IN2023_V04 Southern Ocean Bathymetry 10m - 210m Multi-resolution AusSeabed products

This layer group describes multibeam echosounder data collected on RV Investigator voyage IN2023_V04 titled "International nutrient inter-comparison study in the Southern Ocean: quantifying and identifying the causes of differences in dissolved inorganic nutrient datasets between global seagoing laboratories - Phase 2". The voyage took place between June 5 and June 19, 2023, departing from Hobart (TAS) and arriving in Hobart (TAS).\n\nThe purpose of this voyage was to conduct INIV 2023 phase 2 of the international inter-comparison voyage previously conducted by CSIRO in 2017.\n\nThis dataset is published with the permission of CSIRO. Not to be used for navigational purposes.\n\nThe dataset contains bathymetry grids of 10m to 210m resolution of the Southern Ocean produced from the processed EM122 and EM710 bathymetry data.\nLineage: Multibeam data was logged from the EM’s in Kongsberg’s proprietary *.all format and was converted to be processed within CARIS HIPS and SIPS version 11.4.18. Data were imported into the HIPS project using EM Height and the vessel file appropriate for either the EM122 or EM710. GPS tide was computed using the EGM2008 model EGM_2008_1Min_Aust_WGS84.csar. TPU values were computed using Measured Sound Velocity = 0.5 and Surface Sound Velocity = 0.2. The raw files were analysed for noise and cleaned manually. The data was then gridded at the highest resolution possible and further inspected for outliers.\n\nThe data was then gridded at multiple resolutions in python Caris batch script using a Depth filter Vs Resolution guideline derived from AusSeabed Multibeam guidelines v2 and further inspected for outliers. Final raster products are available in L3 folder of this collection. Final processed data were also exported per line as GSF and ASCII format and available in the L2 folder of this collection.

本图层组描述了“调查者号”（RV Investigator）科考航次IN2023_V04所采集的多波束测深仪（multibeam echosounder）数据，该航次的研究课题为《南大洋国际营养盐比对研究：量化并识别全球远洋实验室间溶解无机营养盐数据集差异的成因——第二阶段》。本次航次于2023年6月5日至6月19日开展，从塔斯马尼亚州霍巴特港启航并最终返回霍巴特港。

本次航次的核心任务是执行澳大利亚联邦科学与工业研究组织（CSIRO）于2017年首次开展的国际营养盐比对航次的INIV 2023第二阶段工作。

本数据集经CSIRO许可发布，严禁用于导航用途。

本数据集包含基于经过处理的EM122与EM710多波束测深数据生成的南大洋水深栅格，分辨率覆盖10米至210米区间。
数据溯源：多波束原始数据以Kongsberg专有*.all格式从EM系列声呐中记录，随后在CARIS HIPS and SIPS 11.4.18版本中完成处理。通过EM Height工具及适配EM122或EM710的船舶配置文件，将数据导入HIPS项目。采用EGM2008模型（EGM_2008_1Min_Aust_WGS84.csar）计算GPS潮位。总传播不确定度（TPU）值通过以下参数计算：实测声速取0.5，表层声速取0.2。对原始数据文件进行噪声分析并完成手动清噪。随后以最高可行分辨率进行栅格化处理，并对异常值进行全面排查。

随后，基于澳大利亚海底多波束指南v2（AusSeabed Multibeam guidelines v2）中推导的“水深滤波-分辨率”准则，通过Python脚本调用CARIS批处理工具，以多种分辨率对数据进行二次栅格化，并再次排查异常值。本数据集集合的L3文件夹中提供最终栅格产品。此外，已按测线将最终处理完成的数据导出为GSF与ASCII格式，存放于本集合的L2文件夹中。