RV Investigator Voyage IN2021_V02 EM122 Multibeam Echosounder Data

This record describes multibeam echosounder data collected on RV Investigator voyage IN2021_V02 (SOTS: Southern Ocean Time Series automated moorings for climate and carbon cycle studies southwest of Tasmania), which departed Hobart on the 14th April 2021 and returned to Hobart on the 28th April 2021.The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter during the voyage.The EM122 provides a 1 degree by 1 degree angular resolution. The echosounder's nominal frequency is 12 kHz.Data are stored in *.all raw format for bathymetry and backscatter and *.wcd format for watercolumn backscatter at CSIRO. There are 191 files totalling 11.4 GB of raw bathymetry & backscatter data, and 192 files totalling 14.7 GB of raw watercolumn data in this dataset.Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.all format are corrected for motion and position.The data have been reduced to approximate Mean Sea Level (MSL) using the Earth Gravitation Model 2008 (EGM2008) 1 arc-minute grid. Tide corrections were not applied to the processed data. Processed data had outliers removed. Processed line data are available in *.gsf and ascii format, and processed bathymetry and backscatter grids in geotiff format.Additional information regarding this dataset, including information on processing streams, is contained in the GSM data acquisition and processing report. Additional data products may be available on request.

本数据集记录了探索者号科考船（RV Investigator）航次IN2021_V02期间采集的多波束测深声呐（multibeam echosounder）数据，该航次旨在开展塔斯马尼亚西南部海域气候与碳循环研究的南大洋时间序列自动锚泊系统（Southern Ocean Time Series automated moorings for climate and carbon cycle studies southwest of Tasmania，简称SOTS）科考任务，航次于2021年4月14日从霍巴特启航，同年4月28日返回霍巴特港。本航次采用康士伯（Kongsberg）EM122型多波束测深声呐，采集了海底测深数据、反向散射信息以及水柱反向散射数据。该声呐的角分辨率为1°×1°，标称工作频率为12 kHz。本数据集的水深与反向散射原始数据采用*.all格式存储，水柱反向散射原始数据采用*.wcd格式存储，均存放于澳大利亚联邦科学与工业研究组织（Commonwealth Scientific and Industrial Research Organisation，简称CSIRO）。本数据集包含191个原始水深与反向散射数据文件，总容量达11.4 GB；另有192个原始水柱数据文件，总容量达14.7 GB。数据采集阶段已针对该数据应用声速剖面校正；*.all格式存储的水深数据已完成运动校正与位置校正。本数据集已采用地球重力模型2008（Earth Gravitation Model 2008，简称EGM2008）1角分网格数据，将所有数据归算至近似平均海平面（Mean Sea Level，简称MSL）；但处理后的数据未施加潮汐校正。已对处理后的数据剔除异常值。处理后的测线数据可通过*.gsf格式与ASCII格式获取，处理后的水深与反向散射网格数据可通过GeoTIFF格式获取。有关本数据集的更多信息（包括处理流程相关内容）均收录于《GSM数据采集与处理报告》中。额外的数据产品可根据申请获取。