Abstract:

Forest land with obvious open space was selected as modeling sample plot. The single-and multiple-echo airborne LiDAR data of the sample plot were obtained and analyzed in terms of three-dimensional coordinates distribution,reflection intensity distribution and vertical distribution. The forest digital elevation model (DEM) extraction method was developed using discriminant analysis. A closed forest with a large number of control points was selected for model validation. A total of 1 472 control points were measured. Results showed that it is feasible to extract DEM in the complex environment of the mountain forest using discriminant analysis method with variance of 0.05.Its accuracy can reach mean elevation difference 0.24 m. Data with elevation difference between -0.5 m and 0.5 m amounted for 93.85% of the total. The results from this study was compared to the ones obtained using direct grids/windows segmentation. It indicated that this method could have better simulation results.

Key words: airborne LiDAR, digital elevation model(DEM), discriminant analysis, multiple echo