Core Value of High-Precision Inertial Navigation in Modern UUV Operations
Modern Unmanned Underwater Vehicles (UUVs) have been widely applied in key scenarios such as deep-sea resource exploration, underwater security patrols, marine ecological monitoring, and shipwreck salvage. Their operational environments range from coastal shoals to 10,000-meter deep seas, facing three severe challenges: signal shielding, high pressure and low temperature, and water current disturbance. Traditional navigation solutions are prone to positioning drift and attitude inaccuracy, failing to meet UUVs’ core requirements for long-range autonomous operations, precise trajectory control, and data traceability. High-precision GNSS/INS integrated technology has become the key to solving this dilemma, endowing UUVs with an “underwater precise navigation brain.”
Why UUV Operations Must Rely on Advanced GNSS/INS Integrated Solutions
During underwater operations, UUVs are completely out of GNSS signal coverage and need to address issues such as attitude fluctuations caused by water current impacts, sensor interference from equipment vibrations, and hardware erosion due to deep-sea low temperature and high pressure. Single inertial navigation tends to accumulate errors over time, while pure acoustic navigation is greatly affected by environmental noise. Only the integrated solution combining GNSS calibration and inertial navigation can achieve the navigation effect of “fast calibration when surfacing and continuous precision underwater,” avoiding operational deviations, mission failures, or even UUV loss of contact.
Core Advantages of the AsteRx-i3 D Pro+ GNSS/INS Board
Designed as a professional-grade GNSS/INS solution for harsh closed environments, the AsteRx-i3 D Pro+ focuses on “continuous reliability and compact adaptability,” perfectly matching the special needs of UUV operations with prominent core advantages:
Multi-Constellation, High-Channel Signal Reception Capability
Equipped with 544 hardware channels, it supports simultaneous tracking of full-constellation GNSS signals (GPS, GLONASS, BeiDou, Galileo, QZSS, SBAS). During the UUV surfacing positioning phase, even in complex offshore electromagnetic environments or under wind and wave interference, it can quickly capture stable signals to complete position calibration and data updates.
Underwater-Adapted GNSS+ Technology Suite
Relying on Septentrio’s patented GNSS+ technology suite, it provides full-process guarantee for UUV navigation:
AIM+ Advanced Anti-Interference and Anti-Spoofing Technology: Resists offshore electromagnetic interference and external signal spoofing, ensuring pure signals during the surfacing positioning phase;
APME+ Multipath Suppression Technology: Eliminates signal errors caused by sea surface reflections and wave interference, improving surfacing positioning accuracy;
LOCK+ Stable Tracking Technology: Maintains uninterrupted signal tracking during the bumpy process of UUV surfacing and submerging;
FUSE+ Sensor Fusion Technology: Deeply integrates GNSS positioning and IMU data, providing long-time high-precision dead reckoning for the underwater phase.
High-Precision Attitude Perception: Precise Control of Underwater Trajectory
It features centimeter-level RTK-INS positioning accuracy (horizontal: 0.6 cm + 0.5 ppm; vertical: 1 cm + 1 ppm). In dual-antenna RTK mode, the heading accuracy reaches 0.15°, and the pitch/roll accuracy is 0.02°. A single antenna can also output complete attitude data, perfectly adapting to the compact layout of UUVs. With a speed accuracy of 0.02 m/s in RTK mode, it can accurately capture trajectory deviations caused by water currents, ensuring the operational path does not deviate from the preset route. 
In-Depth Integration Application with UUV Systems
The AsteRx-i3 D Pro+ can be integrated into UUV navigation systems without complex modifications, transforming technical advantages into actual operational efficiency:
Long-Range Autonomous Navigation Guarantee
FUSE+ sensor fusion technology supports long-time underwater dead reckoning, significantly reducing the frequency of UUV surfacing calibration, extending the duration of a single underwater operation, meeting the needs of scenarios such as deep-sea long-distance exploration and large-scale security patrols, and improving operational efficiency.
