Abstract :
Traditional shading theory is based on DEM. For DSM, because of the complex manmade and natural ground objects such as buildings and vegetation, the elevation of DSM has the characteristic of discontinuity and abrupt, and the resulted shading map is poor in artistry and practicality. Color of terrain, construction, vegetation and other features may be similar on the shading map in certain area, and it´s difficult to recognize them from each other. Based on relief shading theory, this paper does an in-depth analysis in the issue above, and two relief shading methods are designed for DSM, one is based on LiDAR points and the other is based on nDSM. On the experiment result, it can be seen that the quality of shading map has been improved significantly. Both methods considered about the representation of terrain and features, terrain and features are distinguishable obviously on the shading map. Besides, based on classification of airborne LiDAR points, the two methods are useful for the application requirements of power, highway and other departments, and have important reference value in emergency management as well.
Keywords :
airborne radar; optical radar; terrain mapping; vegetation mapping; airborne LiDAR point cloud; buildings; classification information; complex manmade objects; digital elevation model; digital surface model; natural ground objects; relief shading theory; terrain color; terrain features; terrain representation; vegetation; Color; Image color analysis; Indexes; Interpolation; Laser radar; Lattices; Vegetation mapping;
