This dataset provides a harmonised, inter-calibrated collection of multi-platform oceanographic observations acquired during the FOCUS/SWOT-ACC voyage (IN2023_V07) in the Southern Ocean during 2023–2024. Observations were collected in the vicinity of the Antarctic Circumpolar Current Polar Front and its standing meander downstream of the Southeast Indian Ridge using multiple observing platforms, including ship-based CTD casts, Triaxus surveys, autonomous gliders, EM-APEX profiling floats and BGC-Argo floats.

The source datasets had previously undergone platform-specific processing and initial quality control by the relevant data providers. An additional cross-platform consistency assessment and inter-calibration was subsequently undertaken to improve comparability among the observing systems. Temperature, salinity and dissolved oxygen were evaluated using overlapping or closely matched observations, with systematic offsets assessed relative to instrument accuracy, the variability of the observed differences, and the persistence of offset sign. Corrections were applied where the observed differences were considered sufficiently systematic and robust.

The resulting data product contains the processed and inter-calibrated observations in NetCDF format and is intended to provide a consistent, analysis-ready dataset for multi-platform studies of hydrographic structure, water-mass variability and frontal processes in the Polar Front region. The original source datasets remain available through their respective institutional and community repositories. Documentation accompanying this dataset describes the source data, inter-calibration methodology, applied corrections, data provenance and relevant limitations.