Swath-bathymetric mapping

The main objective of the bathymetric working group was to perform high resolution multibeam surveys during the entire cruise for geomorphological interpretation, to locate geological sampling sites, to interpret magnetic and gravimetric measurements and to expand the world database for oceanic mapping. Precise depth measurements are the basis for creating high resolution models of the sea surface. The morphology of the seabed, interpreted from bathymetric models, gives information about the geological processes on the earth surface. The main characteristic of the deep water sounding system Atlas Hydrosweep DS-2 is a coverage angle of up to 120°, which results in a depth profile with a length of 3.4 times the water depth perpendicular to the ship's long axis. Most of the time a coverage angle of 100° was applied. The acoustic signal, generated by the hull mounted transducer, has a frequency of 15.5 kHz and allows measurement up to full ocean depth. Based on the acoustic pulse 240 depth measurements with individual opening angles of about 2.3° (in deep water operation) and an accuracy of approximately 1 % of water depth were derived. In addition, the echo amplitudes were converted to multibeam sidescan (4094 pixels per swath) and angular backscatter data (59 values per swath).