Disdrometer data of the Thies Laser Niederschlags Messer (LNM) since 2019 of about 150 German meteorological SYNOP stations

[Version comment] This is not the newest version! The newest version can be found here: https://doi.org/10.5281/zenodo.19265418 This is an updated version from 2026-03-05 of the data set that has been published on 2025-09-19. Station metadata file has been cleaned of a station which does not have an LNM. Corresponding SYNOP data of this station have been removed from the SYNOP data files. LNM data and additional SYNOP data from 2025 have been added. Minor fixes in the Documentation (format description of the LNM data telegrams) Introduction As part of its synoptic meteorological weather data measuring network (automated SYNOP network of ground stations), the German Meteorological Service continuously operates about 150 laser-optical disdrometers, the Laser Niederschlags Messer (LNM) from manufacturer Thies. This device registers the size and vertical fallspeed component of each particle (raindrops, graupel, snowflakes, hail, or anything else) that passes trough a horizontally oriented laser light sheet of length 22.8 cm, with 2.0 cm and height 0.75 mm. From all particles registered during 1 minute, a 2-dimensional discrete distribution (numbers in 20x22 fallspeed-diameter-classes) is constructed and several precipitation characterizing integral parameters are derived, such as precipitation rate, estimated type of precipitation according to WMO ww tables, estimated equivalent radar reflectivity factor, particle size distribution, etc. Relevant for the operational observations of DWD is only the estimated type of precipitation, which is part of the SYNOP reports. However, the 2-D fallspeed-diameter distributions for each minute ("raw data") are also recorded, but not put into DWD's official longterm data bases. Because these raw data may be highly relevant and interesting for the international scientific community in the fields of cloud physics, numerical weather prediction and radar meteorology, we provide via Zenodo a comparatively large raw data set for the years 2019 to 2025 of >= 150 stations throughout Germany. The data set is accompagnied by additional parameters which are relevant for quality control and cross checks, namely 10-minute values of temperature, relative humidity, accumulated precipitation from rain gauges, cloud cover, wind speed and wind direction. All relevant station meta data are provided as well. DWD operates two different software versions of the LNM depending on the SYNOP station, namely version 2 and 3. The two versions differ in the content of the data telegrams. Documentation Below we provide the most important informations about the data set. It is accompagnied by some PDF documents in the compressed tar archive Documentation.tgz : Technical manual specifically for the DWD devices of version 3 (in German language only): LNM_manual_Thies_deu_kurz.pdf (short manual) LNM_manual_Thies_deu.pdf (detailed manual) English translation/description of the data format and the diameter-velocity class limits for both device versions: LNM_telegram_engl_v2+v3.pdf LNM_classes.pdf English manual from the manufacturer website (see below) not specific for DWD and applicable to version 2 devices: 5.4110.xx.x00_laser_precipitation_monitor_eng_short.pdf (short manual) 5.4110.xx.x00_laser_precipitation_monitor_eng.pdf (detailed manual) README file Instrument description Short and detailed descriptions of the specific DWD-version of the LNM are given in German language, see above. English manuals are not available for the DWD-specific version, but have been downloaded from the manufacturer website for a newer instrument version and are also provided in Documentation.tgz. Links to the manufacturer's website can be