Backscatter calibration of high-frequency multibeam echosounder using a reference single-beam system, on natural seafloor

The calibration of multibeam echosounders for backscatter measurements can be conducted efficiently and accurately using data from surveys over a reference natural area, implying appropriate measurements of the local absolute values of backscatter. Such a shallow area (20-m mean depth) has been defined and qualified in the Bay of Brest (France), and chosen as a reference area for multibeam systems operating at 200 and 300 kHz. The absolute reflectivity over the area was measured using a calibrated single-beam fishery echosounder (Simrad EK60) tilted at incidence angles varying between 0° and 60° with a step of 3°. This reference backscatter level is then compared to the average backscatter values obtained by a multibeam echosounder (here a Kongsberg EM 2040-D) at a close frequency and measured as a function of angle; the difference gives the angular bias applicable to the multibeam system for recorded level calibration. The method is validated by checking the single- and multibeam data obtained on other areas with sediment types different from the reference area.

Keyword(s)

Calibration, Seafloor backscatter, Multibeam echosounder, Single-beam echosounder

Full Text

FilePagesSizeAccess
Publisher's official version
193 Mo
Author's final draft
523 Mo
How to cite
Eleftherakis Dimitrios, Berger Laurent, Le Bouffant Naig, Pacault Anne, Augustin Jean-Marie, Lurton Xavier (2018). Backscatter calibration of high-frequency multibeam echosounder using a reference single-beam system, on natural seafloor. Marine Geophysical Research. 39 (1-2). 55-73. https://doi.org/10.1007/s11001-018-9348-5, https://archimer.ifremer.fr/doc/00429/54016/

Copy this text