High-Precision Positioning and Attitude Measurement Empowers Modern Marine Surveying

In contemporary marine surveying and hydrographic investigations, the precise position and three-dimensional attitude data of measurement platforms (such as survey vessels, unmanned surface vessels (USVs), and buoys) have become the foundation for acquiring reliable marine spatial information. Whether for nearshore engineering surveys, seabed topographic mapping, or marine resource exploration, traditional GNSS positioning systems struggle to meet the demands for high-precision and continuous measurements when facing complex sea conditions, signal obstructions, or dynamic platform motions.

Why Centimeter-Level GNSS/INS Positioning and 3D Attitude are Crucial for Marine Surveying

In the dynamic marine environment, ship motions induced by waves—roll, pitch, and yaw—directly affect the accuracy of data from sensors like echo sounders and side-scan sonars. Centimeter-level position deviations or attitude errors of a few tenths of a degree can lead to distortions in seabed topography, misalignment of feature points, and impact the accuracy of channel safety assessments and engineering designs. The AsteRx SBi3 Pro provides not only precise GNSS position but, more importantly, real-time 3D attitude (heading, pitch, roll) and robust dead reckoning capability during short-term GNSS signal outages (e.g., under bridges, near coastal structures), ensuring the spatiotemporal consistency and reliability of measurement data.

Core Advantages of the AsteRx SBi3 Pro GNSS/INS Receiver

The AsteRx SBi3 Pro is more than just a GNSS receiver; it is a ruggedized positioning and attitude determination system integrated with a high-performance Inertial Measurement Unit (IMU), designed specifically for demanding marine environments. Its core philosophy is: Always Reliable, Dynamically Precise, Ruggedly Durable.

Powerful Multi-System, Multi-Frequency GNSS Signal Tracking Capability

Designed for global operation with exceptional signal reception performance:

-544 hardware channels ensure simultaneous tracking of all visible satellite signals, enhancing availability and reliability.

-Supports all constellations and frequencies:

GPS: L1 C/A, L1C, L2C, L2 P, L5

GLONASS: L1 C/A, L2C/A

BeiDou: B1I, B2I, B3I

Galileo: E1, E5a, E5b

QZSS: L1C/A, L2C, L5

SBAS: EGNOS, WAS, GAGAN, MSAS, SDCM

-Multi-frequency tracking effectively mitigates ionospheric delays, improving positioning accuracy, especially in open ocean or geomagnetically active regions.

Septentrio’s Unique GNSS+ Technology Suite for Complex Marine Environments

Septentrio’s patented GNSS+ technology ensures signal integrity and data reliability in challenging marine surveying scenarios:

-AIM+: Industry-leading anti-jamming and anti-spoofing technology that effectively suppresses radio frequency interference from shipboard radars, communication equipment, or other sources, ensuring signal purity.

-FUSE+: Deeply fuses RTK positioning with IMU data, enabling precise heading, pitch, and roll measurement based on a single antenna and supporting high-quality dead reckoning, which is key for dynamic platform measurement.

-APME+: A posteriori multipath estimator that significantly reduces GNSS signal reflections from ship decks, superstructures, or nearshore environments.

-LOCK+: Maintains excellent satellite signal tracking stability under ship engine vibrations and wave impacts.

-IONO+: Advanced ionospheric scintillation mitigation technology, ensuring performance in ionospherically active areas like near the equator.

-RAIM+: Receiver Autonomous Integrity Monitoring, providing an additional layer of safety.

These technologies work together to deliver exceptional and quantifiable performance metrics even under adverse conditions:

-RTK-INS Positioning Accuracy (baseline <40 km): Horizontal 0.6 cm + 0.5 ppm, Vertical 1 cm + 1 ppm (typical initialization time 7 seconds), meeting the requirements for high-precision seabed control point measurement.

-Attitude Measurement Accuracy:

RTK Mode: Pitch/Roll accuracy 0.2° (from Integrated Attitude Accuracy table).

INS Velocity Accuracy (RTK Mode): 0.02 m/s, aiding precise Doppler velocity log assistance or motion analysis.

Rugged and Durable, Built for the Marine Environment

-Physical Specifications: Dimensions 102 × 36 × 118 mm, Weight 490 g, compact structure.

-Protection Rating: IP68 fully waterproof and dustproof housing, resistant to wave splash, rain, and salt spray erosion.

-Ruggedness: Compliant with MIL-STD-810G military standards (humidity, dust, shock, vibration), suitable for the harsh demands of shipboard environments.

-Operating Temperature: -30°C to +65°C, ensuring broad applicability from polar to tropical seas.

-Power Supply: Wide voltage input (4.5 – 36 VDC), compatible with shipboard 24V power systems.

-Power Consumption:

Tracking GPS/GLONASS L1/L2: 1.3 W

Tracking all constellations and all frequencies: 1.5 W

Maximum power consumption: 2.5 W

Low power consumption is suitable for long-term observation missions.

Integration of AsteRx SBi3 Pro into Marine Surveying Platforms

Positioning and Attitude Core for Integrated Vessel Survey Systems

As the core sensor for survey vessels, the AsteRx SBi3 Pro provides an integrated position and attitude update rate of up to 10 Hz, combined with latency below 20 ms (98% of samples), ensuring strict synchronization with equipment like multibeam echo sounders, side-scan sonars, and laser scanners, tagging all measurement data with precise spatiotemporal and attitude labels. Event marker accuracy < 20 ns supports precise time synchronization with external devices.

