Measurement of canopy geometry characteristics using LiDAR laser altimetry: a feasibility study

Airborne scanning laser altimetry offers the potential for extracting high-resolution vegetation structure characteristics for monitoring and modeling the land surface. A unique dataset is used to study the sensitivity of laser interception profiles and laser-derived leaf area index (LAI) to assumptions about the surface structure and the measurement process. To simulate laser interception, one- and three-dimensional (3-D) vegetation structure models have been developed for maize and sunflower crops. Over sunflowers, a simple regression technique has been developed to extract laser-derived LAI, which accounts for measurement and model biases. Over maize, a 3-D structure/interception model that accounts for the effects of the laser inclination angle and detection threshold has enabled the fraction of radiation reaching the ground surface to be modelled to within 0.5% of the observed fraction. Good agreement was found between modelled and measured profiles of laser interception with a vertical resolution of 10 cm.

[1]  J. Wilson,et al.  ANALYSIS OF THE SPATIAL DISTRIBUTION OF FOLIAGE BY TWO‐DIMENSIONAL POINT QUADRATS , 1959 .

[2]  David J. Harding,et al.  Satellite laser altimetry of terrestrial topography: vertical accuracy as a function of surface slope, roughness, and cloud cover , 1994, IEEE Trans. Geosci. Remote. Sens..

[3]  G. Campbell.  Extinction coefficients for radiation in plant canopies calculated using an ellipsoidal inclination angle distribution , 1986 .

[4]  J. Ross.  The radiation regime and architecture of plant stands , 1981, Tasks for vegetation sciences 3.

[5]  E. Walter-Shea,et al.  Test of an extended mathematical approach to calculate maize leaf area index and leaf angle distribution , 2001 .

[6]  Canopy architecture, irradiance distribution on leaf surfaces and consequent photosynthetic efficiencies in heterogeneous plant canopies. Part 1. Theoretical considerations☆ , 1986 .

[7]  J. Norman,et al.  Radiative Transfer in an Array of Canopies1 , 1983 .

[8]  R. Shaw,et al.  Leaf area measurements based on hemispheric photographs and leaf-litter collection in a deciduous forest during autumn leaf-fall , 1989 .

[9]  L. M. Dwyer,et al.  Mathematical characterization of maize canopies , 1993 .

[10]  W. Cohen,et al.  Surface lidar remote sensing of basal area and biomass in deciduous forests of eastern Maryland, USA , 1999 .

[11]  J. M. Norman,et al.  Indirect sensing of plant canopy structure with simple radiation measurements , 1988 .

[12]  R. Myneni,et al.  Canopy architecture, irradiance distribution on leaf surfaces and consequent photosynthetic efficiencies in heterogeneous plant canopies. Part II. Results and discussion , 1986 .

[13]  P. Monestiez,et al.  Modélisation de la structure géométrique du maïs , 1991 .

[14]  John R. Krebs,et al.  Improving bird population models using airborne remote sensing , 2000 .

[15]  Robert J. Gurney,et al.  Characterizing errors in airborne laser altimetry data to extract soil roughness , 2004, IEEE Transactions on Geoscience and Remote Sensing.

[16]  H Sinoquet,et al.  Canopy structure and light interception in Quercus petraea seedlings in relation to light regime and plant density. , 2001, Tree physiology.