ADCP current measurements (600 kHz) from autonomous surface vehicle on 05.08.2023 during RV HEINCKE cruise HE626

Ocean velocities were collected by a Teledyne RD Instruments 600 kHz RiverRay ADCP that was mounted on an autonomous surface vehicle Halobates along a predefined transect pattern on August 5th 2023 during RV HEINCKE cruise HE626. The transducer was located at 0.257 m below the water line. The instrument was operated in single-ping, broadband mode with automatically selected bins (ranging from 0.1 - 0.8 m) depending on water depth and a blanking distance of 0.25 m. The velocity of Halobates was calculated from position fixes obtained by the Global Positioning System (GPS). Heading, pitch and roll data from vessel's gyrocompass and the navigation data were used by the data acquisition software ViSea DAS (AquaVision®) internally to convert ADCP velocities into earth coordinates. Accuracy of the ADCP velocities mainly depends on the quality of the position fixes and Halobates' heading data. Further errors stem from a misalignment of the transducer with Halobates' centerline.