2023_programme: TES measurements in TNO basin

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  • Session: 14. Target Echo Strength – Measurements and Modelling
    Organiser(s): David Nunn
  • Lecture: TES measurements in TNO basin [invited]
    Paper ID: 2084
    Author(s): van der Burg Dennis, Gaida Timo Constantin, Berkhoff Arthur, Oppeneer Victor, Fillinger Laurent
    Presenter: Gaida Timo
    Abstract: The Target Echo Strength (TES) is a far field property of an object that characterises the strength of the acoustic return from an active sonar. Its measurement in the far field is complicated by the need to account for propagation loss, reverberation and ambient noise. In order to overcome these limitations, TNO is developing TES measurement techniques in the near field applicable in a semi-anechoic basin. This is described using two examples: the measurement of the monostatic TES of a scale-model, and the extension of the method to evaluate reflection and transmission properties of plates in a bistatic measurement set-up.\nIn the first part, M32T, a 1.5 meter long scale-model from the TESSMEX project that includes various shapes and internal parts is considered. It is measured using a directive source in the 10-40kHz frequency band using 19 hydrophones located over an arc circle. The object is continuously rotated to measure it from multiple aspects. The data processing is briefly described and illustrated with simulations and experimental results demonstrating the extrapolation of the TES into the far-field and the reconstruction of an image of the object that allows identification of its acoustic hot-spots. \nIn the second part, the adaption of this technique to measure specular and non-specular properties of plates at various incident angles is discussed. The goal is to compensate for the geometric diffraction effect in order to evaluate reflection and transmission coefficients. The steps undertaken in this direction regarding measurement methodology and data processing are presented and illustrated using simulated data.
  • Corresponding author: Dr Laurent Fillinger
    Affiliation: TNO
    Country: Netherlands
    e-mail:

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