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

本记录描述的是“调查者号”（RV Investigator）IN2018_V05航次采集的海底剖面仪（sub bottom profiler）数据，该航次的研究主题为“塔斯马尼亚东南部固定曲流如何阻滞南极绕极流（Antarctic Circumpolar Current, ACC）？”，航次于2018年10月16日从霍巴特启航，2018年11月16日返回霍巴特。

本次航次的科学目标包括：(1) 布放EM-APEX剖面浮标群；(2) 在南极绕极流极锋（Polar Front）曲流的峰顶位置布放高型系泊锚系；(3) 对目标南极绕极流曲流的物理与生物地球化学特性开展全水深水文调查，并横穿极锋布设断面；(4) 沿极锋方向及横穿极锋开展Triaxus断面测量。

本数据集采用康斯伯（Kongsberg）SBP120型海底剖面仪采集，该设备可获取海底下方不同沉积物界面的镜面反射信号，其角分辨率为3°×3°。

该回声测深仪的扫频范围为2.5~7 kHz。SBP120在霍巴特往返航次的全程均进行了数据记录，但在南极绕极流航段内开展敏感的VMP布放作业期间，根据科考团队要求将设备设置为被动模式，进入声学静默状态。

本数据集存储于澳大利亚联邦科学与工业研究组织（Commonwealth Scientific and Industrial Research Organisation, CSIRO），格式包括*.raw原始格式（297个文件，总容量5.67 GB）与*.seg SEG-Y格式（292个文件，总容量5.65 GB）。

SEG-Y格式数据已应用实时处理流程，该流程包含增益调整、增益校正、带波形整形的匹配滤波、瞬时振幅属性计算以及时变增益处理。

有关本数据集的更多细节可查阅GSM数据采集与处理报告。额外的数据产品可根据申请提供。