Unmanned Surface Vessel (USV) and Autonomous Underwater Vehicle (AUV) Navigation

Its compact size and low power consumption make it highly suitable for integration into USVs and AUVs. The single-antenna solution simplifies installation. The FUSE+ technology provides precise heading and attitude, combined with dead reckoning capability, ensuring continuous and reliable navigation and control for USVs/AUVs in GNSS signal-limited areas (e.g., fjords, under bridges, during underwater recovery).

Ocean Buoy and Dynamic Water Level Station Monitoring

The wide voltage input and low power consumption design make it ideal for solar-powered buoy systems. High-precision RTK positioning can be used to monitor minute position changes of buoys for analyzing currents and tides; precise attitude data can correct measurements from mounted wave and meteorological sensors.

Coastal and Harbor Engineering Precision Surveys

In engineering surveys for ports, docks, and cross-sea bridges, APME+ technology effectively mitigates multipath effects from complex structures. The rugged design ensures stable operation in environments with construction vibrations. Interfaces such as Ethernet (supporting PoE), 3 high-speed serial ports (RS232), and USB allow easy integration into engineering survey software or automated mapping systems.

The Septentrio AsteRx SBi3 Pro: Laying the Spatiotemporal Foundation for Precise Marine Spatial Information

Enhancing Marine Survey Data Quality and Credibility

By providing continuous, reliable, high-precision position and attitude data, it fundamentally improves the geometric accuracy of acoustic, optical, and other marine detection data, enhancing the quality of products like seabed terrain models, marine gravity fields, and magnetic fields, and strengthening their scientific value and credibility for engineering applications.

Simplifying System Integration and Data Processing Workflow

The intuitive Web User Interface, automatic lever arm compensation tool, comprehensive data protocol support (SBP, NMEA 0183 v3.01/v4.0, RTCM 3.x MSM, CMR+), and detailed API documentation significantly reduce the difficulty and workload of integrating high-precision positioning and attitude systems into complex marine surveying systems. Support for the NTRIP client facilitates access to land-based or satellite-based augmentation services.

A Reliable Choice for Future Marine Observation

The AsteRx SBi3 Pro integrates cutting-edge technologies like anti-interference and multi-sensor fusion. Its ruggedness and long-term stability provide a future-proof positioning and attitude solution for various marine observation platforms (from manned vessels to unmanned systems). The product complies with international certifications such as RoHS, WEEE, CE, FCC.

Which GNSS/INS receiver is suitable for marine survey vessels?

The Septentrio AsteRx SBi3 Pro is an ideal choice for marine surveying applications. It provides centimeter-level RTK positioning accuracy (horizontal 0.6 cm + 0.5 ppm) and precise 3D attitude measurement (pitch/roll accuracy 0.2° in RTK mode). Its IP68 waterproof housing, AIM+ anti-jamming technology, and powerful dead reckoning capability (e.g., 0.306 m horizontal error after 10-second outage) are specifically designed to handle marine environmental challenges like vessel vibration, signal obstruction, and multipath interference.

Why does marine surveying require a GNSS/INS integrated system?

Because vessels constantly experience roll, pitch, and yaw motions due to waves. These attitude changes directly affect measurement data from onboard sensors (like echo sounders). GNSS provides absolute position, while the INS (Inertial Navigation System) can measure these attitude changes at high frequency and continuously, and compensate for brief GNSS signal loss (dead reckoning), thereby ensuring all marine survey data has a unified and precise spatial reference. For example, the AsteRx SBi3 Pro can keep horizontal positioning error within approximately 3 meters for up to 30 seconds after a GNSS outage.

What specific role does AIM+ technology play in the marine environment?

The marine environment, especially on working vessels, harbors numerous potential sources of GNSS interference, such as radar, radio communication equipment, and power system noise. AIM+ technology actively monitors and suppresses these interference signals, including intentional spoofing, ensuring the GNSS receiver outputs reliable, unadulterated position data under any conditions. This is crucial for safeguarding survey operations and data integrity.

How fast is the startup and reacquisition of the AsteRx SBi3 Pro?

This receiver features fast startup and signal reacquisition capabilities, ensuring operational efficiency:

Cold start (no almanac, no approximate position): < 45 seconds

Warm start (ephemeris and approximate position known): < 20 seconds

Average signal reacquisition time: Approximately 1 second

This ensures rapid recovery of high-precision positioning after device restart or brief signal loss.

Summary

-High-precision positioning: Provides RTK-INS centimeter-level positioning accuracy (horizontal 0.6 cm + 0.5 ppm, vertical 1 cm + 1 ppm).

-Precise attitude measurement: Pitch/roll accuracy of 0.2° in RTK mode; maintains high performance during dead reckoning (e.g., heading 0.35°, pitch/roll 0.06° after 10 seconds).

-Continuous and reliable navigation: Built-in high-performance IMU (gyroscope bias instability 2.7°/hr) supports dead reckoning, keeping horizontal error < 3.1 meters within 30 seconds of GNSS outage.

-Powerful signal and anti-interference: 544 channels support all-constellation, multi-frequency GNSS. Integrates GNSS+ technology suite including AIM+, APME+, LOCK+ to ensure reliability in complex electromagnetic and dynamic environments.

-Rugged marine-grade design: IP68 waterproof and dustproof, compliant with MIL-STD-810G military standard, operating temperature -30°C to +65°C, suitable for harsh marine environments.

-High performance and easy integration: 10 Hz update rate, <20 ms latency, provides rich interfaces including Ethernet (PoE), multiple serial ports, USB, and supports various data formats like SBP, NMEA, RTCM, CMR+.

-Rapid deployment response: Cold start <45 seconds, warm start <20 seconds, average reacquisition 1 second, meeting the needs of efficient operations.