RAN CTD Profile Data - HMAS LEEUWIN ProjectID: HI460(A)LEE_H From: 2009-09-03 To: 2009-09-10

This dataset contains quality controlled vertical profiles of pressure, temperature and salinity measured by a Conductivity, Temperature and Depth (CTD) probe. The dataset contains 11 CTD profiles (casts) obtained during RAN Hydrographic Survey cruise HI460(A)LEE_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，由电导-温度-深度（Conductivity, Temperature and Depth, CTD）探针采集获取。本数据集包含11组CTD剖面（测次）数据，采集自澳大利亚皇家海军（RAN）水文勘测航次HI460(A)LEE_H，搭载平台为HMAS LEEUWIN号舰艇。

该CTD探针由福尔茅斯科学公司（Falmouth Scientific）制造，型号为“2英寸微型CTD”，在作业中被称为HS_CTD。该型CTD搭载感应式电导池、铂电阻温度计与硅压敏传感器。

CTD温度传感器依据ITS-90国际温标，通过控温浴槽与标准CTD进行校准；压力传感器采用德鲁克压力校准仪（Druck Pressure Calibrator）完成校准；电导率传感器则在控温浴槽中，使用已知电导率的海水样本完成标定。

HS_CTD通过手动绞车收放，采样频率为1.83赫兹。数据文件在下沉剖面与上浮剖面作业过程中均有记录，但由于下沉剖面的数据质量更优，绝大多数有效数据来自下沉剖面。原始CTD压力数据会因绞车与船舶的瞬态升降运动，无法始终保持单调变化特征。对此，原始压力数据将被筛选为单调递增序列，随后以1分巴为压力间隔进行线性插值，并转换为netCDF格式文件。最终，经目视检查、与平均气候态数据及历史CTD剖面比对后，为所有数据添加质量控制标记。