Shipboard ADCP current measurements (75 kHz) during RV MARIA S. MERIAN MSM141/2

DOI

Current velocities of the upper water column along the cruise track of R/V Maria S. Merian cruise MSM141/2 were collected by a vessel-mounted 75 kHz RDI Ocean Surveyor ADCP. The ADCP transducer was located at 6.0 m below the water line. The instrument was operated in narrowband mode (WM10) with a bin size of 8.00 m, a blanking distance of 8.00 m, and a total of 100 bins, covering the depth range between 22.0 m and 814.0 m. Attitude data from the ship's motion reference unit were used by the data acquisition software VmDAS internally to convert ADCP beam velocities to geographic coordinates. The Python toolbox OSADCP (version 2.2.0) was used for data post-processing. Acoustic Interferences were identified based on outliers in the ADCP echo intensity data. Echo intensity data were cleaned accordingly and affected velocity cells were flagged to be removed prior ensemble-averaging. Upper-bin single-ping ADCP velocities affected by low echo-intensity were identified using a robust covariance-based outlier detection in velocity-backscatter space and removed when exceeding a chi-square confidence threshold. The ship's velocity was calculated from position fixes obtained by the Global Navigation Satellite System (GNSS), taking into account lever arms of ADCP transducer and GNSS antenna. Accuracy of the derived water velocities mainly depends on the quality of the position fixes and the ship's heading data. Further errors stem from a misalignment of the transducer with the ship's centerline. Data processing included water track calibration of the misalignment angle (-47.1845° +/- 0.4338°) and scale factor (1.0059 +/- 0.0105) of the measured velocities. The velocity data were averaged in time using an average interval of 60 s. Depth cells with ensemble-averaged percent-good values below 25% are marked as 'bad data'.

Identifier
DOI https://doi.org/10.1594/PANGAEA.992810
Related Identifier References https://doi.org/10.1594/PANGAEA.992811
Related Identifier IsDocumentedBy https://doi.org/10.5281/zenodo.14532654
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.992810
Provenance
Creator Kopte, Robert ORCID logo; Nitsche, Frank
Publisher PANGAEA
Publication Year 2026
Rights Creative Commons Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Representation
Resource Type Dataset
Format text/tab-separated-values
Size 5793308 data points
Discipline Acoustics; Engineering Sciences; Mechanical and industrial Engineering; Mechanics and Constructive Mechanical Engineering
Spatial Coverage (-34.977W, -17.126S, -22.676E, 11.609N)
Temporal Coverage Begin 2025-12-11T04:03:00Z
Temporal Coverage End 2025-12-17T17:59:00Z