Details

Autor(en) / Beteiligte

• Yamazaki, Dai
• Ikeshima, Daiki
• Tawatari, Ryunosuke
• Yamaguchi, Tomohiro
• O'Loughlin, Fiachra
• Neal, Jeffery C.
• Sampson, Christopher C.
• Kanae, Shinjiro
• Bates, Paul D.

Titel

A high‐accuracy map of global terrain elevations

Ist Teil von

• Geophysical research letters, 2017-06, Vol.44 (11), p.5844-5853

Ort / Verlag

Washington: Blackwell Publishing Ltd

Erscheinungsjahr

2017

Link zum Volltext

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• Spaceborne digital elevation models (DEMs) are a fundamental input for many geoscience studies, but they still include nonnegligible height errors. Here we introduce a high‐accuracy global DEM at 3″ resolution (~90 m at the equator) by eliminating major error components from existing DEMs. We separated absolute bias, stripe noise, speckle noise, and tree height bias using multiple satellite data sets and filtering techniques. After the error removal, land areas mapped with ±2 m or better vertical accuracy were increased from 39% to 58%. Significant improvements were found in flat regions where height errors larger than topography variability, and landscapes such as river networks and hill‐valley structures, became clearly represented. We found the topography slope of previous DEMs was largely distorted in most of world major floodplains (e.g., Ganges, Nile, Niger, and Mekong) and swamp forests (e.g., Amazon, Congo, and Vasyugan). The newly developed DEM will enhance many geoscience applications which are terrain dependent. Key Points A high‐accuracy global digital elevation model (DEM) was developed by removing multiple height error components from existing DEMs Landscape representation was improved, especially in flat regions where height error magnitude was larger than actual topography variation The improved‐terrain DEM is helpful for any geoscience applications which are terrain dependent, such as flood inundation modelling Plain Language Summary Terrain elevation maps are fundamental input data for many geoscience studies. While very precise Digital Elevation Models (DEMs) based on airborne measurements are available in developed regions of the world, most areas of the globe rely on spaceborne DEMs which still include non‐negligible height errors for geoscience applications. Here we developed a new high accuracy map of global terrain elevations at 3" resolution (~90m at the equator) by eliminating multiple error components from existing spaceborne DEMs. The height errors included in the original DEMs were separated from actual topography signals and removed using a combination of multiple satellite datasets and filtering techniques. After error removal, global land areas mapped with ±2m or better accuracy increased from 39% to 58%. Significant improvements were found, especially in flat regions such as river floodplains. Here detected height errors were larger than actual topography variability, and following error removal landscapes features such as river networks and hill‐valley structures at last became clearly represented. The developed high accuracy topography map will expand the possibility of geoscience applications that require high accuracy elevation data such as terrain landscape analysis, flood inundation modelling, soil erosion analysis, and wetland carbon cycle studies.