Two Polarstern expeditions were conducted in 1995 (ANT-XII/4) and 2001 (ANT-XVIII/5a) to the Bellingshausen Sea and Amundsen Sea and the suspected Eltanin meteorite impact in the SE-Pacific. A survey of the sediment distribution and its acoustic structure along the cruise track was performed. The seafloor topography was sampled using the multibeam sonar system Hydrosweep DS2 which operates on a frequency of 15.5 kHz. The resulting AWI Bathymetric Chart of the Eltanin Meteorite Impact Area is based on a Digital Terrain Model of this area. The mapping was performed using ArcGIS. The Eltanin impact area which covers the 4.100 m high Freden Seamount is visualized by one overview sheet of the scale 1:200,000 and four 1:100,000 subsheets.
Raw data editing and cleaning was performed using Caris HIPS. Within ArcGIS the inverse distance weighting interpolator applying a search radius depending on the number of input points, but with a maximum size of 500 meters was utilized to compute the DTM. The grid size of the DTM was chosen at 100 meter, based on the average point density. Because of the moderate noise present after the computation of the DTM a slope-depending binomial -filtering was applied. The accuracy of multibeam depth measurements is estimated between 0.5 to 1.0 % of the water depth. The differences between gridded and raw data are within this limit.