ISO 22090-3:2014

Overview

ISO 22090-3:2014 - Ships and marine technology - Transmitting heading devices (THDs) - Part 3: GNSS principles specifies the requirements for transmitting heading devices that determine and provide a ship’s true heading using GNSS principles (measuring RF carrier phase of GNSS signals). The standard sets out general requirements for construction, performance, testing and interfaces as required by Chapter V of SOLAS 1974. It is intended for THDs that feed heading information into bridge systems and integrated navigation systems.

Key topics and requirements

• Scope and principle: THDs based on GNSS principles - heading derived from GNSS carrier-phase measurements of directional sources (GNSS antennas).
• Performance & functionality: Devices must output true heading, allow alignment to the ship’s fore-and-aft line, protect manual correction parameters, and support continuous operation under environmental stresses.
• Operational envelope: Minimum operating range from 70° S to 70° N latitude and capable of handling a maximum rate of turn of 20°/s.
• Availability & resilience:
  • Settling time: less than 10 minutes in static conditions with a usable satellite almanac.
  • Compensation for brief GNSS signal interruption: maintain heading accuracy for 60 s during signal loss.
  • Alerting: required alerts for device malfunction/power failure and GNSS interruption exceeding 60 s; alert interfaces must follow Bridge Alert Management (IMO Res. MSC.302(87)).
• Accuracy and errors: Defines and requires testing for static error (settle point error), dynamic error, and follow-up error; specifics are addressed through type tests and accuracy tests in the standard.
• Type tests and conformity: Includes settling-time tests, static/dynamic/follow-up error tests, back-up, environmental (vibration, humidity, temperature), EMC, interface and malfunction tests (see clauses 6.x).
• Interfaces & presentation: Compatibility with maritime digital interfaces (e.g., IEC 61162 series) and presentation requirements per IMO/IEC guidance; displays and outputs shall indicate true heading.

Applications and who uses it

• Shipbuilders, OEMs and manufacturers of GNSS-based heading sensors and THDs
• Bridge system integrators and suppliers of Integrated Navigation Systems (INS)
• Naval architects, marine electronics engineers, classification societies and flag administrations for type approval and compliance checks
• Ship operators and operators of high-speed craft requiring certified heading information for navigation and safety systems
• Test laboratories performing type approvals and EMC/environmental testing

Related standards

• ISO 22090-1 (Gyro-compasses), ISO 22090-2 (Geomagnetic principles) - other THD technology parts
• IEC 60945, IEC 61162-1/2, IEC 61924-2, IEC 62288
• IMO Resolutions: MSC.116(73), A.694(17), MSC.302(87), A.813(19), A.821(19)

Keywords: ISO 22090-3:2014, transmitting heading devices, THD, GNSS principles, SOLAS, marine navigation, heading accuracy, settling time, GNSS interruption, bridge alert management.