Detection of Power Transmission Lines in LiDAR Data
The detection of power transmission lines is important for the electrical engineering society for assessing of the current situation of transmission lines and for further analysis (e.g. calculating electromagnetic field in nearby areas). In this research, we have developed a new method for detecting power transmission lines in a LiDAR dataset. As they are represented by linearly distributed sets of points above the ground, we detect areas on which they are located using the top-hat transformation based on the morphological opening. Thresholding is then applied in order to extract areas with high responses. Here, locally fitted surfaces are used twice. First they serve to extract power transmission lines, and then for identifying points representing a single conductor. In the last step the detection of the transmission towers is achieved. The proposed method is reliable and considerably fast as it can process 5 million points in less than 40 sec on an average PC. The detected power transmission lines may be utilized for versatile domain-specific tasks, including computation and visualization of electromagnetic field below the conductors and assessment of various geometric characteristics as, for example, lowering of a particular conductor, height of a conductor above the ground, distances between the conductors forming a power transmission line, vicinity of vegetation in transverse direction and vertical distance of tree tops to the conductors. Besides these monitoring activities, planning of the power transmission lines can also be importantly facilitated by LiDAR-based DTMs and extracted vegetation and buildings. Detection of power transmission lines (top), towers (middle) and conductors. 47 Estimation of electromagnetic field along the modelled corridors and assessment of other environmental impacts e.g the number and volume of trees to be cut, are of particular public interest.