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GNSS/INS Manufacturers & Suppliers
Hexagon | NovAtel
Precise GNSS & GPS Positioning Solutions for the Toughest Marine & Maritime Environments
Platinum Partner
SBG Systems
Advanced Inertial Navigation, Motion & Positioning Solutions for Marine Applications
Platinum Partner
Advanced Navigation
High-Accuracy Inertial Sensors & Acoustic Positioning Systems for Marine, Maritime & Offshore Applications
Platinum Partner
Xsens
High-Performance Compact Inertial Sensing Modules for Marine & Subsea Applications
Gold Partner
Products: Marine GNSS/INS
The Complete Guide to GNSS/INS for Marine & Maritime Navigation Systems
Introduction to GNSS/INS
GNSS/INS – also known as GPS/INS technologies provide precise positioning and navigation for marine and maritime vessels, enhancing safety, efficiency, and autonomy across diverse operational environments. Integrated Global Navigation Satellite System (GNSS) and Inertial Navigation System (INS) solutions are increasingly critical to operations where accurate geospatial awareness is essential, even in GNSS-denied environments such as underwater or near complex coastal infrastructure.
These systems combine the global precision of satellite navigation with the local accuracy of inertial sensors. This fusion ensures reliable real-time data on position, orientation, and velocity for crewed and uncrewed platforms operating on or below the ocean surface. These systems support everything from seabed mapping to autonomous docking and are vital for enabling intelligent marine operations in both commercial and defense settings.
Subsea & Marine GNSS/INS Applications
Boreas D90 digital FOG GNSS-INS by Advanced Navigation
GNSS/INS systems are used in many marine applications, providing high-precision navigation and orientation data for vessels and platforms operating in complex or dynamic settings. Typical use cases include:
Hydrographic and Bathymetric Surveys
Survey-grade GNSS/INS systems are used in multibeam and single-beam echo sounder operations, providing accurate georeferenced depth data for seabed characterization, dredging, and infrastructure planning.
GNSS/INS for Remotely Operated Vehicles (ROVs)
ROVs conducting cable inspection, maintenance, or salvage rely on tightly coupled GNSS/INS data relayed from surface vessels to maintain position and execute controlled movements.
GNSS/INS for Autonomous Underwater Vehicles (AUVs)
AUVs use embedded inertial systems and occasional GNSS fixes at the surface or via acoustic modems to navigate complex missions in GNSS-denied underwater environments.
GNSS/INS for Uncrewed Surface Vessels (USVs)
Enables autonomous waypoint navigation, station keeping, and dynamic avoidance for USVs used in survey, security, and environmental monitoring.
Ship Navigation and Collision Avoidance
Large ships use integrated navigation systems for safe routing, docking, and collision avoidance in congested or low-visibility conditions.
Dredging and Port Operations
Accurate INS-corrected positioning enhances dredge head tracking, sediment management, and alignment of port infrastructure.
Offshore Asset Monitoring
Aids in the stabilization and tracking of floating platforms, cranes, and sensor arrays used in offshore oil and gas, wind, and marine energy installations.
Many operations use GNSS/INS in combination with Automatic Identification Systems (AIS), vessel traffic services (VTS), and sonar for comprehensive maritime domain awareness.
Types & Architectures of GNSS/INS Systems
Enables autonomous waypoint navigation, station keeping, and dynamic avoidance for USVs used in survey, security, and environmental monitoring.
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Compact high-performance GNSS/INS by SBG Systems.
Tactical-Grade IMU-Based INS: Systems built around tactical-grade MEMS or compact FOG sensors. These balance accuracy with low power and small form factor, making them common in USVs, small AUVs, and portable survey equipment.
- Survey-Grade INS: Incorporates high-performance FOG or ring laser gyros, enabling centimeter-level accuracy when combined with RTK correction data. Widely used in hydrographic surveys, ROV operations, and precision georeferencing tasks.
- High-Precision Embedded Units: Compact GNSS/INS modules integrated into control electronics or payloads, optimized for ROVs, AUVs, UAVs, and sensor pods where space is at a premium.