Extreme Environment Resistance Design
Adopting military-grade rugged standards, it has an operating temperature range of -40°C to +85°C, capable of withstanding temperature fluctuations caused by deep-sea low temperatures and equipment heat dissipation; complying with the MIL-STD-810G vibration standard, it resists vibrations from UUV propulsion systems and water current impacts; with 5% – 95% (non-condensing) humidity adaptability and RoHS environmental certification, it is suitable for long-term stable operation in closed underwater cabins.
Lightweight and Low-Power Consumption Adaptability
The board weighs only 30 grams and has a volume of 47.5×70×10.5 mm, which can be flexibly installed in the limited cabin space of small UUVs; its ultra-low power consumption of 1.0W-1.2W will not additionally increase the energy burden of UUVs, ensuring operational endurance and avoiding mission interruptions due to insufficient power.
Multi-Device Collaboration Compatibility
Supporting standard data formats such as SBF, NMEA 0183, and RTCM, it can seamlessly collaborate with UUV equipment such as sonar detection, underwater cameras, and robotic arms, synchronously outputting raw GNSS/IMU data to provide complete support for multi-sensor fusion analysis and operational data traceability; the intuitive Web interface and SDK tools simplify system integration and parameter debugging processes.
AsteRx-i3 D Pro+: A Reliable Core for UUV Deep-Sea Operations
The board endows UUVs with dual guarantees of “precise navigation + stable operation,” becoming an indispensable core equipment for deep-sea operations:
Enhance the Value of Operational Results
High-precision positioning and attitude data ensure the accuracy of underwater survey maps, resource exploration coordinates, and cultural relic location markers, providing highly credible data support for scientific research analysis and engineering construction, and avoiding the invalidation of results due to navigation errors.
Adapt to Diverse UUV Application Scenarios
From civil marine environmental monitoring and fishery resource exploration to professional underwater pipeline inspection and shipwreck salvage, as well as deep-sea ecological research in the scientific field, it can adapt to various UUV platforms and meet the navigation needs of different operational scenarios.
Support UUV Technology Upgrading and Iteration
Full-constellation compatibility and advanced sensor fusion technology can meet the future intelligent upgrading needs of UUVs, providing a stable navigation foundation for equipping new equipment such as lidar and multi-beam sonar, and helping UUVs develop towards longer ranges and higher autonomous levels.
Summary:
Modern Unmanned Underwater Vehicles (UUVs) operate in extreme underwater environments with no GNSS coverage, strong currents, high pressure, low temperatures, and sensor disturbances. Traditional navigation methods—pure INS or acoustic solutions—cannot maintain long-duration accuracy, causing drift, mission deviation, or loss of the vehicle. High-precision GNSS/INS integrated technology is essential because it enables fast GNSS calibration when surfacing and continuous high-precision dead reckoning underwater.
The AsteRx-i3 D Pro+ GNSS/INS board is built for harsh, enclosed underwater environments, offering continuous reliability and compact adaptability. Its 544-channel multi-constellation receiver ensures fast and stable GNSS capture during surfacing, even in noisy offshore electromagnetic conditions. The GNSS+ technology suite (AIM+, APME+, LOCK+, FUSE+) strengthens anti-interference, multipath suppression, stable tracking, and long-duration underwater inertial navigation.
It delivers centimeter-level RTK-INS positioning, highly accurate attitude sensing (0.15° heading; 0.02° pitch/roll), and 0.02 m/s speed accuracy—crucial for maintaining precise underwater trajectories and resisting current-induced drift. Its compact size (30 g), ultra-low power consumption (1.0–1.2 W), and rugged MIL-STD-810G design make it ideal for small and deep-sea UUVs, withstanding extreme temperatures, vibration, and humidity.
The board integrates easily with UUV systems, supports long-duration underwater missions through stable dead reckoning, and is compatible with sonar, cameras, robotic arms, and multi-sensor fusion via standard formats like SBF, NMEA, and RTCM.
Ultimately, the AsteRx-i3 D Pro+ provides UUVs with a precise navigation core, improving underwater data accuracy, operational reliability, and mission success. It supports diverse applications—from environmental monitoring to deep-sea exploration and salvage—and is future-ready for advanced autonomous UUV development.
