RV Investigator Voyage IN2018_V04 EM122 Multibeam Echosounder Data

This record describes multibeam echosounder data collected on RV Investigator voyage IN2018_V04, 'Constraining external iron inputs and cycling in the southern extension of the East Australian Current' which departed Hobart on the 11 September 2018 and returned to HObart on the 8 October 2018.The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter.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 574 files totalling 51.5 GB of raw 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.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.

本记录描述了“探索者号”（RV Investigator）科考船IN2018_V04航次采集的多波束测深声呐数据，该航次主题为“约束东澳大利亚洋流南部延伸区的外部铁输入与循环过程”，于2018年9月11日从霍巴特起航，同年10月8日返回霍巴特。本次任务采用康士伯（Kongsberg）EM122型多波束测深声呐，采集了海底地形测深、反向散射信息以及水体柱反向散射数据。该EM122声呐的角分辨率为1°×1°，标称工作频率为12 kHz。相关原始数据中，测深与反向散射数据以*.all格式存储，水体柱反向散射数据则以*.wcd格式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）。本数据集共计包含574个文件，总原始数据量达51.5 GB。数据采集阶段已对其施加声速剖面校正；*.all格式存储的测深数据已完成运动与位置校正，但未施加潮汐校正，且处理后的数据已完成异常值剔除。经处理的测线数据可通过*.gsf格式与ASCII格式获取，经处理的测深与反向散射网格数据则以GeoTIFF格式提供。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，额外的数据产品可按需申请获取。