GDEMM2024: 30 Arcsec Global Digital Elevation Merged Model 2024, a suite for Earth relief

We merged various digital elevation models (DEMs) published in the recent years and created an up-to-date composite and global solution for Earth’s topography and bathymetry. Compared to the original geographically limited data sets, the final product is a seamless merged grid which additionally provides high resolution and accuracy topography and depth globally.

We provide Earth relief grids w.r.t EIGEN-6C4 global geoid in terms of surface and bedrock elevation, ice thickness, and land-type masks which have been substantially improved w.r.t the global grids found in literature. We assessed the quality of the merged surface elevations w.r.t the heights given for about globally distributed 5000 ITRF stations. The merged surface model shows improvement of a factor of three w.r.t the other commonly used DEMs in terms of standard deviation. In addition to the four grids, GDEMM2024_SUR, GDEMM2024_BED, GDEMM2024_ICE, and GDEMM2024_LTM, we provide two additional files, the surface elevation without water (GDEMM2024_TBI) and the GDEMM2024_GEO file to transform the heights above EIGEN_6C4 geoid to ellipsoidal heights. The final grids are provided both in 30 arcsec and 1arcmin resolution and in GeoTIFF format which is one of the standards that is available in GMT (Generic Mapping Tools), GDAL (Geospatial Data Abstraction Library) and in almost all GIS software systems.

本研究整合近年发布的多款数字高程模型（Digital Elevation Model, DEM），构建了一套时效性优异的全球一体化地球地形与海底水深数据集。相较于原有的地理覆盖范围受限的数据集，最终产出的融合网格实现了全球无缝覆盖，且可提供高精度、高分辨率的全球地形与水深数据。

本数据集提供基于EIGEN-6C4全球大地水准面的地球地形起伏网格，涵盖地表高程、基岩高程、冰厚及土地类型掩码四类数据，相较现有文献中的全球网格产品已实现大幅优化。本研究基于全球约5000个国际地面参考框架（International Terrestrial Reference Frame, ITRF）站点的高程数据，对融合后的地表高程模型开展质量评估。相较于其他常用数字高程模型，本融合地表模型在标准差指标上的精度提升了三倍。

除GDEMM2024_SUR、GDEMM2024_BED、GDEMM2024_ICE及GDEMM2024_LTM四款网格数据外，本数据集还提供两类附加文件：一是无水体地表高程网格（GDEMM2024_TBI），二是用于将EIGEN-6C4大地水准面高程转换为椭球高程的GDEMM2024_GEO文件。最终产出的网格数据同时提供30角秒与1角分两种分辨率，格式采用GeoTIFF——这是通用制图工具（GMT, Generic Mapping Tools）、地理空间数据抽象库（GDAL, Geospatial Data Abstraction Library）以及几乎所有地理信息系统（GIS）软件均支持的标准格式之一。

搜集汇总

背景与挑战

背景概述

GDEMM2024是一个全球数字高程合并模型，提供了高精度和分辨率的地形和测深数据，包括地表高程、基岩高程、冰厚度和陆地类型掩膜等。该数据集在标准偏差方面比常用DEMs有三倍的改进，并以30弧秒和1弧分的分辨率提供，格式为GeoTIFF，兼容多种GIS软件系统。