High-resolution coastal topobathymetries

High-resolution coastal topobathymetries dataset The High-resolution coastal topobathymetries product provides periodic beach topography and shallow water bathymetry measurements. The datasets include sand level measurements (elevation/altitude) covering the entire beach system, typically ranging from approximately +2 m to -15 m depth depending on the site. The output files are delivered in two different formats: very-high resolution multipoint datasets with a best point spacing of ~1 m, and gridded datasets with a spatial resolution of 10 m. The data product also delivers comprehensive quality control flags following established standards, ensuring the reliability of the topobathymetric measurements. Technical details The datasets are provided separately for each location in NetCDF format. Each file contains a time series of topobathymetric surveys, gridded on a 10 m grid along the time dimension, following the naming convention site_yyyy0_yyyy1_bathy.nc (e.g., clm_2011_2024_bathy.nc). The files include altitude/elevation parameters, their corresponding quality control flags, and additional metadata. Additionally, multipoint XYZ files at ~1×1 m resolution are generated per site and date, following the convention site_yyyymmdd_bathy.zip for bathymetric surveys and site_yyyymmdd_prof.zip for cross-shore profiles (e.g., clm_20220607_bathy.zip). All individual multipoint files for a given site are bundled together in a single compressed archive named site_yyyy0_yyyy1_bathy.zip (e.g., clm_2011_2024_bathy.zip). A combined multipoint file containing all survey dates merged into a single Shapefile is also provided per site, named site_yyyy0_yyyy1_bathy_merged.zip (e.g., clm_2011_2024_bathy_merged.zip). Each ZIP file contains an ESRI Shapefile in WGS84 coordinates and a JSON file with CF-compliant metadata. Parameters This product includes measurements of altitude (geometric height above the geoid) across the dry beach and shallow water domains. The parameters included in the dataset are listed below. Variable Long Name Units ALT Altitude / Geometric height above the geoid m ALT_QC Altitude quality flag dimensionless time Time days since 1950-01-01 latitude Latitude degrees_north longitude Longitude degrees_east Data sources Platforms: Valiant DR 620; human Instruments: BioSonics DT/DE Series Digital Echosounder; R2Sonic 2020 multibeam echosounder; Septentrio Altus RTK-GNSS; Leica GS10 RTK-GNSS; GEOMAX Zenith60 RTK-GNSS Data quality The accuracy of the topobathymetric measurements depends on the instrument, surveying method, and environmental conditions. The approximate horizontal and vertical positional accuracy for the altitude parameter is reported as 0.05 m. Topographic and bathymetric surveys are processed to correct, filter, and flag raw full-density data. The post-processing stage involves data point density reduction (thinning) and interpolation. A rigorous quality control (QC) procedure has been applied to the data. For topographic data (RTK-GNSS), an initial manual cleaning step removes spurious points. For bathymetric data (echosounders), the workflow involves both manual and automatic procedures to mitigate acoustic noise and non-physical outliers. Data points