UACE2017 Proceedings: Mapping Unexploded Ordnance (UXO) using Interferometric Synthetic Aperture Sonar

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  • Session:
    Underwater Unexploded Ordnance (UXO) Detection and Remediation
  • Paper:
    Mapping Unexploded Ordnance (UXO) using Interferometric Synthetic Aperture Sonar
  • Author(s):
    Roy Edgar Hansen, Torstein Olsmo Sæbø, Ole Jacob Lorentzen, Stig Asle Vaksvik Synnes
  • Abstract:
    After World War II (WWII) chemical munitions were deposited in the Skagerrak strait in the Norwegian trench, in deep waters between Norway and Denmark. The procedure was to load the munitions onto large cargo ships, position these, and sink the ships either by scuttling or by the use of explosives. It has been estimated that between 41 000 and 48 000 tons of chemical munitions were deposited in this area. In collaboration with the Norwegian Coastal Administration, the Norwegian Defence Research Establishment (FFI) conducted cruises in 2015 and 2016 using a HUGIN autonomous underwater vehicle (AUV) equipped with a HISAS interferometric synthetic aperture sonar (SAS). The main goals were to locate and image the ships, determine their conditions, and find areas where dangerous cargo from the ships was spread out. \nThe benefit of interferometric SAS technology is the ability to provide imagery and bathymetry at both very high resolution and long range. This makes SAS technology well suited for mapping of larger areas and searching for large and small objects of interest. The Skagerrak survey consists of 24 AUV dives where approximately 450 km2 were covered in 4 x 4 cm theoretical resolution. 54 wrecks were found, and 36 of these are believed to be part of the chemical munitions dumpsite. Of the shipwrecks found, many have suffered severe damage, and their cargo is spread out around the shipwrecks. \nIn this paper, we consider SAS technology for the search of unexploded ordnance (UXO) at the seabed. We investigate key parameters for understanding, planning, executing, and processing tailored search operations. We show example images of ship wrecks and UXOs at various sonar ranges from the Skagerrak dumpsite.
  •   Download the full paper

Contact details

  • Contact person:
    Dr Roy Edgar Hansen
  • e-mail:
  • Affiliation:
    Norwegian Defence Research Establishment (FFI)
  • Country:
    Norway

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