RV Investigator Voyage IN2017_V05 SBP120 Sub-bottom Profiler Data

This record describes sub bottom profiler data collected on RV Investigator voyage IN2017_V05, 'Long-term recovery of trawled marine communities 25 years after the world's largest adaptive management experiment', which departed Broome on the 11 October 2017 and returned to Henderson on the 10 November 2017.

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 continuously for the extent of the voyage.

Data are stored in *.raw 998 files 130 GB raw and *.segy 998 files 130 GB segy formats at CSIRO.

The segy format data had a real time processing stream applied, which applies a seabed mute, a bandpass or matched filter dependent on pulse type, and a time variable gain.

All *segy files were processed using Seismic Unix. The segy files are converted to *.su format, projected using suutm, trace shifted using sushift and the source coordinates copied to the group coordinates. The su data are written back to segy with utm zone number stored in byte 21 and group coordinates in byte locations 81 and 85.

Additional information regarding this dataset is contained in the GSM data acquisition and processing report. Additional data products may be available on request