Overview
IEC 61108-7:2024 establishes the minimum performance standards, testing methods, and required test outcomes for shipborne receivers operating with Satellite Based Augmentation System (SBAS) L1 signals to enhance GPS navigation. Developed by the International Electrotechnical Commission (IEC), this standard addresses the integration of SBAS L1 augmentation into maritime GPS receivers, ensuring improved positional accuracy and integrity as required under IMO Resolutions MSC.112(73) and A.1046(27).
SBAS augments GNSS signals by providing corrections and integrity information through geostationary satellites, thereby supporting navigation in ocean waters, coastal regions, harbor entrances, and approaches. By setting clear requirements for SBAS L1 receiver performance under SBAS service coverage, IEC 61108-7:2024 supports safe, reliable maritime navigation.
Key Topics
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Minimum Performance Standards
The standard specifies essential criteria for SBAS L1 receiver equipment, including signal reception, data processing, output provisions, and display capabilities. This includes robust requirements for receiving both GPS L1 and SBAS L1 signals, processing navigational data, and indicating SBAS usage in computed navigation solutions.
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Configuration and Operation
Receiver equipment must provide both automatic and manual modes for selecting augmentation services, prioritizing DGPS corrections when available, but allowing user selection of preferred augmentation method-vital for overlapping service regions.
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Testing and Quality Assurance
IEC 61108-7:2024 outlines comprehensive methods of testing, such as signal acquisition, position accuracy, positional update rates, sensitivity, and resistance to signal interference. Quality assurance processes aligned with recognized standards ensure equipment reliability.
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Compliance and Integrity
The standard mandates mechanisms for integrity monitoring, ensuring prompt warning and user alert within required timeframes if position errors exceed defined thresholds, as well as rigorous alert management procedures relevant to maritime operations.
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Terminology and Definitions
The document provides standardized definitions for key GNSS and SBAS concepts such as accuracy, availability, integrity, Horizontal Alert Limit (HAL), and others, supporting consistency across navigational systems and stakeholders.
Applications
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Shipborne Navigation
SBAS-augmented GPS receivers compliant with IEC 61108-7:2024 enhance navigational performance for ships traversing ocean waters, coastal zones, harbor entrances, and approach channels, supporting safe and efficient marine operations.
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Conformance with IMO Requirements
The standard provides a means for manufacturers and operators to meet the operational performance criteria established in IMO Resolutions A.1046(27) and MSC.112(73), facilitating regulatory approval and international interoperability.
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Integrated Navigation Systems (INS)
When implemented within Integrated Navigation Systems or multi-system PNT solutions, the required capabilities-such as position display, data control, and alerting-can reside within the broader system framework, optimizing bridge operations.
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Worldwide SBAS Coverage
The standard supports the use of multiple regional SBAS services (e.g., WAAS, EGNOS, MSAS, GAGAN) in maritime environments, ensuring consistent navigation performance for ships operating globally.
Related Standards
- IEC 61108-1: Maritime navigation and radiocommunication equipment and systems – GNSS – Part 1: Global Positioning System (GPS) – Receiver equipment – Performance standards, methods of testing and required test results
- IEC 61108-4: Shipborne DGPS and DGLONASS maritime radio beacon receiver equipment
- IEC 60945: General requirements, methods of testing and required test results for maritime navigation equipment
- IEC 61162 Series: Digital interfaces for navigation and radiocommunication equipment
- RTCA DO-229F: Minimum Operational Performance Standards for GPS/SBAS Airborne Equipment
- IMO Resolution A.1046(27): Performance standards for shipborne GNSS receiver equipment
Adopting IEC 61108-7:2024 ensures the reliability and precision of SBAS-enabled maritime GNSS receivers, facilitating compliance, interoperability, and enhanced safety across the global maritime industry.