Sky Surveillance: Gaze from Above
In the Winter 2024 edition of RYA magazine, a fascinating article was shared, delving into the world of Electronic Chart Systems (ECS) and maritime communications, and the critical role that Global Navigation Satellite Systems (GNSS) play in these domains.
GNSS systems, such as GPS, Galileo, GLONASS, and BeiDou, provide precise and reliable positioning, navigation, and timing information essential for safe and efficient maritime operations. This data is instrumental in enhancing the Safety of Life at Sea (SOLAS) and supporting navigation across all maritime phases, from ocean voyages to port maneuvers, under all weather conditions.
The article sheds light on how GNSS enables real-time vessel positioning on electronic charts, facilitating accurate route planning, collision avoidance, and navigation in constrained or busy waterways. For maritime communications, GNSS ensures the synchronized timing necessary for communication protocols and helps in tracking and monitoring vessels globally, which is vital for traffic management and maritime domain awareness.
The article also discusses the three primary satellite categories that contribute to GNSS: Geostationary Earth Orbit (GEO), Medium Earth Orbit (MEO), and Low Earth Orbit (LEO).
GEO satellites, orbiting approximately 35,786 km above the equator, provide continuous coverage to specific regions. They contribute to augmentation systems like EGNOS, enhancing GNSS accuracy and integrity over maritime areas.
MEO satellites, orbiting at about 20,000 km, form the core GNSS constellations and provide the fundamental positioning, navigation, and timing signals essential for ECS and maritime communications worldwide.
LEO satellites, orbiting much closer, between 500 and 2,000 km altitude, are increasingly deployed in complementary navigation, communication, and tracking roles. Their lower altitude enhances signal strength and latency, useful for resilient navigation solutions in GPS/GNSS-compromised environments and improving the robustness of maritime navigation and tracking systems.
Recently, the COSPAS SARSAT system, which delivers distress messages from Emergency Position Indicating Radio Beacons (EPIRBs) and Personal Locator Beacons (PLBs), has started using more MEO satellites. Once fully functional, this system will provide complete global coverage and almost real-time beacon detection, filling the permanent blind spot in the polar regions that GEO satellites have.
In conclusion, the integration of GNSS data supports a wide range of modern maritime technologies, from automated identification systems (AIS) and long-range tracking to autonomous vessels and search and rescue operations. The evolution of GNSS systems promises to further enhance the safety, efficiency, and resilience of maritime operations in the digital age.
[1] Maritime Navigation and Communication Systems
[2] The Importance of GNSS in Maritime Operations
[3] The Role of GNSS in Maritime Navigation and Communication
[4] The Future of GNSS in Maritime Navigation and Communication
[1] The integration of Global Navigation Satellite Systems (GNSS) data plays a crucial role in maritime navigation and communication systems, supporting advanced technologies such as Automated Identification Systems (AIS), long-range tracking, and autonomous vessels.
[2] In the realm of maritime operations, technology like data-and-cloud-computing and technology provide invaluable tools for enhancing Safety of Life at Sea (SOLAS) by enabling real-time vessel positioning, accurate route planning, and collision avoidance, among other functionality.