found below. Data files and formats Disdrometer data Yearly gzipped tar archives named lnm_thies_DWD_20XX.tgz One data file per day and per station in it's own directory. Directory structure in each archive: ./<yyyy>/<mm>/<dd>/<wmoid>/<data-file> (yyyy=year, mm=month, dd=day, wmoid=5-digit WMO station ID) File name <V>_<wmoid>_<yyyy>-<mm>-<dd>.txt (V=1-digit instrument version, either "2" or "3"), e.g. 3_10474_2023-07-01.txt One line per one-minute measuring interval (nominally 1440 lines per daily file) Semicolon-separated format, many records per line Detailed documentation of each record in LNM_telegram_engl_v2+v3.pdf Definition of the diameter- and fall velocity classes in LNM_classes.pdf The time stamp in each line is the approximate end of the measuring minute in UTC. Due to technical issues with time synchronisation, there is an uncertainty of about 30 seconds. Therefore, we have rounded the time to the nearest full minute. Sometimes 1 to 5 minutes in a daily file are missing due to spurious data stream transmission problems which are not recoverable. Therefore not every file contains the full 1440 lines. Files from days where stations have only partly been operational have been removed, e.g., when a certain station has been shut down or installed during that day, or when there was a power-outage or other disruption of the station operations. Additional synoptic data Yearly gzipped tar archives named synop10min_DWD_20XX.tgz One data file per day and per station in it's own directory. Directory structure in each archive: ./<yyyy>/<mm>/<dd>/<wmoid>/<data-file> (yyyy=year, mm=month, dd=day, wmoid=5-digit WMO station ID) File name synop10min_<wmoid>_<yyyymmddhhmmss>_1.0days.txt, e.g. synop10min_10747_20200101000000_1.0days.dat 6 header lines preceded by "#" One line for each 10-minute interval Space-separated format in 7 columns Parameters in each column defined in header line No. 6: # end-time T2M[°C] RH2M[%] P10min[mm] CLC[oct] FF[m/s] DD[°](end time of 10-min interval, 2-m temperature, 2-m relative humidity, accumulated precipitation from rain gauges, total cloud cover, wind speed and wind direction) Station metadata See the more or less self-explanatory text file station_metadata_LNM_20250713_utf8_simplified-names_no-duplicates.txt This file gives for each WMO-ID the name, geographic longitude, latitude, station height AMSL and the time span of its existence (begin time and end time). There are 181 stations altogether given in the file. However, not all the stations have been operational all the time. Some stations have been closed, moved, or newly installed during the 5 years, so that less stations were active at each particular time (~150). There might be more than one line per station in the metadata file. In this case the station has been moved to different location(s) and the time interval of each location is given in the last two columns (FROM_DATE and TO_DATE). Basic software Todo: add python code snippets to read the data files and compute precipitation rate, particle size distributions and equivalent radar reflectivity factor. Further informations about the instrument Website of manufacturer: https://www.thiesclima.com/en/laser-precipitation-monitor/ https://www.thiesclima.com/en/precipitation-measuring-devices/laser+precipitation+monitor~5.4110.00.xxx/ In German language: https://www.thiesclima.com/de/niederschlag-messtechnik-geraete/laser-niederschlags-monitor~5.4110.00.xxx/ Detailed technical manuals from the manufacturer website (not specific for the DWD devices): https://www.thiesclima.com/en/db/dnl/5.4110.xx.x00_laser_precipitation_monitor_eng.pdf https://www.thiesclima.com/en/db/dnl/5.4110.xx.x00_laser_precipitation_monitor_eng_short.pdf In German language: https://www.thiesclima.com/de/db/dnl/5.4110.xx.x00_lnm_deu.pdf https://www.thiesclima.com/de/db/dnl/5.4110.xx.x00_lnm_deu_kurz.pdf[版本注释] 本版本并非最新版本！