Scientific potential of a new 3D multibeam echosounder in fisheries and ecosystem research

• SEAPIX is a new type of MultiBeam echosounder with volume imaging capability.
• SEAPIX allows Bathymetry, BS imaging, TS and SV measurement.
• Data are georeferenced and gathered in a space-time databases.
• SEAPIX is designed to equip fishing boat.

SEAPIX is a new multibeam echosounder (MBES) with an original architecture using a steerable symmetric Mills Cross. This configuration allows to image water column and sea bottom in both athwartship and fore-and-aft direction. Furthermore, steering capability in transmit and receive allows a volume coverage of 120° × 120° under ship with 1.6° × 1.6° beam aperture on the antenna axis. 64 beams are acquired per ping in the frequency range of 145–155 kHz using monochromatic or frequency modulated burst. Transmitted beams are stabilized in roll or pitch according with the transmitted mode and receiving beams are motion compensated using an embedded inertial motion unit. This MBES has been designed to be installed on fishing vessel and to help fishing strategies as long as to provide useable data for fish scientist. First part of this paper describes hardware main characteristics of the SEAPIX. We then describe signal processing and functionalities of SEAPIX. Finally, we illustrate first sea results on typical case.