SEP Hydrographic Invests in Applied Acoustics Pyxis INS + USBL System

Posted 12 December 2025

By heather Heather Blackford

SEP Hydrographic has acquired an Applied Acoustics' Pyxis INS + USBL system, marking a significant advancement in the company's subsea positioning capabilities for nearshore and coastal operations.

The factory-calibrated system eliminates traditional USBL calibration requirements, delivering both operational efficiency gains and measurable accuracy improvements across our survey projects.

More Efficient Mobilisations

Traditional USBL systems require full calibrations involving deploying a beacon on the seabed. In nearshore survey environments, this process often depends on specific tidal conditions and favourable weather, with calibration alone typically accounting for a full day of vessel mobilisation. Waiting for suitable conditions could extend mobilisation periods further.

As a company specialising in nearshore survey operations on smaller vessels, all beacon deployments and recoveries were carried out manually, bringing associated safety considerations.

The Pyxis system addresses these limitations through its integrated approach. Factory calibration of all acoustic and chassis alignments means field work is limited to installation-specific INS alignment only.

The result: no seabed beacon deployment required, no tidal window dependencies, and safer mobilisations overall.

Performance Gains

Early operational data demonstrates clear performance benefits:

  • Mobilisation efficiency: Average one-day time saving per deployment
  • Positional accuracy: Sub-meter accuracy achieved when resolving raw Side Scan Sonar positioning.
  • Target location precision: Raw positioning variance between MBES and SSS data as low as 0.24m

SEP Hydrographic Director Paul Dodd commented:

"We saw a demonstration of the Pyxis at Ocean Business and were immediately interested in the factory-calibrated approach. Removing the need to deploy a beacon on the seabed makes our mobilisations both safer and more efficient, and the early accuracy results speak for themselves."

About the Pyxis INS + USBL

The Pyxis INS + USBL combines Applied Acoustics' proven USBL technology with SBG Systems' Navsight Apogee Marine INS. As a tightly coupled, factory-fitted system, it is designed for rapid deployment and delivers survey-grade subsea positioning performance.