that pass these checks are assigned appropriate quality flags. For gridded products, cleaned measurements are resampled by averaging points within 10 m cells, and linear interpolation is used for gap filling. Interpolated cells are assigned a quality flag of 8. Spatial and Temporal coverage Site Longitude Range Latitude Range Elevation Range Period Cala Millor 3.3842 to 3.4016 39.5866 to 39.6145 -14.56 m to +2.66 m 2011-05-24 to 2024-10-01 (23 dates in NetCDF, 29 in multipoint*) Son Bou 4.0498 to 4.0801 39.8901 to 39.9085 -20.67 m to +2.80 m 2011-10-04 to 2024-10-23 (17 dates in NetCDF, 18 in multipoint*) Muro 3.1148 to 3.1321 39.8001 to 39.8191 -15.08 m to +2.86 m 2023-03-21 to 2024-06-05 (4 dates in NetCDF, 4 in multipoint*) *There are fewer NetCDF files than multipoint files because profile-only dates (non-bathymetry) were not resampled to a 10×10 grid for NetCDF generation and are instead provided as 1×1 multipoint data. Contact information For further technical inquiries or additional information about the dataset, please contact [e-mail]高分辨率海岸地形水深数据集 本产品提供周期性的海滩地形与浅海水深测量数据。数据集涵盖覆盖整个海滩系统的沙面高程（海拔/几何高度）测量值，其范围通常依测区不同而在约+2米至-15米水深之间波动。输出文件包含两种格式：一是最优点间距约1米的超高分辨率多点数据集，二是空间分辨率为10米的格网数据集。本数据集产品还附带遵循既定标准的全面质量控制标记，以保障地形水深测量数据的可靠性。 ## 技术细节 数据集按测区分开提供，采用网络通用数据格式（NetCDF）存储。每个文件包含地形水深测量的时间序列数据，沿时间维度被网格化至10米格网，命名遵循`site_yyyy0_yyyy1_bathy.nc`格式（例如`clm_2011_2024_bathy.nc`）。文件包含海拔/高程参数、对应的质量控制标记以及额外元数据。此外，针对每个测区和测量日期，会生成分辨率约为1×1米的多点XYZ文件，命名规则为：水深测量文件采用`site_yyyymmdd_bathy.zip`，跨岸剖面文件采用`site_yyyymmdd_prof.zip`（例如`clm_20220607_bathy.zip`）。单个测区的所有单点文件会被打包至一个名为`site_yyyy0_yyyy1_bathy.zip`的压缩归档文件中（例如`clm_2011_2024_bathy.zip`）。每个测区还会提供一个整合了所有测量日期数据的合并多点文件，存储为单个ESRI形状文件（ESRI Shapefile），命名为`site_yyyy0_yyyy1_bathy_merged.zip`（例如`clm_2011_2024_bathy_merged.zip`）。每个ZIP压缩包均包含采用世界大地测量系统1984（WGS84）坐标系的ESRI形状文件，以及符合CF（Climate and Forecast）元数据规范的JSON格式元数据文件。 ## 参数说明 本产品涵盖干滩与浅水区的海拔测量值（即大地水准面以上的几何高度）。数据集包含的参数如下表所示： | 参数代号 | 参数全称 | 单位 | | --- | --- | --- | | ALT | 海拔/大地水准面以上几何高度 | 米 | | ALT_QC | 海拔质量控制标记 | 无量纲 | | time | 时间 | 自1950-01-01起的天数 | | latitude | 纬度 | 北纬度数 | | longitude | 经度 | 东经度数 | ## 数据来源 测量平台：Valiant DR 620；人工测量 测量仪器：BioSonics DT/DE系列数字测深仪；R2Sonic 2020多波束测深仪；Septentrio Altus实时动态差分全球导航卫星系统（RTK-GNSS）；Leica GS10实时动态差分全球导航卫星系统（RTK-GNSS）；GEOMAX Zenith60实时动态差分全球导航卫星系统（RTK-GNSS） ## 数据质量 地形水深测量的精度取决于所用仪器、测量方法与环境条件。海拔参数的近似水平与垂直位置精度为0.05米。 地形与水深测量的原始高密度数据会经过校正、滤波与标记处理。后处理阶段包括数据点密度降采样（抽稀）与插值处理。本数据集已采用严格的质量控制（QC）流程。针对地形数据（实时动态差分全球导航卫星系统（RTK-GNSS）采集数据），首先通过人工清理步骤剔除虚假点；针对水深数据（测深仪采集数据），则采用人工与自动结合的流程来抑制声学噪声与非物理异常值。 通过上述检查的数据点会被赋予对应的质量控制标记。对于格网产品，经清理的测量数据会通过对10米格网单元内的点取平均值进行重采样，并采用线性插值填补数据空白，插值得到的格网单元会被赋予质量标记8。 ## 时空覆盖范围 | 测区名称 | 经度范围 | 纬度范围 | 高程范围 | 测量周期 | | --- | --- | --- | --- | --- | | 卡拉米约尔（Cala Millor） | 3.3842 ~ 3.4016 | 39.5866 ~ 39.6145 | -14.56米 ~ +2.66米 | 2011-05-24 至 2024-10-01（网络通用数据格式（NetCDF）文件含23期数据，多点数据集含29期数据*） | | 松布（Son Bou） | 4.0498 ~ 4.0801 | 39.8901 ~ 39.9085 | -20.67米 ~ +2.80米 | 2011-10-04 至 2024-10-23（网络通用数据格式（NetCDF）文件含17期数据，多点数据集含18期数据*） | | 穆罗（Muro） | 3.1148 ~ 3.1321 | 39.8001 ~ 39.8191 | -15.08米 ~ +2.86米 | 2023-03-21 至 2024-06-05（网络通用数据格式（NetCDF）文件含4期数据，多点数据集含4期数据*） | * 网络通用数据格式（NetCDF）文件数量少于多点数据集，原因是仅包含剖面测量（非水深测量）的日期未被重采样至10×10米格网以生成NetCDF文件，这类数据仅以1×1米的多点数据形式提供。 ## 联系方式 如需进一步咨询技术问题或获取该数据集的额外信息，请联系[e-mail]。