Orpheus Island Automated Marine Weather And Oceanographic Station

This dataset contains meteorological and sea temperature data from the weather station located on Orpheus Island on the Great Barrier Reef. These data are collected to support scientific research at AIMS. Data are made available on request to other researchers and to the public. The weather station is a Campbell Scientific Australia System.Data recorded: Sea Temperature (1.9m and 6m at MSL), Air Temperature, Solar Radiation (PAR), Wind Direction True (scalar averaged), Wind Speed True (10 min average prior to every half hour and maximum wind gust), Rainfall.Wind speeds shown are NOT indicative of wind speeds generally in this area. This is because the Orpheus AWS is situated on the lee side of Orpheus island and is protected from SE winds.1. Operation and Weather SensorsThe weather stations collect and store data in electronic memory every half-hour. A central base station calls each remote station regularly using HF radio or telephone lines. The data is transmitted over the radio as a frequency shift keyed signal, organised as packets of information. Errors are detected using parity and check sum methods. Invalid packets are identified by the Base Station, which requests they be sent again. This concept allows recovery of a very high percentage of the data despite poor communications. Remote stations store data for 21 days. Features such as automatic operation, remote control, remote time setting, built in diagnostics, have been developed and incorporated.The sensors are a key part of a weather station. The following are chosen considering the cost, reliability and accuracy.* R.M.Young manufactures the wind sensor, a model number 05103. It is a propeller type with the advantages of being highly linear, highly interchangeable and having a low threshold. Wind direction is measured as the direction the wind is coming from.* The solar radiation sensor is an Under Water Quantum Sensor made by Licor. It measures light in terms of its "Photosynthetically Active Radiation" (PAR). The spectral response is defined and weighted. Drift due to aging of the filters has proven to be a problem, but this applies to similar units too.* Temperature sensors are all Omega Interchangeable Thermistors. These are interchangeable and have high accuracy, but reliability has proven a problem. We are considering alternatives.* The barometric sensor was a modified Aanderaa type on earlier stations. The Mk2 stations were fitted with a Weathertronics Unit. Now all stations are Mk3 stations fitted with a Vaisala barometer which is more interchangeable and more accurate.2. System AccuracySystem accuracy is calculated as the sum of errors caused by: * Calibration * Interchanging sensors * Drift with time * Effects of an ambient temperature range from 0-40 degrees C.The following are the specifications of the sensors used with Mk3 stations. A new sensor suite will be used with Mk5 stations, partly based on the Vaisala WXT510 weather sensor.Both the temperature and wind sensors are interchangeable, and not individually calibrated, though some individual sensors have been checked against standards.* Air Temperature: Interchangeable thermistor and electronics is within +/- 0.4 deg. C, with a 30 seconds settling time in air. There are additional errors due to the aspiration of the temperature screen at low wind speeds.* Water temperature: Interchangeable thermistor and electronics is within +/- 0.4 deg. C, with a 30 minutes settling time in water. A higher precision in situ calibration is normally used (around +/- 0.1 degrees), traceable to a 0.04 degrees standard.* Solar radiation (PAR): +/- 5% of reading. Sensor drift is approximately -4% per year initially.* Barometric pressure: +/- 1 hecto Pascal.* Wind speed: 2% of reading +/- 0.1% FSD.* Wind direction: 2% of reading +/- 0.1% FSD.Electrical settling time for solar radiation and wind parameters is 7 seconds. This is necessary for anti-aliasing filters. Mk1 and Mk2 stations averaged 16 samples over the 16 seconds before logging. Mk3 stations use a continuously averaging software system. The wind readings are vector averaged, so direction is accounted for properly.Calibration procedures and routines are detailed on the Engineering website.3. Wind Sensor SpecificationThe following are additional specifications of the wind sensors used with Mk3 stations. A new sensor will be used with Mk5 stations. Wind sensors are mounted at a nominal 10 meters above water. The R.M. Young sensor has the following characteristics:* Wind SpeedRange: 0-60 m/sPitch: 29.4 cm air passes per rev.Distance constant: 2.7 m for 63% recovery* Wind DirectionRange: 360 deg, with 5 deg electrically open at northDamping ratio: 0.25Delay distance: 1.5 m for 50% recoveryThreshold: 1.0 m/s @ 10 deg.Displacement: 1.5 m/s @ 5 deg. displacement Damped w/length: 7.4 mUndamped w/length: 7.2 m4. Underwater Temperature SensorsThese sensors are interchangeable thermistors in Mk3 stations. They can be mounted a significant distance from the weather station, using a 2 wire connection. The basic accuracy is due to the use of interchangeable units. However improved accuracy is obtained by calibrating against a precision reference sensor in situ. These are in turn calibrated against a standard traceable to 0.04 degrees.

