Multibeam sonar images of a fish farm

This dataset consists of Images produced from a Seapix-R multibeam echosounder (MBES) pointed at a fish farming cage. The MBES was attached outside the cage on a mounting bracket with a 45 deg downwards tilt, such that most of the cage was within the vertical beamforming capability of the system, with the exception of a small cake-shaped section near the net, 1.5 meters high, extending 5.5 meters into the cage

The MBES can steer acoustic beams at angles of $120^\circ \times 120^\circ$ and operates at a frequency range of 145-155 kHz. The beam aperture of the Seapix-R is 1.6 times 1.6 degreees on the element axis. The dataset was obtained during one data collection event. The trial was conducted at a Lingelaks site in Bergadalen, Norway. The data capture started at 09:22 on April 15 2021, during daylight hours and outside the routine feeding schedule, ensuring minimal disturbances and deviations in behavioural patterns. The range of each image is from 0 to 10 m. The tilt of the swath is 55 deg. The image is captured in the vertical direction.

Backscatter in the images is caused by atlantic salmon swimming in the cage.