2025_programme: TES measurements of various objects

• Day: June 17, Tuesday
    Location / Time: D. CHLOE at 10:10 - 10:30
• Last minutes changes: -
• Session: 17. Target Echo Strength – Measurements and Modelling
  Organiser(s): David Nunn 
  Chairperson(s): David Nunn 
• Lecture: TES measurements of various objects [Invited]
  Paper ID: 2263
  Author(s): Arne Stoltenberg, Ingo Schaefer
  Presenter: Arne Stoltenberg
  Abstract: The Target Echo Strength (TES) of an object under water is a measure for its reflectance of sound intensity in a certain frequency range. It is strongly depending on its material, structural design and other features. In natural waters horizontally propagating reflected sound waves have the smallest transmission loss and transport information of objects hit to considerable distances. This must be considered, when estimating angle-dependent TES of any object.\n\nSometimes it is useful to increase the TES of objects to heighten their visibility (i.e. to marine mammals). There is an approach to increase the TES of fisher nets by resonators in the frequency range used by harbor porpoises to decrease the accidental bycatch of these species.\n\nTES of simple objects nowadays can be numerically modelled very efficiently. TES experiments under controlled conditions are necessary as a reference in order to further improve the methods of numerical TES modelling. The experimental validation of the TES of smaller objects is easily done in water tanks, middle (< 1 – 3 m) sized and bigger objects are more challenging due to the (depending on the frequencies) necessary distances to fulfill the far field condition. Just little more complex models (i.e. a TES reference body designed as a corner icosahedron) require more effort in numerical modelling and experimental setup to estimate their most prominent features.\n\nIn Germany there is a TES range in the Great Lake of Plön that is actually reenabled to measure bigger TES models like the M32x models build for benchmarks within the the international CSSM project named TESSMEx. First results are given.\n\n
• Corresponding author: Dr Arne Stoltenberg
  Affiliation: Senior Scientist
  Country: Germany