Towards a Large-Scale 3D Modeling of the Built Environment—Joint Analysis of TanDEM-X, Sentinel-2 and Open Street Map Data

Abstract

Continental to global scale mapping of the human settlement extent based on earth observation satellite data has made considerable progress. Nevertheless, the current approaches only provide a two-dimensional representation of the built environment. Therewith, a full characterization is restricted in terms of the urban morphology and built-up density, which can only be gained by a detailed examination of the vertical settlement extent. This paper introduces a methodology for the extraction of three-dimensional (3D) information on human settlements by analyzing the digital elevation and radar intensity data collected by the German TanDEM-X satellite mission in combination with multispectral Sentinel-2 imagery and data from the Open Street Map initiative and the Global Urban Footprint human settlement mask. The first module of the underlying processor generates a normalized digital surface model from the TanDEM-X digital elevation model for all regions marked as a built-up area by the Global Urban Footprint. The second module generates a building mask based on a joint processing of Open Street Map, TanDEM-X/TerraSAR-X radar images, the calculated normalized digital surface model and Sentinel-2 imagery. Finally, a third module allocates the local relative heights of the normalized digital surface model to the building structures provided by the building mask. The outcome of the procedure is a 3D map of the built environment showing the estimated local height for all identified vertical building structures at 12 m spatial resolution. The results of a first validation campaign based on reference data collected for the seven cities of Amsterdam (NL), Indianapolis (US), Kigali (RW), Munich (DE), New York (US), Vienna (AT), and Washington (US) indicate the potential of the proposed methodology to accurately estimate the distribution of building heights within the built-up area.

National-scale mapping of building height using Sentinel-1 and Sentinel-2 time series

“…Thus, in contrast to ALS point clouds, height information is provided for buildings only; no further disentanglement between buildings and other vertical structures was necessary (as e.g. required by the approaches of Geiß et al (2019) and Esch et al (2020) ). As outlined in the introduction however, 3DBMs alone are insufficient to produce nation-wide building height maps, as they are only available for limited areas, where local administrations have decided on open data policies.…”

High-Resolution Gridded Population Datasets: Exploring the Capabilities of the World Settlement Footprint 2019 Imperviousness Layer for the African Continent

“…In this context, it is expected that with the upcoming validation of the WSF2019 products, these remaining uncertainties can be assessed, allowing a focus on further technical improvements to the WSF2019-Pop dataset. Considering this, future research will also include quantitative comparisons with other built-area datasets and population grids, and the integration of other geospatial layers into the modelling framework, such as the newly developed Global Urban Footprint 3D dataset [71]. Furthermore, as the semi-automatic methods presented here are completely transferable, future research will also focus on expanding the accuracy assessment of the WSF2019-Pop dataset to other countries.…”

Assessing Sustainable Urban Development Trends in a Dynamic Tourist Coastal Area Using 3D Spatial Indicators

“…3D information is rarely used for characterizing urban development at lower scales due to data unavailability. There are only a few studies on the vertical dimension of urban structures, either at lower scales [76] or for selected cities across the globe [12,[77][78][79]. This limitation can soon be overcome by the development of data fusion techniques for producing 3D spatial information from synthetic aperture radar (SAR) and optical image pairs [80].…”