http://bolin.su.se/data/jakobsson-2020-tvarminne-1 Martin Jakobsson Bolin Centre Database 2020 Datafile Marine Bathymetry Multibeam bathymetry Groundwater Seafloor morphology Earth science > Oceans > Bathymetry/seafloor topography Martin Jakobsson 2020-01-02T11:28:35+00:00 English 1 None, but please cite Jakobsson et al. (2020) The bathymetric data is provided as a processed grid at a resolution of 50x50 cm in reference to the UTM Zone 34 projection. Data are available in one GeoTIFF (.tif) file (2.4 MB). The data is resolved to instantaneous sea level, hence no reference to a geodetic vertical datum is made. The multibeam bathymetric data available as a processed grid were acquired in 2017 during a survey with RV Electra (24.3 m long). A Kongsberg EM2040 0.4°x0.7°, 200-400 kHz, multibeam echo-sounder is hull mounted in RV Electra. These data were acquired using the 400 kHz mode. Position, heading and attitude data were acquired from Kongsberg-Seatex Seapath 330+ navigation units (GPS and GLONASS) with attached MRU5+ motion and reference sensors. Real-Time Kinematic (RTK) corrections were received provided over the internet by <a href="https://www.maanmittauslaitos.fi/en/node/1881">FinnRef</a>. Positions have horizontal accuracies estimated to be better than ±10 cm and slightly coarser vertical accuracies. A Valeport MiniSVP sound velocity probe was used at discrete stations to acquire sound speed profiles. In addition, RV Electra has an AML sound velocity probe mounted near the transducer for continuous reading of surface sound speed. The data were processed using <a href="https://www.qps.nl/">QPS Qimera</a> (version 1.7.2).