Acoustic data collected by wideband autonomous transceiver (WBAT, 35 to 445 kHz) during RV Sarmiento de Gamboa cruise 'Sustainable Management of Mesopelagic Resources' (SUMMER) in 2020 to the Mediterranean

A lowerable acoustic wideband autonomous transceiver (WBAT) was deployed during the 2020 SUMMER (Sustainable Management of Mesopelagic Resources) Mediterranean cruise (30 September 2020 to 18 October 2020) aboard the R/V Sarmiento de Gamboa. In total 31 drops were conducted with a depth range from 0 to 500 m to make close up broadband observations of scattering layers. Some of the deployments were done in parallel to ship-based stationary EK80 recordings in fequency modulated mode. There were 4 transducers (with nominal frequencies at 38, 120, 200 and 333 kHz) used with a frequency band covering 35 to 445 kHz. A maximum volume of 100 MB per individual raw file was used, and the recording range was set to 100 m for all frequencies. Transmitted power for 4 transducers from 38 to 333 kHz was set to 225, 125, 75 and 25 W, respectively. Calibration data were recorded in part of the deployments using a 33 mm tungsten sphere. Raw power (W), number of transducer segments and transceiver impedance (Ohm) were stored in raw proprietary Simrad format (.raw). The raw files were recorded according to the UTC-01:00 time zone, the metadata below use UTC+00:00.