- EGI Systems (Embedded GPS/INS): Typically deployed in defense, maritime, and aerospace systems, combining robust IMUs with secure, anti-jamming GNSS for mission-critical navigation and targeting.
- Marine Strapdown Systems: Solid-state designs with no moving parts, offering robustness in high-dynamic environments and resistance to mechanical shock and vibration.
- AHRS Modules: Attitude and Heading Reference Systems provide real-time orientation data and are often integrated with GNSS/INS in marine platforms to support vessel stabilization, auto-heading, and control.
Coupling architectures define how data integration is managed:
- Loosely Coupled: GNSS and INS data are processed independently and fused at a higher level. Simpler but less resilient in challenging environments.
- Tightly Coupled: Raw GNSS signal data and INS outputs are combined directly, allowing navigation even with fewer than four satellite signals.
- Deep or Ultra-Tightly Coupled: Integrates GNSS signal tracking loops with inertial data, enhancing resilience against jamming and spoofing.
Performance Factors & Metrics
System performance is evaluated across several key dimensions:
- Position Accuracy: High-end systems achieve sub-meter to centimeter-level accuracy using RTK or PPP corrections. Accuracy may degrade with GNSS dropout, but is stabilized by INS.
- Attitude Accuracy: Roll, pitch, and yaw measurements are critical for platform orientation, particularly during dynamic movement.
- Heading Resolution: Especially important for docking, underwater cable laying, and navigation near obstacles.
- Latency and Update Rate: High-frequency data output is required for real-time control loops in autonomous systems.
- Robustness: Systems are evaluated for shock, vibration, temperature, and electromagnetic compatibility (EMC), particularly in naval deployments.
High-end systems may also include anti-spoofing, interference mitigation, and redundancy through multiple GNSS constellations or auxiliary sensors.
Regulatory & Industry Standards
GNSS/INS solutions used in maritime environments often conform to international and defense standards. These include:
- IMO Performance Standards: For shipborne GNSS equipment in commercial vessels.
- NMEA 0183 / NMEA 2000: Communication protocols for marine electronics.
- MIL-STD-810 & MIL-STD-461: Environmental and electromagnetic standards for naval and defense platforms.
- STANAG 4576: Defines INS parameters and formats for NATO forces.
- RTCM SC-104 & NTRIP Protocols: Used for real-time GNSS correction data transmission.
Adherence ensures system interoperability, mission assurance, and safety of navigation in international waters.
Integration With Marine Systems
Modern GNSS/INS systems are increasingly integrated with other vessel subsystems for real-time data exchange, control, and monitoring. Examples include:
- Sensor Fusion With Sonar and DVL: For improved underwater navigation and seabed mapping.
- Linkage to Autopilots and Thrusters: Enabling dynamic positioning and precise maneuvering during docking or equipment deployment.
- Mission Management Systems: Real-time GNSS/INS data feeds autonomous mission planners and navigation computers.
- Fleet Management Platforms: Use GNSS/INS data for centralized monitoring, route optimization, and operational coordination across vessel groups.
- Situational Awareness Dashboards: Provide navigation crews or remote operators with fused geospatial data, alerts, and diagnostics.
Interoperability is enhanced by standardized data buses (e.g., CAN, Ethernet), software APIs, and modular hardware architectures.
Future Developments & Trends
As maritime operations become more autonomous and data-driven, GNSS/INS technologies are evolving to meet higher expectations for accuracy, resilience, and integration:
- Machine Learning for Sensor Fusion: AI-based fusion techniques are being developed to improve robustness in degraded or denied conditions.
- Compact High-Accuracy IMUs: Enabling tighter SWaP-C performance for small uncrewed platforms.
- Multi-Sensor Redundancy: Combining multiple GNSS receivers, IMUs, and aiding sensors to provide failover capabilities in critical missions.
- GNSS-Denied Navigation Research: Exploring hybrid approaches using magnetometers, vision-based localization, and inertial sensing.
- Cybersecurity and Hardening: Enhancing protection against jamming, spoofing, and cyber intrusion, particularly in defense and dual-use systems.
Continued advancement in GNSS/INS is essential for expanding maritime autonomy, safety, and situational awareness across global ocean domains.
