RAN CTD Profile Data - HMAS LEEUWIN ProjectID: HI461LEE_H From: 2009-05-10 To: 2009-05-11

This dataset contains quality controlled vertical profiles of pressure, temperature and salinity measured by a Conductivity, Temperature and Depth (CTD) probe. The dataset contains 3 CTD profiles (casts) obtained during RAN Hydrographic Survey cruise HI461LEE_H from HMAS LEEUWIN. The CTD was manufactured by Falmouth Scientific and is the "2-inch Micro CTD" model. This CTD type is referred to operationally as the HS_CTD. This CTD is fitted within an inductive type conductivity cell, a platinum thermometer and silicon pressure sensor.The CTD temperature sensor is calibrated on the ITS-90 temperature scale against a master CTD using a controlled temperature bath. The pressure sensor is calibrated using a Druck Pressure Calibrator. The conductivity sensor is calibrated in a temperature controlled bath against seawater samples of known conductivity.The HS_CTD is lowered and raised by a hand winch sampling at a rate of 1.83 Hz. Data files were recorded in the downcast and upcast direction but most data is from downcasts due to higher quality. Raw CTD pressure data is not always monotonic due to transient up/down motion of winch/ship. Raw pressure data is subsetted to give a monotonic (increasing) sequence and then linearly interpolated to 1 decibar pressure intervals and converted to netCDF format files. Data is then flagged with quality control flags after visual inspection and comparison to average climatology and historical CTD casts.

本数据集包含经质量控制的压力、温度与盐度垂直剖面数据，此类数据由电导率-温度-深度（Conductivity, Temperature and Depth, CTD）探针采集获取。本数据集包含3次CTD施放剖面，采集自澳大利亚皇家海军（RAN）水文调查航次HI461LEE_H期间，搭载于HMAS LEEUWIN号。该CTD由Falmouth Scientific公司制造，型号为“2英寸微型CTD”，作业中该型号被称为HS_CTD。该CTD搭载感应式电导率池、铂温度计以及硅压式压力传感器。CTD的温度传感器依据ITS-90温标，通过控温水槽与标准CTD比对校准；压力传感器采用德鲁克（Druck）压力校准仪进行校准；电导率传感器则在控温水槽中，利用已知电导率的海水样本完成校准。HS_CTD通过手动绞车完成下放与回收，采样频率为1.83赫兹。数据文件在下沉剖面与上浮剖面过程中均有记录，但由于下沉剖面数据质量更高，多数有效数据来自下沉剖面。原始CTD压力数据因绞车与船舶的瞬态升降运动，并非始终呈单调递增序列。随后对原始压力数据进行子集化处理，得到单调递增序列，再以1分巴为间隔进行线性插值，并转换为netCDF格式文件。完成上述处理后，通过目视检查、与平均气候态数据及历史CTD施放剖面的比对，为数据添加质量控制标记。