http://bolin.su.se/data/oden-petermann-2015-bathymetry-2 Martin Jakobsson, Larry Mayer, Kelly Hogan, Björn Eriksson, Kevin Jerram, Christian Stranne Bolin Centre Database 2021 Datafile Marine Bathymetry Bathymetry Arctic Ocean Multibeam Icebreaker Oden Earth science > Oceans > Bathymetry/seafloor topography > Bathymetry Martin Jakobsson 2021-11-04T14:14:39+00:00 English 2 The bathymetric data are provided as processed grids, divided into survey areas, with a grid cell size of 15 m. The grids are provided both in polar stereographic projection (IBCAO Polar Stereographic, EPSG 3996, true scale at 75 degrees north) and unprojected WGS 84 and in geographic coordinates (latitude and longitude). The horizontal datum is WGS 84 and the vertical datum is instantaneous sea level, implying that the vertical level has not been corrected for tides. For each projection, the bathymetric data grids are available in four formats: GeoTiff, netCDF, ASCII XYZ and ESRI Arc ASCII grid. Data are also illustrated as JPEG images. The data were acquired in summer 2015 from Swedish icebreaker (IB) Oden during the Petermann 2015 expedition. A Kongsberg EM122 1°⁠ × 1°⁠, 12 kHz, multibeam echo-sounder was hull-mounted in IB Oden. Position, heading and attitude data were received from a Kongsberg-Seatex Seapath 320 navigation unit (GPS and GLONASS) with attached MRU5 motion sensor. The exact speed of sound at the multibeam transducers was provided by a Valeport Mini SVS/T sound speed and temperature sensor mounted in the sea-chest in Oden’s hull, close to the multibeam transducer arrays. This was interfaced with the multibeam system directly. In addition, sound speed profiles for the entire water column were provided by CTD (Conductivity, Temperature, Depth) stations as well as XBT (Expendable Bathy Thermograph) probes. The data was collected in a mixture of sea-ice conditions, ranging from 5/10 to 8/10 coverage. Navigation was provided by a Seatex Seapath 320 without local augmentation as this is not available in the area. Sound speed correction was done regularly using data from a Seabird 911+ CTD (conductivity, temperature depth) or Valeport SVP (sound velocity profiler). The Petermann expedition started and ended in Thule Airbase, Greenland, and lasted from July 28 to September 2, 2015. It focused on past variations of the ocean-ice-climate-sea level system to assess how the coupled system has responded to changing climate. Interagency and international collaborations included the US National Science Foundation (NSF), The Ocean Melting Greenland (OMG) project of US National Aeronautics and Space Administration (NASA), the British Antarctic Survey, University NAVSTAR Consortium (UNAVCO), the Polar Geospatial Center (PGC), the Swedish Polar Research Secretariat, and the Geological Survey of Denmark and Greenland.