall exchange catalogue, metadata about each dataset contained in the catalogue, and metadata about the support files that make up the package. These are called discovery metadata in S-100 and they are used within the exchange set to enable users to learn about the content without having to open each dataset or support file.
Discovery metadata for datasets
S-100 specifies that discovery metadata for datasets is contained within an external XML file created in accordance with the S-100 metadata schema. This metadata set complies with the minimum metadata and extends it to provide more details, for example about reference datums and data issue dates. More information about discovery metadata for datasets can be found in the normative Appendix 4a-D Discovery Metadata for Information Exchange Catalogues of S-100.
Discovery metadata for support files
S-100 specifies that discovery metadata for support files is contained within an external XML file created in accordance with the S-100 metadata schema. This metadata set complies with the minimum metadata and extends it to provide information about managing the support files in order to update these. More details can be found in the normative Appendix 4a-D Discovery Metadata for Information Exchange Catalogues of S-100.
Discovery metadata allows for machine to machine data discovery. This will allow system developers to script against the discovery metadata to query if new data has been made available and then download the data directly to the system.
Encryption and authentication are described in Part 15 of S-100. Part 15 defines the standardized methods and algorithms for the encryption of file based components of datasets as well as feature and portrayal catalogues. Algorithms and methods for the production of digital signatures are defined, as well as the surrounding infrastructure required for key management and identity assurance within the IHO data protection scheme.
As part of its S-100 dissemination system, NOAA intends to leverage the IHO’s digital signature scheme to authenticate its products and will continue to provide its products unencrypted. It should be noted that users who receive NOAA data through authorized value added resellers will receive encrypted data using the IHO’s encryption scheme.
NOAA’s Precision Marine Navigation Data Dissemination System is providing a service to disseminate NOS Operational Forecast System (OFS) surface currents leveraging the IHO’s S-100 framework. The IHO has developed the S-111 Surface Current product specification that provides the methodology to store and send water current data and metadata. This standard has been designed for interoperability with electronic navigational charts and other IHO S-100 product specifications. S-111 aims to standardize surface currents for use in navigation systems in order to improve navigation decision support for mariners.
The S-100/S-111 compliant HDF5 datasets produced by NOAA have been converted to a regular grid and subsetted to provide an easily digestible size and format that can be used by electronic chart display and information systems (ECDIS), portable pilot units (PPU), and electronic charting systems (ECS).
The following tables outline the basic information for a subset of the OFS models that have been prototyped for operations. A full list of the available models is provided at the end of this document.
The official IHO product specification and associated files can be found here.
NOAA has developed a set of open source python scripts to convert native netCDF data into S-111 edition 1.0.0 datasets. The scripts are available here.
Chesapeake Bay Operational Forecast System (CBOFS)
IHO Specifications | S-100
Edition 4.0.0 S-111 Edition 1.0.0 |
Discovery Metadata | https://noaa-s111-pds.s3.amazonaws.com/index.html#ed1.0.1/model_forecast_guidance/cbofs/ |
Format | HDF5 |
Model | ROMS |
Observation Parameter | Surface currents |
Coordinate System | WGS 84 |
Time Zone | UTC |
Frequency | 4 times daily cycle (0, 6, 12, 18 UTC) |
Forecast | 48 hours |
Spatial Resolution | ~500 m |
Depth | -4.5 m |
Data Coverage | Chesapeake Bay VA and MD |
HDF5 Files | 63 |
Global Real-Time Operational Forecast System (RTOFS)
IHO Specifications | S-100
Edition 4.0.0 S-111 Edition 1.0.0 |
Discovery Metadata |
https://noaa-s111-pds.s3.amazonaws.com/index.html#ed1.0.1/model_forecast_guidance/rtofs_east/
https://noaa-s111-pds.s3.amazonaws.com/index.html#ed1.0.1/model_forecast_guidance/rtofs_west/ |
Format | HDF5 |
Model | HYCOM |
Observation Parameter | Surface currents |
Coordinate System | WGS 84 |
Time Zone | UTC |
Frequency | Daily cycle (0 UTC) |
Forecast | 72 hours / 6-hour interval |
Spatial Resolution | ~8500 m |
Depth | -4.5 m |
Data Coverage | US East and US West |
HDF5 Files | US East: 39, US West: 28 |
The full list of OFS models available include:
- Chesapeake Bay Operational Forecast System (CBOFS)
- Delaware Bay Operational Forecast System (DBOFS)
- Gulf of Maine Operational Forecast System (GOMOFS)
- Lake Erie Operational Forecast System (LEOFS)
- Lake Michigan and Huron Operational Forecast System (LMHOFS)
- Lake Ontario Operational Forecast System (LOOFS)
- Lake Superior Operational Forecast System (LSOFS)
- Northern Gulf of Mexico Operational Forecast System (NGOFS)
- New York/New Jersey Harbor Operational Forecast System (NYOFS)
- San Francisco Bay Operational Forecast System (SFBOFS)
- Tampa Bay Operational Forecast System (TBOFS)
- Global Real-Time Ocean Forecast System (RTOFS East)
- Global Real-Time Ocean Forecast System (RTOFS West)
- West Coast Operational Forecast System (WCOFS)
NOAA's Precision Navigation dissemination system is providing a service to disseminate NOS high resolution bathymetry leveraging the IHO's S-100 framework. The S-102 Bathymetric Surface data product consists of a set of values organized to form quadrilateral grid coverage with associated metadata representing a bathymetric depth model for an area of the sea, river, lake, or other navigable waterway. The dataset includes both depth estimate values and uncertainty estimates associated with the depth values. The addition of a discrete point set called a “tracking list” allows a hydrographer to override any particular grid matrix value to deliberately bias the data for safety of navigation. That is, the dataset can carry both measured depth information that may be used for scientific purposes as well as corrected depth information that may be used for navigation. S-102 aims to standardize gridded bathymetry products for use in navigation systems in order to improve navigation decision support for mariners.
The official IHO product specification and associated files can be found in the S-102 product specification.
NOAA has developed a set of open source python scripts to convert native bathymetric attributed grid (BAG) data into S-102 edition 2.1.0 datasets. The scripts are available here.
IHO Specifications | S-100
Edition 4.0.0 S-102 Edition 2.1.0 |
Discovery Metadata | https://noaa-s102-pds.s3.amazonaws.com/index.html |
Format | HDF5 |
Coordinate System | WGS 84 |
Related Links
Explore the prototype data for S-102 High Resolution Bathymetry.
Explore the prototype data for S-111 surface currents and supporting documentation.
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