Underwater Holography

The Underwater Holography solution offers highly accurate acoustic maps based on the sound pressure measured by a hydrophone array close to the hull of submarines and vessels. Together with the far-field radiated noise level prediction capability, it is the ideal tool for applications such as acoustic signature management and noise control of submarines and vessels.

• Different array design schemes adapting to surveyed structure and designated site (dock or open sea)
• Accurately localize noise radiating areas on submarines and vessels
• Far-field acoustic signature prediction capabilities
• Source quantification and ranking via evaluating global and partial radiated power through user-defined polygonal patches
• Estimation of the acoustic impact of local modifications on components
• Geometry and results import/export to Matlab® offering extended processing capabilities
• Calculator tool for results, perfect tool for benchmarking competing solutions

The Underwater Holography solution is found on Near-field Acoustical Holography (NAH). NAH is an experimental method which estimates a complex sound field in the immediate vicinity of the hull, based on the sound pressure measured by a hydrophone array. NAH supports sound intensity calculation, enabling source quantification and source ranking via global and partial sound power computation. Furthermore, the Underwater Holography solution employs different hydrophone array designs, adapting to the curved geometry of the surveyed submarines and vessels to enhance performance.

The Underwater Holography software performs all the computational work involved in the NAH ranging activities:

• Configuring the acquisition system and storing pre-processed data
  • Array definition and management, supporting planar, circular or partial circular, and multi-line hydrophone arrays
  • Test definition, acquisition setting
• Performing basic and advanced data processing functions
  • Spectrum analysis (narrowband, octave band, user-defined band)
  • Acoustic pressure and intensity map
  • Far-field radiated noise level prediction
  • Source ranking and screening
• Displaying results
  • Spectra, color maps, directivity diagrams
  • Linear, logarithmic, narrowband, octave
  • Export to MS Word and Matlab®