Hardy Reef Automated Marine Weather And Oceanographic Station

This dataset contains meteorological and sea temperature data from the weather station attached to the Fantasea pontoon on Hardy Reef 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 an AIMS Mk3 SystemData recorded: Sea Temperature (2.5m and 9m at MSL), Barometric Pressure, Air Temperature, Solar Radiation (PAR), Wind Direction True (vector averaged), Wind Speed True (30 min average).This weather station has been deployed in three different locations on Hardy Reef.Location 1: -19.7340, 149.1808 from June 1989 to November 1993Location 2: -19.7358, 149.1808 from November 1993 to January 1996Location 3: -19.733, 149.167 from January 1996 to present.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.本数据集收录了大堡礁哈迪礁（Hardy Reef）上“梦幻海（Fantasea）浮筒”附属气象站的气象与海水温度数据，其采集目的为支撑澳大利亚海洋科学研究所（AIMS）的相关科研工作。该数据集可应其他研究人员请求及面向公众公开获取。 该气象站为AIMS Mk3系统，所记录的数据包括：平均海平面（MSL，Mean Sea Level）下2.5米与9米处的海水温度、大气压力、空气温度、光合有效辐射（PAR，Photosynthetically Active Radiation）、真风向（矢量平均法）以及真风速（30分钟平均值）。 该气象站曾在哈迪礁的三个不同点位部署： 点位1：坐标-19.7340, 149.1808，部署时段为1989年6月至1993年11月 点位2：坐标-19.7358, 149.1808，部署时段为1993年11月至1996年1月 点位3：坐标-19.733, 149.167，部署时段为1996年1月至今 1. 系统运行与气象传感器 该气象站每半小时采集并存储一次数据至电子存储器。中央基站通过高频无线电（HF radio）或电话线定期呼叫各远端站点，数据以频移键控信号形式通过无线电传输，并封装为信息数据包。系统采用奇偶校验与校验和方法检测传输错误，基站可识别无效数据包并请求重传，即便通信条件不佳，该机制仍可恢复绝大多数有效数据。远端站点可本地存储数据长达21天。系统集成了自动运行、远程控制、远程校时、内置诊断等功能模块。 传感器是气象站的核心组成部分，以下传感器的选型均综合考量了成本、可靠性与精度： * 风速风向传感器由R.M.Young公司制造，型号为05103，采用螺旋桨式设计，具备高线性度、高互换性与低启动阈值特性，所测风向为风的来向。 * 太阳辐射传感器为Licor公司生产的水下量子传感器，用于测量光合有效辐射（PAR），其光谱响应已完成定义与加权校准。该传感器的滤波片老化导致的漂移问题已被证实存在，但同类产品均存在类似问题。 * 温度传感器均采用Omega公司的可互换热敏电阻，这类传感器具备互换性与高精度优势，但可靠性表现欠佳，目前团队正在考虑替换方案。 * 早期气象站搭载的是经过改装的Aanderaa型气压传感器，Mk2站配备Weathertronics单元，当前所有站点均为Mk3系统，搭载互换性与精度更优的Vaisala气压传感器。 2. 系统精度 系统精度由以下各项误差之和计算得出：校准误差、传感器互换误差、随时间产生的漂移误差，以及环境温度范围0~40℃带来的影响。 以下为Mk3站搭载传感器的技术规格。Mk5站将采用全新的传感器套件，部分基于Vaisala WXT510气象传感器开发。 温度与风速传感器均具备互换性，无需单独校准，但部分传感器已通过标准设备进行过精度校验： * 空气温度：采用可互换热敏电阻与电子组件，测量误差为±0.4℃，在空气中的稳定时间为30秒。当风速较低时，温度屏的抽吸效应会带来额外误差。 * 水温：采用可互换热敏电阻与电子组件，测量误差为±0.4℃，在水中的稳定时间为30分钟。实际应用中通常采用现场原位校准以获得更高精度（约±0.1℃），该校准可溯源至0.04℃精度的标准参考物。 * 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%。 * 大气压力：测量误差为±1百帕。 * 风速：误差为读数的2% ±0.1%满量程（FSD，Full Scale Deflection）。 * 风向：误差为读数的2% ±0.1%满量程（FSD，Full Scale Deflection）。 太阳辐射与风速参数的电稳定时间为7秒，这是抗混叠滤波器的必要设置。Mk1与Mk2站在数据记录前会对16秒内的16个采样点取平均，而Mk3站采用连续平均的软件系统。风速读数采用矢量平均法，可正确反映风向信息。 校准流程与相关规程详见工程官网。 3. 风速传感器技术规格 以下为Mk3站搭载风速传感器的补充技术规格。Mk5站将采用全新的风速传感器。传感器安装位置距水面标称高度为10米。R.M.Young公司的该款传感器特性如下： * 风速：量程0~60 m/s；螺距：每转气流通过距离29.4 cm；距离常数：63%响应恢复距离为2.7 m。 * 风向：量程360°，正北方向电气开路偏差为5°；阻尼比：0.25；延迟距离：50%响应恢复距离为1.5 m；启动阈值：1.0 m/s @ 10°位移；位移响应：1.5 m/s @ 5°位移；阻尼段长度：7.4 m；无阻尼段长度：7.2 m。 4. 水下温度传感器 Mk3站的水下温度传感器采用可互换热敏电阻，可通过二线制连接方式安装在距气象站较远的位置。其基础精度来自可互换组件的特性，但通过现场原位使用精密参考传感器进行校准，可获得更高精度。这类参考传感器本身可溯源至0.04℃精度的标准校准物。