Ningaloo (Milyering) Automated Marine Weather And Oceanographic Station

This dataset contains meteorological data from the weather station located at the CALM Milyering Visitor Centre in Western Australia. 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: Barometric Pressure, Air Temperature, Solar Radiation (PAR), Wind Direction True (vector averaged), Wind Speed True (30 min average).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.* 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 m本数据集包含位于西澳大利亚州CALM米林德里游客中心（CALM Milyering Visitor Centre）的气象站所采集的气象数据。这些数据的采集旨在支持澳大利亚海洋科学研究所（Australian Institute of Marine Science, AIMS）的科学研究工作。数据可应其他研究人员与公众的申请对外公开。该气象站为AIMS Mk3系统，记录的参数包括：气压、气温、太阳辐射（光合有效辐射（"Photosynthetically Active Radiation", PAR））、真风向（矢量平均）、真风速（30分钟平均）。 1. 运行机制与气象传感器 气象站每半小时采集并将数据存储至电子存储器中。中央基站通过高频无线电（HF radio）或电话线定期轮询各远程气象站。数据以频移键控信号形式通过无线电传输，并被组织为信息数据包。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，该机制可在通信质量不佳的情况下恢复极高比例的有效数据。远程气象站可本地存储数据长达21天。系统已集成自动运行、远程控制、远程时间设置与内置诊断等功能。 传感器是气象站的核心组成部分，以下传感器的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公司生产，型号为05103。该传感器为螺旋桨式，具备高线性度、高互换性与低启动阈值的优势，风向测量结果为风的来向。 - 太阳辐射传感器为Licor公司生产的水下量子传感器，以光合有效辐射（"Photosynthetically Active Radiation", PAR）为指标测量光照。其光谱响应经过定义与加权处理，过滤器老化导致的零点漂移已被证实为一类问题，该问题同样存在于同类设备中。 - 气温传感器均采用Omega公司的互换式热敏电阻，此类传感器具备互换性与高精度的特点，但可靠性存在问题，目前我方正在考虑替代方案。 - 早期气象站的气压传感器为经过改装的Aanderaa型号，Mk2型气象站搭载Weathertronics单元。目前所有气象站均为Mk3系统，搭载互换性与精度更优的Vaisala气压计。 2. 系统精度 系统精度由以下几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，以及环境温度在0~40℃区间内产生的影响误差。 以下为Mk3型气象站所使用传感器的技术规格。Mk5型气象站将采用全新的传感器套件，其部分选型基于Vaisala WXT510气象传感器。 气温与风速传感器均具备互换性，且无需单独校准，但部分传感器已通过标准仪器进行过校验。 - 气温：采用互换式热敏电阻与电子元件的测温系统误差范围为±0.4℃，在空气中的响应稳定时间为30秒。当风速较低时，气温防护屏的抽吸效应会引入额外误差。 - 太阳辐射（PAR）：测量值误差为±5%，传感器初始年漂移量约为-4%。 - 气压：误差范围为±1百帕。 - 风速：误差为测量值的2% ±0.1%满量程（"Full Scale Deflection", FSD）。 - 风向：误差为测量值的2% ±0.1%满量程（"Full Scale Deflection", FSD）。 太阳辐射与风速参数的电信号稳定时间为7秒，该参数是抗混叠滤波器的必要设计要求。Mk1与Mk2型气象站在数据记录前，会在16秒内对16组采样值取平均；Mk3型气象站则采用持续平均的软件系统。由于风速读数采用矢量平均方式，因此风向的计算结果更为准确。 校准流程与操作规范已在工程官网上详细说明。 3. 风速传感器技术规格 以下为Mk3型气象站所使用风速传感器的补充技术规格。Mk5型气象站将采用全新的风速传感器。风速传感器的标称安装高度为水面以上10米。R.M.Young公司生产的该款传感器具备以下特性： - 风速：量程0~60 m/s；螺距：每旋转一圈气流通过距离为29.4 cm；距离常数：63%响应恢复距离为2.7 m。 - 风向：量程360°，正北方向存在5°的电气间隙；阻尼比：0.25；延迟距离：50%响应恢复距离为1.5 m；启动阈值：10°方位下的启动风速为1.0 m/s；位移特性：5°位移对应的输出为1.5 m/s；阻尼固有长度：7.4 m；无阻尼固有长度：7.2 m。