PAR001 Optical disdrometer data at Cabauw

<strong>Description:</strong> In-situ measurements of raindrop size distributions, fall velocities, drop number concentrations and surface rain rates recorded by an OTT Parsivel2 disdrometer named "PAR001" at the remote sensing site in Cabauw. Note that "PAR001" is co-located with another identical disdrometer called "PAR002". This co-location can be used to cross-check data, perform quality control and/or assess measurement uncertainty due to sensor calibration, random sampling effects and environmental effects such as wind speed/direction which are known to substantially affect the accuracy of optical disdrometers.<br><strong>Format:</strong> Each NetCDF file covers a full month of observations. The temporal resolution is 1 minute. Data are provided "as is", without any post-processing. The NetCDF files contain all relevant information about all the variables, attributes and units. The global attributes of the NetCDF files contain important information about the type of sensor, logging software, project contributors and history of the dataset. If a monthly file is missing, no data are available for this month.<br><strong>Relevance:</strong> Optical disdrometer data are useful for studying the type, dynamics and microphysics of precipitation from the perspective of a fixed observer on the ground. The data can be used to help calibrate weather radars, improve quantitative precipitation estimates, calculate the absorption/attenuation/propagation of electromagnetic signals through the atmosphere, and quantify important physical quantities such as liquid water content, rain amount, intensity and kinetic energy.<br><strong>Notes: </strong>This dataset is updated approximately every 3 months. Please reach out to the authors if you need access to the most recent data.<br><strong>Known issues:</strong>Lots of data in 2021 were lost to connectivity issues. Notable periods are June 2-21, July 9 to August 11, September 6-15, September 20 to October 5.In 2023, a major update of the data logging system was implemented, which caused some loss of data between November 8 and December 22.

**描述：** 原位测量了部署于卡堡（Cabauw）遥感站点的OTT Parsivel2型激光雨滴谱仪（disdrometer）“PAR001”所采集的雨滴尺寸分布、雨滴下落速度、雨滴数浓度与地表降雨率数据。需注意，“PAR001”与另一台同款激光雨滴谱仪“PAR002”同址布设。该同址部署方案可用于开展数据交叉验证、质量控制，以及评估由传感器校准、随机采样效应，以及已知会显著影响光学雨滴谱仪精度的风速/风向等环境因素所导致的测量不确定度。
**数据格式：** 每份NetCDF文件涵盖一整月的观测数据，时间分辨率为1分钟。数据按“原样”提供，未经过任何后处理。NetCDF文件包含所有变量、属性与单位的相关信息，其全局属性中存储了传感器类型、数据记录软件、项目参与方及数据集历史等重要元数据。若某月份对应的NetCDF文件缺失，则表示该月无可用观测数据。
**数据适用性：** 光学雨滴谱仪数据可用于从地面固定观测视角研究降水的类型、动力学特征与微物理过程。该数据集可辅助气象雷达校准、提升定量降水估测精度、计算电磁信号在大气中的吸收/衰减/传播特性，以及量化液态水含量、降雨量、降雨强度与动能等重要物理量。
**备注：** 本数据集约每3个月更新一次。若需获取最新数据，请联系数据集作者。
**已知问题：** 2021年因通信连接故障丢失大量数据，具体缺失时段为6月2日至21日、7月9日至8月11日、9月6日至15日、9月20日至10月5日。2023年，数据记录系统完成重大升级，导致11月8日至12月22日期间出现部分数据丢失。