Multibeam bathymetry

High-resolution bathymetric data acquisition was performed by Fabbri et al. (2017) in 2014 using a Kongsberg EM2040 multibeam echosounder (Kongsberg Maritime, Horten, Norway) in 1° by 1° beam-width configuration, operating at 300 kHz (Fig. 1). The positioning was performed with a Leica GX1230 GNSS receiver (Leica Geosystems, Heerbrugg, Switzerland) in combination with the swipos GIS/GEO real-time kinematic positioning (Swiss Federal Office of Topography, Swisstopo, Wabern, Switzerland). The survey lines were recorded in a shore-parallel pattern. During processing, all auxiliary sensor data (motion sensor, heading sensor, sound velocity sensor, positioning) are merged, reviewed and manually corrected if necessary. Resulting point clouds were reviewed and different algorithms for rasterizations of the point clouds were tested. For analysis, a gridded data set with a 1 m-cell size was produced.