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.

本数据集包含大堡礁哈迪礁（Hardy Reef）上Fantasea浮动码头附属气象站的气象与海水温度数据，所采集的数据用于支撑澳大利亚海洋科学研究所（AIMS）的科研工作。数据可应其他研究者请求向其开放，亦面向公众公开。该气象站采用AIMS Mk3系统，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、气压、气温、光合有效辐射（PAR, Photosynthetically Active Radiation）、真风向（矢量平均）、真风速（30分钟平均）。

该气象站曾在哈迪礁的三个不同位置部署：
位置1：坐标-19.7340, 149.1808，部署时间为1989年6月至1993年11月；
位置2：坐标-19.7358, 149.1808，部署时间为1993年11月至1996年1月；
位置3：坐标-19.733, 149.167，部署时间为1996年1月至今。

1. 运行与气象传感器
气象站每半小时采集并存储数据至电子内存。中央基站通过高频（HF, High Frequency）无线电或电话线定期轮询各远端站，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。基站采用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，该机制仍可恢复绝大多数有效数据。远端站可本地存储数据达21天，系统集成了自动运行、远程控制、远程时间设置、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）为单位测量光照，其光谱响应经过定义与加权校准。过滤器老化导致的漂移是已知问题，但同类传感器均存在该缺陷。
- 温度传感器均采用Omega公司的可互换热敏电阻，该类传感器互换性强、精度较高，但可靠性存在短板，目前团队正考虑替换方案。
- 早期气象站的气压传感器为改装型Aanderaa传感器，Mk2站搭载Weathertronics单元，当前所有站点均为Mk3站，搭载互换性与精度更优的Vaisala气压计。

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、随时间的漂移误差、0~40℃环境温度范围带来的影响。以下为Mk3站所用传感器的规格参数。Mk5站将采用全新的传感器套件，部分基于Vaisala WXT510气象传感器。

气温与风速传感器具备互换性，无需单独校准，但部分传感器已通过国家标准设备进行过校验：
- 气温：可互换热敏电阻与电子组件的误差范围为±0.4℃，空气中的稳定时间为30秒；低风速条件下，温度屏蔽罩的抽吸效应会带来额外误差。
- 水温：可互换热敏电阻与电子组件的误差范围为±0.4℃，水中的稳定时间为30分钟；通常会采用更高精度的现场校准（误差约±0.1℃），该校准可溯源至0.04℃的标准基准。
- 太阳辐射（PAR）：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：误差为读数的2% ± 0.1%满量程偏差（FSD, Full Scale Deviation）。
- 风向：误差为读数的2% ± 0.1%满量程偏差（FSD, Full Scale Deviation）。

太阳辐射与风速参数的电气稳定时间为7秒，用于满足抗混叠滤波器的要求。Mk1与Mk2站在记录数据前，会对16秒内的16个采样点取平均；而Mk3站采用持续平均的软件系统。风速读数采用矢量平均算法，可正确处理风向信息。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站所用风速传感器的补充规格，Mk5站将采用新型传感器。传感器标称安装高度为距水面10米，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%响应恢复的距离常数为2.7 m。
- 风向：量程360°，正北方向电气开路误差为5°；阻尼比0.25；50%响应恢复的延迟距离为1.5 m；启动阈值1.0 m/s @ 10°；位移灵敏度1.5 m/s @ 5°位移；阻尼长度7.4 m；无阻尼长度7.2 m。

4. 水下温度传感器
Mk3站的水下温度传感器为可互换热敏电阻，可通过两线连接方式与气象站实现远距离部署。基础精度源于可互换单元的特性，但通过现场使用精密参考传感器进行校准可获得更高精度，该参考传感器本身可溯源至0.04℃的标准基准。