Calculation of vegetation passability categories for vehicles based on laser scanning data

Abstract

Determining the categories of vegetation passability for vehicles (in forested areas) is a very popular and technically difficult task. Its complexity increases as the area of the territory increases, while duration of works and their cost should decrease. The passability of forests is influenced by elementary characteristics such as the species composition, the diameter of the trunks, the average distance between the trunks, etc. An example of such work is the construction of vegetation passability maps for vehicles by category. This task is in high demand during the construction of new facilities (pipelines, roads, railways) and the development of new deposits in the forest zone. One of the most promising methods of information support for solving this problem is airborne laser scanning and digital aerial photography. The disadvantage of this method (as well as all methods of remote sensing) is the practical impossibility of direct instrumental measurement of a number of vegetation parameters (despite 25 years of progress in the development of the lidar method), such as the diameter of the trunk, or its exact location. Increasing scan density, combined with the use of UAVs surveying at high angles to the vertical, allows these characteristics to be obtained at the cost of a significant decrease in productivity, an exponential increase in the cost of surveying and data processing, with little confidence in the obtained vegetation characteristics. This paper proposes an alternative approach based on the identification of relationships between characteristics that can be directly measured from low-density laser scanning data (crown height, coverage density, range of distribution of points of laser reflections in height relative to the ground) and vegetation passability categories measured in the field conditions. The obtained results show high reliability. A positive feature of this approach is the low cost and high productivity in determining the categories of terrain passability.