  Characterizing urban environments with broad coverages and high precision is
more important than ever for achieving the UN's Sustainable Development Goals
(SDGs) as half of the world's populations are living in cities. Urban building
height as a fundamental 3D urban structural feature has far-reaching
applications. However, so far, producing readily available datasets of recent
urban building heights with fine spatial resolutions and global coverages
remains a challenging task. Here, we provide an up-to-date global product of
urban building heights based on a fine grid size of 150 m around 2020 by
combining the spaceborne lidar instrument of GEDI and multi-sourced data
including remotely sensed images (i.e., Landsat-8, Sentinel-2, and Sentinel-1)
and topographic data. Our results revealed that the estimated method of
building height samples based on the GEDI data was effective with 0.78 of
Pearson's r and 3.67 m of RMSE in comparison to the reference data. The mapping
product also demonstrated good performance as indicated by its strong
correlation with the reference data (i.e., Pearson's r = 0.71, RMSE = 4.60 m).
Compared with the currently existing products, our global urban building height
map holds the ability to provide a higher spatial resolution (i.e., 150 m) with
a great level of inherent details about the spatial heterogeneity and
flexibility of updating using the GEDI samples as inputs. This work will boost
future urban studies across many fields including climate, environmental,
ecological, and social sciences.
