Sky view factor calculation in complex urban geometry with terrestrial LiDAR

Abstract

ABSTRACT The sky view factor (SVF) is a key indicator in urban structures and is used in research in various fields. Recently, a method was developed to compute SVF in complex urban areas using airborne light detection and ranging (LiDAR). However, it displays low accuracy in areas with trees and buildings, owing to the limited resolution of airborne LiDAR data. In this study, the accuracy of the SVF calculation using terrestrial LiDAR was verified by comparing the reference data calculated from fisheye photographs at the same positions. Our results indicate that the SVF derived using terrestrial LiDAR has higher accuracy. We also tested whether a higher accuracy could be obtained by increasing the spatial resolution of the LiDAR data. The SVF estimation is more accurate when using terrestrial LiDAR, displaying a 60% reduction in the maximum error compared with the SVF estimated using airborne LiDAR. In addition, according to this research, a voxel size of 2.5 cm is sufficient for estimating SVF in a complex urban area. This resolution can be achieved through mobile LiDAR. Therefore, it is anticipated that the SVF calculation technique used in this study will be more practical when used with mobile LiDAR.