本数据集包含取自大堡礁奥费斯岛（Orpheus Island）气象站的气象与海水温度数据，旨在为澳大利亚海洋科学研究所（AIMS）的科学研究提供支撑。该数据可应其他研究人员请求向公众公开。本气象站采用澳大利亚坎贝尔科学（Campbell Scientific Australia）系统。
本次记录的参数包括：平均海平面下1.9米与6米处的海水温度、气温、光合有效辐射（Photosynthetically Active Radiation，PAR）、真风向（标量平均值）、真风速（每半小时前10分钟平均值及最大阵风）、降雨量。
此处展示的风速并非该区域通用风速参考，因奥费斯岛自动气象站（AWS）位于奥费斯岛的背风侧，受东南风遮蔽。

1. 运行与气象传感器
气象站每半小时采集一次数据并存储至电子存储器。中央基站通过高频（High Frequency，HF）无线电或电话线定期轮询各远程站点。数据以频移键控信号形式通过无线电传输，封装为信息数据包。基站通过奇偶校验与校验和方法检测错误，识别无效数据包并请求重传，即便通信条件不佳也可恢复绝大多数数据。远程站点可存储数据长达21天。系统集成了自动运行、远程控制、远程授时、内置诊断等功能模块。

传感器是气象站的核心组成部分，选型综合考量了成本、可靠性与精度：
- 风速风向传感器由R.M.Young制造，型号为05103，为螺旋桨式传感器，具备高线性度、高互换性与低启动阈值特性。风向测量以风的来向为基准。
- 太阳辐射传感器为LICOR公司生产的水下量子传感器，以光合有效辐射（PAR）为单位量化光照，其光谱响应经过定义与加权。传感器滤镜老化导致的漂移问题已被证实存在，但同类产品均存在该问题。
- 温度传感器均为欧米茄（Omega）互换型热敏电阻，具备互换性与高精度，但可靠性存在短板，目前团队正在考虑替代方案。
- 早期气象站采用改装自Aanderaa的气压传感器，MK2型站点配备Weathertronics单元。目前所有站点均为MK3型，搭载维萨拉（Vaisala）气压传感器，该传感器互换性与精度更优。

2. 系统精度
系统精度由以下误差项之和计算得出：校准误差、传感器互换误差、随时间推移的漂移误差，以及0~40℃环境温度范围带来的影响。以下为MK3型站点搭载传感器的技术规格。MK5型站点将采用全新传感器套件，部分基于维萨拉WXT510气象传感器。
气温与风速传感器具备互换性，未进行单台校准，但部分传感器已对照国家标准进行过检测：
- 气温：采用互换型热敏电阻与电子元件，精度为±0.4℃，在空气中的稳定时间为30秒。低风速环境下，温度屏的抽吸作用会带来额外误差。
- 水温：互换型热敏电阻与电子元件精度为±0.4℃，在水中的稳定时间为30分钟。通常采用原位高精度校准（精度约±0.1℃），可溯源至0.04℃标准。
- 太阳辐射（PAR）：测量误差为读数的±5%。传感器初始年漂移约为-4%。
- 气压：±1百帕。
- 风速：测量误差为读数的2% ± 0.1%满量程偏差（Full Scale Deviation，FSD）。
- 风向：测量误差为读数的2% ± 0.1%满量程偏差（FSD）。
太阳辐射与风速参数的电稳定时间为7秒，用于抗混叠滤波。MK1与MK2型站点在记录前的16秒内对16个采样点取平均；MK3型站点采用持续平均软件系统。风速读数采用矢量平均，可正确核算风向。校准流程与规程详见工程官网。

3. 风速传感器规格
以下为MK3型站点搭载的风速传感器的额外规格。MK5型站点将采用全新传感器。风速传感器安装于距水面标称10米高度处。R.M.Young传感器的特性如下：
- 风速：量程0~60 m/s；每转气流通过距离：29.4 cm；63%响应恢复距离常数：2.7 m。
- 风向：量程360°，北向电气开路偏差为5°；阻尼比：0.25；50%响应恢复延迟距离：1.5 m；启动阈值：10°时为1.0 m/s；位移响应：位移5°时为1.5 m/s；阻尼波长：7.4 m；非阻尼波长：7.2 m。

4. 水下温度传感器
MK3型站点的水下温度传感器为互换型热敏电阻，可通过两线连接远离气象站安装。基础精度源于采用互换型元件，但通过原位对照精密参考传感器进行校准可获得更高精度，这些参考传感器均溯源至0.04℃标准。