Document: WEN-3-89-19

Modeling lidar waveforms using a geometric and optical radiative tranfer model for discontinuous plant canopies.

NI, W.* ¹, R.DUBAYAH ¹ and J.B.BLAIR ²

University of Maryland, College Park, MD 20742 USA ¹
NASA Goddard Spaceflight Center, Greenbelt MD ²

Abstract:
Recent studies have explored the use of lidar remote sensing for retrieving forest structural characteristics in anticipation of the launch of NASA's Vegetation Canopy Lidar, a space-based mission that will provide a global sampling of vertical canopy structure. While field-based comparisons have had good success in relating lidar data to parameters such as canopy height, canopy closure, and biomass, among others, physically-based remote sensing models are necessary to better understand and interpret the interaction of lidar energy with the canopy. A Geometric Optical and Radiative Transfer (GORT) model for estimating the radiation environment within discontinuous plant canopies previously has been used to model canopy lidar waveforms for single layer, single species coniferous forests where trees are highly clumped. In order to apply GORT to plant canopies with more complicated canopy structure, we have extended it to model lidar returns from clumped multiple layers with multiple species. The model is validated using data acquired by the airborne Laser Vegetation Imaging Sensor (LVIS). By allowing us to model lidar waveforms based on the physical principles of radiative transfer, GORT provides a needed link between observed and actual canopy vertical structure.

Keywords: lidar, canopy radiative transfer

This abstract is being presented at: 3:15 PM in session:
Oral Session #64: Remote Sensing.