Drone LiDAR survey and Photogrammetry of HV Feeders for Vegetation Defect Mapping

Vegetation defect mapping along 4km of HV Feeders within surburban rail corridor


Vegetation management for high voltage feeders, and rail corridor in general, is a major area of asset maintenance for railway operators across the globe. A section of rail corridor contains several areas of protected Blue Gum forests, which are in close proximity to two high voltage feeders. The need to maintain safe vegetation clearances while also maintaining environmental protection requirements had raised concerns about the location of a new feeder alignment. Sydney Trains approached Diodrone to develop a detailed vegetation defect mapping and clearance survey for HV feeders.

Classified Point Cloud
Classified Point Cloud
Google Earth and GIS reporting
Google Earth and GIS reporting

Diodrone developed a methodology involving drone LiDAR data acquisition and processing to analyse and assess the vegetation clearances in relation to the high voltage feeders. Diodrone personnel carried out 6 drone flights which captured LiDAR and photogrammetry data for the 3.8km of rail corridor.

Initially, LiDAR data was classified into ground, HV feeders, overhead wiring structures, 1500V OHL and buildings. The classified data then allowed for analysis of the vegetation to conductor clearances along the length of the two feeders, with defects reported in GoogleEarth compatible file formats, which field crews then use to execute work orders.

Classified point cloud detailing various asset categories including powerlines, 1500V OHL, OHWS, terrain, ballast and buildings
The classified point cloud, accurate to 50mm and detailing various asset categories including powerlines, 1500V OHL, OHWS, terrain, ballast and buildings.

Additionally, the survey report identified several areas where the existing pole location data was incorrect.

Included with the survey data is a complete topographic survey, survey of all structures and signals and ballast profiles for almost 4km of suburban rail corridor.

Vegetation defect mapping reported through GoogleEarth and GIS compatible formats
Vegetation clearance defects are reported in GoogleEarth and GIS compatible formats, allowing for easy distribution to field crews for scoping and works execution.
Imagery was captured and processed in photogrammetry software to generate a 3D model for visual inspection of the rail line and encroachment of vegetation.