2019_programme: SEABED SCATTERING CROSS SECTION ESTIMATION USING THE RESON SEABAT T50: A NUMERICAL EVALUATION OF THE FOOTPRINT ERROR WHEN USING A ZERO-SLOPE ASSUMPTION IN THE ALONG-TRACK DIRECTION

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  • Session: 18. Multibeam Echo Sounding: Bathymetry and sediment Classification
    Organiser(s): Simons Dick, Snellen Mirjam 
  • Lecture: SEABED SCATTERING CROSS SECTION ESTIMATION USING THE RESON SEABAT T50: A NUMERICAL EVALUATION OF THE FOOTPRINT ERROR WHEN USING A ZERO-SLOPE ASSUMPTION IN THE ALONG-TRACK DIRECTION
    Paper ID: 814
    Author(s): Wendelboe Gorm
    Presenter: Wendelboe Gorm
    Presentation type: oral
    Abstract: The bottom scattering cross section estimated by the RESON SeaBat T50 multibeam echosounder (MBES) includes an estimate of the insonified area, which is obtained by assuming the seabed has a vanishing slope in the along-track direction. In this paper, the validity of this assumption is investigated for different along-track slopes, depths, and continuous wave (CW) pulse durations using a numerical model. It is demonstrated how the errors are largest around normal incidence and rapidly decrease as steering angle increases. The errors can be reduced by increasing the CW pulse duration. For example, at 400kHz, a 40μs CW pulse transmitted over a nadir-depth of 35m will, for seafloors with along-track slopes of 5% and 15%, yield errors of 1.5 and 5dB, respectively. If, however, the duration of the CW pulse is increased to 100μs, the resulting errors are reduced to 0.05 and 1.5dB, respectively. Finally, a brief description is given of how the estimated footprint areas can be removed from the estimated scattering cross section values and replaced by the user’s own estimates.
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  • Corresponding author: Dr Wendelboe Gorm
    Affiliation: Teledyne-RESON
    Country: Denmark
    e-mail:

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