RV Investigator Voyage IN2017_V01 CTD Data

This record describes the Conductivity-Temperature-Depth (CTD) data collected from the Marine National Facility RV Investigator voyage IN2017_V01 titled: "Interactions of the Totten Glacier with the Southern Ocean through multiple glacial cycles." The voyage took place from Hobart (TAS) to Hobart between the 14th January and 5th March, 2017.\n \nData for 33 deployments were acquired during this voyage using a Seabird SBE911 CTD, fitted with 36 twelve litre bottles on the rosette sampler. Casts 1-10, 13 – 33 were acquired using the Seabird SBE911 CTD unit 20, and casts 11 and 12 were acquired using the Seabird SBE911 CTD unit 22. CTD and sensors were changed in efforts to remediate sensor issues. CSIRO -supplied calibration factors were used to compute the pressures, and preliminary temperature and conductivity values. The data were subjected to automated QC to remove spikes and out-of-range values.\n\nProcessing was completed using CapPro processing software, version 2.9.\n\nFor the duration of the voyage significant spikes were observed across all recorded sensor channels. Investigation strongly suggests electrical interference was the cause of the data spikes, as mitigation measures have alleviated the issue. Care was taken in post processing to remove the spikes while maintaining true data features. The nature of the spiking was primarily extreme values persisting for a single scan, which were suitably detected and flagged by evaluating the second-difference of the data. An additional filter was also applied to the data which evaluated the median and standard deviation of the conductivity over a moving window, which was used to detect extreme changes in the sensor values characteristic of the noise induced spikes.\n\nThe final conductivity calibration was based on two deployment groupings, due to sensor changes during the voyage. The final calibration for casts 1-13 from the secondary sensor had a standard deviation (S.D) of 0.0010393 PSU, within our target of ‘better than 0.002 PSU’. The final calibration for casts 14-33 from the secondary sensor had a standard deviation (S.D) of 0.0020084 PSU. The standard product of 1dbar binned averaged were produced using data from the secondary sensors.\n\nThe final Oxygen calibration from the primary sensor had a S.D of 0.85991 uM. The agreement between the sensor and bottle data was good. Both Oxygen sensors calibrated closely.\nThe Biospherical photosynthetically active radiation (PAR), Wetlabs Transmissometer, the Wetlabs ECO chlorophyll, and O&A IMU sensors were also installed on the auxiliary A/D channels of the CTD.\n\nThe collected data were subsequently processed and archived within the CSIRO Oceans and Atmosphere (O&A) Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset may be contained in the Voyage Summary and the CTD Data Processing Report.\nLineage: Original field data.\nData processing and quality control by the Marine National Facility Data Acquisition and Processing Group (DAP). \nData processed and archived on 11/04/2018. Data were processed using the new CapPro system.\nFor this voyage a moving window filter was applied to remove noise spikes from the Pressure, conductivity and oxygen sensor values.本记录描述了从澳大利亚海洋国家设施（Marine National Facility）“调查者号”（RV Investigator）科考航次IN2017_V01中获取的温盐深（Conductivity-Temperature-Depth, CTD）仪数据，该航次主题为“托滕冰川与南大洋在多个冰期循环中的相互作用”。本次航次于2017年1月14日至3月5日期间开展，往返于霍巴特（塔斯马尼亚州，TAS）。 本次航次共完成33次CTD布放，采用搭载36个12升采水瓶的采水器架（rosette sampler），通过SeaBird SBE911型温盐深仪采集数据。其中，测站1-10、13-33的数据由SeaBird SBE911 CTD单元20采集，测站11、12的数据由SeaBird SBE911 CTD单元22采集。为修复传感器故障，期间更换了CTD及相关传感器。本次数据的压力、初步温度与电导率值均采用澳大利亚联邦科学与工业研究组织（CSIRO）提供的校准因子计算得到，并通过自动化质量控制（QC）剔除尖峰与超限值。 数据处理采用CapPro处理软件V2.9版本完成。 航次期间，所有记录的传感器通道均出现显著尖峰噪声。经排查，该问题由电气干扰引发，后续采取的缓解措施已有效改善该问题。后处理过程中，在保留真实数据特征的前提下，对尖峰噪声进行了剔除：该类尖峰主要表现为持续单个扫描周期的极端值，通过计算数据的二阶差分即可实现有效检测与标记；此外，还针对数据施加了额外滤波，通过对移动窗口内电导率的中位数与标准差进行评估，识别由噪声尖峰引发的传感器值极端变化。 由于航次期间更换了传感器，最终的电导率校准基于两组布放数据进行。针对次级传感器采集的测站1-13数据，最终校准的标准差（S.D）为0.0010393 实用盐度单位（PSU），优于预设目标“0.002 PSU以内”；针对次级传感器采集的测站14-33数据，最终校准的标准差为0.0020084 PSU。采用次级传感器数据生成了1分巴（dbar）分箱平均的标准产品。 来自主传感器的最终溶解氧校准标准差为0.85991 μM。传感器与采水瓶实测数据的吻合度良好，两台溶解氧传感器的校准结果均较为接近。 采水器架的辅助模数转换（A/D）通道还搭载了以下传感器：Biospherical公司生产的光合有效辐射（Photosynthetically Active Radiation, PAR）传感器、Wetlabs透射率仪、Wetlabs ECO叶绿素传感器以及O&A惯性测量单元（IMU）。 所采集的数据随后由澳大利亚联邦科学与工业研究组织海洋与大气（Oceans and Atmosphere, O&A）信息与数据中心（Information and Data Centre, IDC，位于霍巴特）完成处理与归档。关于本数据集的更多信息可参阅《航次总结》与《CTD数据处理报告》。 数据谱系：原始野外实测数据。 数据处理与质量控制由海洋国家设施数据获取与处理组（Data Acquisition and Processing Group, DAP）完成。 数据于2018年4月11日完成处理与归档，本次处理采用新版CapPro系统。 针对本次航次，还施加了移动窗口滤波，以剔除压力、电导率与溶解氧传感器数据中的噪声尖峰。