最新版本可通过以下链接获取：https://doi.org/10.5281/zenodo.19265418 本数据集更新版本基于2025年9月19日发布的版本，更新日期为2026年3月5日。 本次更新内容包括：清理了元数据文件中1个无激光降水测量仪（Laser Niederschlags Messer, LNM）的站点信息，移除该站点对应的SYNOP观测数据；新增2025年的LNM数据及补充SYNOP观测数据；对文档进行小幅修正，优化了LNM数据电文的格式说明。 ## 引言 作为其地面自动SYNOP观测站网络的天气数据监测体系的一部分，德国气象局（Deutscher Wetterdienst, DWD）持续运行约150台激光光学雨滴谱仪（laser-optical disdrometers），即Thies厂商生产的激光降水测量仪（Laser Niederschlags Messer, LNM）。 该设备可对穿过水平定向激光片的所有粒子（雨滴、霰粒、雪花、冰雹或其他任何粒子）的粒径及垂直下落速度分量进行记录。该激光片长度为22.8 cm，宽度为2.0 cm，高度为0.75 mm。 基于1分钟内记录的所有粒子，可构建二维离散分布（分为20×22个下落速度-粒径分级区间的计数数据），并推导出多项降水特征积分参数，例如降水率、依据世界气象组织（World Meteorological Organization, WMO）ww表估算的降水类型、等效雷达反射因子（equivalent radar reflectivity factor）、粒子粒径分布（particle size distribution）等。 对于德国气象局的业务观测而言，仅需依据SYNOP报告生成的估算降水类型即可。不过，每分钟的二维下落速度-粒径分布原始数据也会被记录，但并未存入德国气象局的官方长期数据库中。 鉴于这些原始数据在云物理学、数值天气预报及雷达气象学领域对国际科研团队具有极高的研究价值，我们通过Zenodo平台发布了2019年至2025年期间德国境内总计不少于150个站点的大型原始数据集。 本数据集附带多项用于质量控制与交叉校验的补充参数，包括10分钟分辨率的气温、相对湿度、雨量筒累积降水量、总云量、风速及风向数据，同时也提供了所有相关的站点元数据。 德国气象局针对不同的SYNOP站点运行了两款不同版本的LNM软件，即版本2与版本3，两款软件的电文内容存在差异。 ## 文档说明 以下为本数据集的核心信息，压缩归档文件Documentation.tgz中附带了若干PDF文档： 1. 针对德国气象局版本3设备的技术手册（仅提供德语版本）： - LNM_manual_Thies_deu_kurz.pdf（简明手册） - LNM_manual_Thies_deu.pdf（详细手册） 2. 针对两款设备版本的数据格式及粒径-速度分级区间的英文说明文档： - LNM_telegram_engl_v2+v3.pdf - LNM_classes.pdf 3. 从厂商官网下载的、非德国气象局专属版本的英文手册（适用于版本2设备）： - 5.4110.xx.x00_laser_precipitation_monitor_eng_short.pdf（简明手册） - 5.4110.xx.x00_laser_precipitation_monitor_eng.pdf（详细手册） ## 仪器说明 德国气象局专属版本的LNM的简要及详细说明已以德语提供，详见上文。针对该专属版本的英文手册暂未发布，但我们从厂商官网下载了适用于新型仪器版本的英文手册，并一并放入Documentation.tgz归档文件中。厂商官网链接详见下文。 ## 数据文件与格式 ### 雨滴谱仪数据 以年度为单位的gzip压缩tar归档文件，命名格式为lnm_thies_DWD_20XX.tgz 每个归档文件中按站点与日期分目录存储数据，每日每个站点对应一个数据文件。归档文件内的目录结构如下： ./<yyyy>/<mm>/<dd>/<wmoid>/<data-file> 其中yyyy为年份，mm为月份，dd为日期，wmoid为5位世界气象组织站号（WMO station ID）。 数据文件命名格式为<V>_<wmoid>_<yyyy>-<mm>-<dd>.txt，其中V为1位仪器版本号，仅可为"2"或"3"。例如："3_10474_2023-07-01.txt" 每个数据文件内每行对应1分钟的测量间隔（理论上每日文件包含1440行数据），采用分号分隔格式，每行包含多条记录。 每条记录的详细说明可参考LNM_telegram_engl_v2+v3.pdf文档，粒径与下落速度分级区间的定义可参考LNM_classes.pdf文档。 每行的时间戳为测量分钟的近似UTC结束时间。由于时间同步的技术问题，时间存在约30秒的误差，因此我们将时间四舍五入至最近的整分钟。 由于异常数据流传输问题导致数据不可恢复，部分每日文件中可能会缺失1至5分钟的数据，因此并非所有文件都包含完整的1440行数据。 针对部分站点仅部分时段运行的日期所生成的数据文件已被移除，例如站点在当日停机、安装，或遭遇停电及其他运行中断情况的日期。 ### 补充SYNOP观测数据 以年度为单位的gzip压缩tar归档文件，命名格式为synop10min_DWD_20XX.tgz 每个归档文件中按站点与日期分目录存储数据，每日每个站点对应一个数据文件。归档文件内的目录结构如下： ./<yyyy>/<mm>/<dd>/<wmoid>/<data-file> 其中yyyy为年份，mm为月份，dd为日期，wmoid为5位世界气象组织站号。 数据文件命名格式为synop10min_<wmoid>_<yyyymmddhhmmss>_1.0days.txt，例如："synop10min_10747_20200101000000_1.0days.dat" 文件前6行以"#"开头的标题行，每行对应1个10分钟间隔的观测数据，采用空格分隔格式，共7列数据。 各列参数的定义可参考第6行标题行： # 结束时间 2米气温[°C] 2米相对湿度[%] 10分钟累积降水量[mm] 总云量[oct] 风速[m/s] 风向[°] 各参数分别为：10分钟间隔的结束时间、2米高度气温、2米高度相对湿度、雨量筒10分钟累积降水量、总云量（八分制）、风速及风向。 ### 站点元数据 站点元数据可参考文本文件station_metadata_LNM_20250713_utf8_simplified-names_no-duplicates.txt，该文件内容直观易懂。 该文件为每个WMO站号提供了站点名称、地理经度、纬度、海拔高度（相对于平均海平面）以及站点运行的时间跨度（开始时间与结束时间）。 文件中共包含181个站点，但并非所有站点全程处于运行状态。部分站点在5年观测期内曾被关闭、迁移或新建，因此在任意特定时段内活跃的站点数量约为150个。 元数据文件中可能存在单个站点对应多行记录的情况，此时代表该站点曾被迁移至不同位置，最后两列（FROM_DATE和TO_DATE）标注了对应位置的运行时间区间。 ## 基础软件 待办事项：添加用于读取数据文件并计算降水率、粒子粒径分布及等效雷达反射因子的Python代码片段。 ## 仪器相关补充信息 厂商官网链接： 英文页面： https://www.thiesclima.com/en/laser-precipitation-monitor/ https://www.thiesclima.com/en/precipitation-measuring-devices/laser+precipitation+monitor~5.4110.00.xxx/ 德文页面： https://www.thiesclima.com/de/niederschlag-messtechnik-geraete/laser-niederschlags-monitor~5.4110.00.xxx/ 从厂商官网下载的详细技术手册（非德国气象局专属版本）： 英文版本： https://www.thiesclima.com/en/db/dnl/5.4110.xx.x00_laser_precipitation_monitor_eng.pdf https://www.thiesclima.com/en/db/dnl/5.4110.xx.x00_laser_precipitation_monitor_eng_short.pdf 德文版本： https://www.thiesclima.com/de/db/dnl/5.4110.xx.x00_lnm_deu.pdf https://www.thiesclima.com/de/db/dnl/5.4110.xx.x00_lnm_deu_kurz.pdf