Roughness Spectra Derived from Multi-Scale LiDAR Point Clouds of a Gravel Surface: A Comparison and Sensitivity Analysis

摘要: The roughness spectrum (i.e., the power spectral density) is a derivative of digital terrain models (DTMs) that used as surface descriptor in many geomorphological and physical models. Although light detection ranging (LiDAR) has become one main data sources for DTM calculation, it still unknown how spectra are affected when calculated from different LiDAR point clouds, or they processed differently. In this paper, we three clouds 1 m × 10 gravel plot to derive analyze interpolated DTMs. were acquired using terrestrial laser scanning (TLS), both an unmanned aerial vehicle (ULS) airplane (ALS). corresponding derived first ensemble averaged periodograms then differences analyzed with dB threshold based on 95% confidence intervals periodograms. aim determine scales (spatial wavelengths) over which can be interchangeably. results show TLS scan measure wavelengths larger than cm two times its footprint size) up m, less 0.65 dB. For same threshold, ULS interchangeably about 1.2 dm five size). However, interpolation parameters should optimized make more accurate at smaller m. size was, however, too small draw particular conclusions ALS spectra. These novel high potential replace calculation applications.