RV Investigator Voyage IN2018_V05 SBP120 Sub-bottom Profiler Data

This record describes sub bottom profiler data collected on RV Investigator voyage IN2018_V05, 'How does a standing meander southeast of Tasmania brake the Antarctic Circumpolar Current?' which departed Hobart on the 16th October 2018 and returned to Hobart on the 16th November 2018. The objectives of the voyage included: (1) Deployment of a fleet of EM-APEX profiling floats, (2) Deployment of a tall mooring at the crest of a meander in the Polar Front of the Antarctic Circumpolar Current, (3) Full-depth hydrographic survey of the physics and biogeochemistry of the targeted ACC meander, conducting transects across the front and (4) Triaxus transects across and along the front. The Kongsberg SBP120 (sub bottom profiler) was used to acquire data containing the specular reflections at different sediment interfaces below the seafloor. The SBP120 provides a 3° by 3° angular resolution.The echosounder's frequency sweep range is from 2.5 to 7 kHz. The SBP120 was logged for the extent of the voyage between Hobart and Hobart, but was set to passive mode during sensitive VMP deployment periods of the voyage in the ACC, when acoustic silent periods were requested by the science party.Data are stored in *.raw (297 files 5.67 GB) raw and *.seg (292 files 5.65 GB) segy formats at CSIRO.The segy format data had a real time processing stream applied, which applies gain, a gain correction, matched filter with replica shaping, an attribute calculation for instantaneous amplitude and time variable gain.Additional information regarding this dataset is contained in the GSM data acquisition and processing report. Additional data products may be available on request