Underwater acoustic positioning systems locate and track submerged vehicles, instruments, divers, and infrastructure where GNSS signals are unavailable. Using acoustic travel time, phase, or angle measurements, these systems calculate range and bearing between subsea targets and known reference points.
This page showcases leading manufacturers underwater acoustic positioning systems, including USBL, SBL, and LBL systems for offshore and oceanographic applications.
Read the Technology Overview
High-Performance Instruments, Sensors & Technologies for Exploring & Monitoring Subsea Environments
High-Accuracy Inertial Sensors & Acoustic Positioning Systems for Marine, Maritime & Offshore Applications
Cutting-Edge Underwater Imaging & Positioning Solutions for Subsea Exploration
Underwater Acoustic Tracking & Recovery Solutions for Mission-Critical Subsea Assets
Innovative Autonomous Underwater Vehicle Solutions for Subsea Survey, Science & Security Applications
Innovative, High-Performance Underwater Sensing Technologies for the Marine Industry
Innovative Subsea & Marine Navigation, Positioning & Survey Solutions
If you design, build or supply Underwater Acoustic Positioning Systems, create a profile to showcase your capabilities and connect with visitors who have an active requirement for your solutions.
Underwater acoustic positioning systems locate submerged vehicles, instruments, structures, divers, and other assets where Global Navigation Satellite System (GNSS) signals cannot reach. Acoustic travel time, signal phase, or angle measurements determine range, bearing, or both between known reference points and an underwater target. Surface GNSS, vessel attitude, depth, timing, and sound-speed data are then combined to calculate a local or georeferenced subsea position.
An underwater acoustic positioning system may provide an independent fix or correct drift within a broader navigation solution. Performance depends on geometry, range, alignment, platform motion, timing, signal quality, multipath, obstruction, and sound-speed variation. Selection should reflect accuracy, depth, update rate, mission duration, environmental conditions, and available infrastructure.
Acoustic positioning systems are generally classified by the spacing and arrangement of their transducers, transponders, responders, or seabed reference points.
Subsonus USBL Underwater Acoustic Positioning System by Advanced Navigation
Ultra-short baseline acoustic positioning systems use a compact vessel-mounted array to determine the range and direction of a subsea transponder or responder. Range is derived from acoustic travel time, while direction is calculated from phase or time differences across the array. Measurements are combined with surface position, heading, and attitude. Calibration, pole stability, lever-arm offsets, vessel motion, and acoustic conditions affect performance.
A short baseline acoustic positioning system uses several transducers installed across a vessel, structure, or platform. Their separation allows target position to be calculated from measured ranges or timing differences. Accuracy depends on surveyed transducer locations, baseline length, geometry, synchronization, and motion compensation.
A long baseline acoustic positioning system uses multiple transponders at surveyed seabed positions. A vehicle or instrument measures ranges to these references to calculate its position within or near the array. LBL provides stable, repeatable positioning with less dependence on surface-vessel location, but requires deployment, calibration, battery management, and recovery.
Sparse LBL configurations reduce the number of fixed seabed references by combining acoustic ranges with inertial, velocity, depth, or vehicle-motion data. This can reduce mobilization time and seabed equipment. Lower geometric redundancy increases reliance on vehicle trajectories, synchronization, sensor fusion, outlier rejection, and uncertainty monitoring.
Underwater acoustic systems support scientific research, subsea engineering, survey operations, diver tracking, and vessel control whenever the position of a submerged asset must be established.
Hydrographic teams use acoustic positioning to track towfish, Remotely Operated Vehicles (ROVs), sampling platforms, and seabed instruments. Position data links measurements to coordinates, records deployment locations, and supports equipment relocation or recovery.
Water-column research may require tracking profilers, cameras, nets, samplers, and Autonomous Underwater Vehicles (AUVs). Acoustic positioning reconstructs sampling paths and repeated transects. Update rate, range, power, accuracy, and uncertainty should match the platform and objectives.
Marine archaeology projects use acoustic positioning to georeference vehicles, imaging systems, divers, tools, and recovered objects. Environmental monitoring uses similar methods when revisiting habitats, sediment stations, contamination sites, or long-term sensors. Repeatable positioning helps separate environmental change from survey or placement differences.
Subsea construction teams use acoustic positioning to guide vehicles, tooling, and sensors around cables, pipelines, foundations, wells, and other assets. Position data supports placement, inspection, metrology, touchdown monitoring, and as-built surveys. High-precision work may combine acoustic, inertial, Doppler velocity, depth, sonar, and optical data.
An acoustic system can provide a relative reference between a surface vessel and a fixed or mobile subsea transponder. This may support Dynamic Positioning (DP) near subsea assets. Operators should consider continuity, latency, geometry, redundancy, interference, alarm limits, and undetected bias.
A complete underwater acoustic positioning system may include the following components:
Final accuracy also depends on transducer offsets, angular alignment, turnaround delays, coordinate frames, clock synchronization, and processing quality.
Acoustic positioning is often integrated with other navigation sensors to improve continuity, stability, and accuracy between acoustic updates:
These inputs may be combined through loosely or tightly coupled sensor fusion. Robust systems monitor residuals, reject invalid measurements, estimate uncertainty, and define behavior when updates are lost.
The configuration of an acoustic positioning system must reflect vehicle size, power, operating depth, motion, acoustic field of view, and communications architecture.
Remotely Operated Vehicles (ROVs) commonly carry a transponder or responder for inspection, sampling, intervention, and construction. Acoustic data may update the vehicle’s Inertial Navigation System (INS). Integration should account for tether forces, shading, thruster noise, attitude, sensor offsets, and coordinate frames.
Autonomous Underwater Vehicles (AUVs) use acoustic updates to correct drift without surfacing for GNSS. They may navigate relative to seabed beacons, a support vessel, or an unmanned surface platform. Update rate must be balanced against power, channel access, range, speed, and INS performance.
Unmanned Surface Vessels (USVs) can carry GNSS, attitude sensors, and acoustic transceivers to track submerged assets. Repositioning can improve geometry, follow an AUV, or extend coverage. Cooperative operations require synchronization, reliable communications, collision avoidance, and shared coordinate frames.
Towed vehicles move independently of the vessel because of cable shape, current, depth, and maneuvers. Direct acoustic positioning is more reliable than cable-length estimates alone. Combining vessel navigation, tow measurements, depth, layback, and acoustic fixes strengthens the position record.
Current development is focused on reducing fixed infrastructure, improving navigation continuity, and obtaining more information from each acoustic transmission:
These developments are expanding system capability while increasing the importance of synchronization, calibration, cybersecurity, uncertainty estimation, and efficient acoustic channel management.
Searching Companies & Products
Subscribe to the Weekly eBrief
The latest engineering and technical developments straight to your inbox - join thousands of engineers who receive it.
