Light Detection And Ranging (LiDAR) technology provides most accurate input data source for utility mapping. High accuracy, operation from multiple platforms, and ability to survey through tunnels makes this technology unique for rail utilities. Lidar data can be acquired in discrete patches and later register to get a complete 3D point cloud of the rail corridor. Hence data handling and processing will be faster when comparing with other technologies. Another added advantage is that its feasibility to get minute details of the intricate features. Ability to collect RGB values along with intensity makes this technology most relevant for 3D model preparations. This will be of great help to rail engineering, designing and maintenance and constructing organizations. So survey grade spatial information can be collected in a faster pace with this kind of data. More over this data can be processes in multiple software platforms like Auto CAD, Leica Cyclone, Terra, Micro station and combination of these.
The mail application of lidar survey in rail utility mapping area
- Condition assessment of tracks and switches
- Digital rail asset register preparation
- Signage management
- Vegetation encroachment monitoring
- Corridor monitoring
- Corridor design
- Corridor maintenance
- Kinetic monitoring
Rail right of way area is an asset intensive corridor. So mapping these corridors is labor intensive. SBL has got the technical capabilities to map, capture features and model them in a 3D environment for various design and maintenance activities. In a recent project SBL geo spatial team has collected an exhaustive list of more than 100 features related to rail assets. These are ranging from base structures to huge bridges. Presentation of output files in various 3D models pertaining to rail assets was one of the peculiarities of the project. SBL has prepared the data in 3D wire face model, 3D surface model, MX GENIO format as well as in lexica true view formats. Initially all the features were captured as wire frames and later converted to surface models. A digital terrain model of the area has been created by classifying the data to ground and non ground categories. Trimming adjustment with digital terrain models were performed to bring the features to ground level and to obtain accurate height of the features.
Challenges of using lidar data in rail corridor mapping are a). Possibility of features missing due to low intensity of the point clouds, b). Masking of the features due to presence of debris, c). Blockage of features due to presences of temporary articles present over the area and d). Registration related issues.
Rail operators are benefited in using such kind of data due to
- It provides a complete digital record of all assets
- Change detection is very easy
- Encroachment of vegetation, unauthorized occupation and missing of features can be monitored
- Condition assessment is very easy
- Standard maintenance programme can be implemented and managed effectively.
- Alternate and optimal routes can be established for new tracks and yards
- Prefeasibility studies will became easy