High-resolution basal topography and basal properties were calculated from two 3x3 km2 radar datasets acquired approximately 50 km upstream of the grounding line of Rutford Ice Stream in West Antarctica. The provided datasets contain several csv-files including the coordinates, bed elevation below the WGS84 ellipsoid and the reflectivity of the bed reflection. The X and Y coordinates are projected in EPSG:3031 - WGS 84 / Antarctic Polar Stereographic coordinate system. Radar data were acquired between December 2017 and late January 2018 using the British Antarctic Survey''s ground-based DELORES system as part of the BEAMISH project. Data acquisition and processing was compliant with 3D processing and migration. Radar data were frequency filtered and 3D migrated (using a 3D Kirchhoff Time Migration approach in SeisSpace/ProMAX (LGCHalliburton Software) and migration velocity of 0.168 m ns-1), followed by the picking of the bed reflection using Petrel (Schlumberger Software). For the interpretation of variation of bed properties, basal reflectivity was calculated as described in Schlegel et al., 2022 and Schlegel et al., 2024.

This work was funded by NERC AFI award numbers NE/G014159/1, NE/G013187/1 and NE/F015879/1, and NERC National Capability Science: Strategic Research and Innovation Short Projects. Geophysical equipment was provided by NERC''s Geophysical Equipment Facility, loan number 887. We thank BAS Operations and N. Gillett for fieldwork support and B. Craven for software support. University of Leeds acknowledges support of this work by Landmark Software and Services, a Landmark Company and use of SeisSpace/ProMAX via the Landmark University Grant Program, Agreements 2004-COM-024982, 2008-CON-010888 and subsequent renewals. The British Antarctic Survey acknowledges support of this work by Landmark Software and Services, a Landmark Company.