Multi-Resolution backscatter grids of the Naples and Pozzuoli Gulf and the Amalfi Coastal Area collected during cruise Jamme_Gaia22, 2022

During the Jamme_Gaia22 cruise, held from September 27th to October 20th, 2022, multi-beam data were collected using three different MBES systems: the Kongsberg EM2040-04 MKII (0.4° x 0.7°) for water depths between 50 and 150 meters, the Kongsberg EM712 (0.5° x 1°) for depths between 150 and 1000 meters, and the Kongsberg EM304 MKII (1° x 1°) for depths greater than 1000 meters. The MBES backscatter data were processed using QPS Fledermaus Geocoder Tool (FMGT) v.7.10.2. The processed data (.gsf) underwent backscatter corrections, beam pattern correction, and angle-varying gain (AVG) adjustments. FMGT then utilized the sonar’s navigation data (including XY coordinates, roll, heading, pitch, and heave) to enhance spatial accuracy. The bathymetric Digital Terrain Model (DTM) generated in Qimera was used as a reference grid to further refine backscatter corrections by determining the topographic slope. The corrected bathymetry from the source files (GSF) was used to accurately geo-reference snippet traces from single pings to the seafloor with correct scaling. Finally, the backscatter snippets were mosaicked using the "No Nadir possible, 25% overlap" algorithm to reduce banding, and 30-40% line blending was applied to blend overlapping pixels. The mosaics were gridded at various resolutions, with dB values cropped to ± 3σ and mapped to an 8-bit scale. The final mosaics were exported as "One merged Colored GeoTIFF format". The backscatter grids are in ESRI ASCII grid format.