Slope extraction algorithm of ski tracks based on airborne LIDAR point cloud

The slope information of ski resort is not only a necessary content for planning and construction of ski resort, but also an important data support for skiers to improve performance and reduce sports injuries. The traditional manual measurement method is time-consuming and the low temperature environment of the ski resort is not conducive to the long-time operation of the surveyors. In order to solve the problem of calculating the slope of ski tracks, an automatic slope extraction algorithm of ski tracks based on LIDAR point cloud was proposed. The projection difference of elevation filtering, clustering segmentation and other algorithms were used to preprocess the ski resort point cloud and obtain the feature data of ski tracks edge. An adaptive threshold fitting algorithm was proposed for the extraction of the center line of ski tracks. This algorithm could automatically select the threshold to fit the center line of ski tracks according to the point cloud quantity information and coordinate information, which eliminated the negative effect of the data sparse or missing of point cloud on the center line fitting. The data processing results show that the relative error between the slope value calculated by this method and the average value of multiple manual measurements is 2.2%. This method is of reference significance to the application of LIDAR in the target of ski resorts and to the calculation of slope of snow tracks in the mapping of ski resorts.