Multisensor and Multispectral LiDAR Characterization and Classification of a Forest Environment

Abstract

Abstract. Airborne LiDAR is increasingly used in forest carbon, ecosystem, and resource monitoring. For practical design and manufacture reasons, the 1064 nm near-infrared (NIR) wavelength has been the most commonly adopted, and most literature in this field represents sampling characteristics in this wavelength. However, due to eye-safety and application-specific needs, other common wavelengths are 1550 nm and 532 nm. All provide canopy structure reconstructions that can be integrated or compared through space and time but the consistency or complementarity of 3D airborne LiDAR data sampled at multiple wavelengths is poorly understood. Here, we report on multispectral LiDAR missions carried out in 2013 and 2015 over a managed forest research site. The 1st used 3 independent sensors, and the 2nd used a single sensor carrying 3 lasers. The experiment revealed differences in proportions of returns at ground level, vertical foliage distributions, and gap probability across wavelengths. Canopy attenuation was greatest at 532 nm, presumably due to leaf tissue absorption. Relative to 1064 nm, foliage was undersampled at midheight percentiles at 1550 nm and 532 nm. Multisensor data demonstrated differences in foliage characterization due to combined influences of wavelength and acquisition configuration. Single-sensor multispectral data were more stable but demonstrated clear wavelength-dependent variation that could be exploited in intensity-based land cover classification without the aid of 3D derivatives. This work sets the stage for improvements in land surface classification and vertical foliage partitioning through the integration of active spectral and structural laser return information.

Threshold loss of discontinuous permafrost and landscape evolution

“…b) during the first two weeks of August in 2008, 2011, and 2015, and for the entire basin in 2010. In 2008, 2010, and 2011, a Teledyne Optech Inc. Airborne Laser Terrain mapper (ALTM) 3100 EA (Toronto, Canada) (Chasmer et al ., ) was used, while the 2015 data set was acquired with an Optech Aquarius topographic/bathymetric laser mapping system (Hopkinson et al ., ). Aerial survey control was afforded using a Global Positioning System (GPS) base station located at the Fort Simpson Airport.…”

Quantifying Boreal Forest Structure and Composition Using UAV Structure from Motion

“…Airborne lidar data are routinely used to quantify three-dimensional forest structure [12][13][14][15] and link field measurements with coarse resolution remote sensing data. Given the cost to acquire airborne lidar data, targeted sampling is often conducted in coordination with ground survey data to inventory large forested areas [16][17][18].…”

Capability Assessment and Performance Metrics for the Titan Multispectral Mapping Lidar

“…It is important to note that a research group in Canada has used Titan data and other multi-sensor lidar data to assess the impact of multispectral lidar data on forestry studies [35]. They have observed similar return ratio differences among the Titan channels as the ones presented in this section.…”

“…Performing more complex intensity corrections and ground cover classification experiments is outside of the scope of this paper. However, it is worth mentioning that other research groups are performing such experiments based on Titan data with very promising results [29,35], while others have been actively working on the field of radiometric calibration of single and multispectral lidar intensities [4,6,7,17,36].…”