Characterization of Topography and Vegetation Structure using Dual-wavelength LIDAR and High-Resolution Stereo Imagery

Abstract:

This study examines the utility of co-collected, dual-wavelength, full-waveform LIDAR and high resolution stereo imagery to improve characterizations of topography and vegetation over two survey sites near Monterey, CA. Extraction of waveform features, such as total waveform energy, canopy energy distribution, and foliage penetration metrics are computed along the laser line-of-sight and along the vertical axis of synthesized “pseudowaveforms.” The pseudowaveform technique is a novel method that allows for direct comparisons between green (532nm) and near IR (1064nm) waveforms, despite variations in sampling. Comparisons between wavelengths allows for detailed characterization of vegetation structure and distribution not possible with single-wavelength LIDAR. Additionally, point clouds derived from stereo imagery are fused with LIDAR point clouds to increase resolution and improve accuracy of bare earth digital elevation models, further augmenting characterization of tree height and structure.