Split-beam echosounder data from keel-mounted EK60 during PolarFront 2022-05 cruise

Cruise report: Hull-mounted EK60 The keel-mounted Simrad EK60® split-beam echosounder continuously recorded hydroacoustic data at 18, 38, and 120 kHz. The ping rate was set to 1.5 seconds and pulse length to 1,024 µs. The echosounder was calibrated annually using the standard sphere method (Demer et al., 2015). A Seabird 911 Plus CTD® recorded temperature and conductivity regularly throughout the transects from which we could derive profiles of temperature and salinity, sound speed (Mackenzie, 1981), and the coefficient of absorption at each frequency (François and Garrison, 1982).巡航报告：船底安装式EK60。采用龙骨处安装的西姆拉德（Simrad）EK60®分体波束回声测深仪，以18 kHz、38 kHz及120 kHz的频率连续采集水声数据。该设备的脉冲发射间隔设为1.5秒，脉冲宽度设为1024微秒。本回声测深仪每年均采用标准球体校准法（Demer等，2015）完成校准。西毕得（Seabird）911 Plus 温盐深（Conductivity Temperature Depth，CTD）剖面仪沿全部测线全程定时记录温度与电导率数据，据此可推导得到温度、盐度、声速（Mackenzie，1981）以及各频率下的声吸收系数（François与Garrison，1982）的垂直剖面。