Harmonic Constants XML Scheme


This XML scheme provides a standard transfer mechanism for tidal harmonic constants, which has been adopted by Member States of the International Hydrographic Organization (IHO), and can be downloaded directly from the links below.

The XSD schema file and example XML files are freely available for download. The schema file can be used to validate XML files using a tool such as Altova XMLSpy (www.altova.com) or any other tools which supports XML validation.

The example XML files are designed to demonstrate the difference between XML which is compliant with the schema and XML which is not. Furthermore, the Example1 XML files demonstrate that the speed component of each harmonic can be included if required, whereas the Example2 XML files show data without the speed component. Note that the examples without speed information are still valid according to the schema. The preferred way of naming each XML file would be to use the Port Name.

Schema Downloads


Sample Downloads​​ ​

Example 1 - Bad ​​​​

Example 1 - Good ​​

Example 2 - Bad ​​​​

Example 2 - Good

More information about general XML can be found at www.w3schools.com

Tidal Harmonic Constants product specification


The Harmonic Constants product specification gives full details of the structure and content of the exchanged file(s), and can be viewed/downloaded below.

Specification downloads

HC Exchange Format product specification 

HC Exchange Format Annex A 

HC Exchange Format Annex B