Airborne Laser Scanning
Complete processing for Airborne Survey
Airborne laser scanning
Airborne laser scanning (ALS) is a remote sensing technique used for mapping of topography, vegetation, urban areas, ice, infrastructure roads and rivers. Airborne laser scanning is a rapid, highly accurate and efficient method of capturing 3D data of large areas, such as agricultural or forestry sites, urban areas, industrial plants, etc. Virtuematic has built a very strong national and international reputation as a leading practitioner of these services. We are known and trusted by local government as well as major private sector corporations across a range of industries.
LiDAR (Light Detection and Ranging) sensors acquire details of both the terrain and any above-ground features such as vegetation and infrastructure, with accuracy and resolution unparalleled by other airborne methods. Our fleet of aerial LiDAR sensors can emit up to two million laser pulses per second producing large-scale, high-density, and high-accuracy three-dimensional models of the landscape, whether it be rural, urban, or metropolitan environments.
Advanced classification on the terrain is used to classify bare earth and above ground features like vegetation, building, bridges, vehicles and other objects. 3D point cloud will be classified using automated macro and additional manual classification improvements applied to ground level and above ground points asper the client requirement. Point cloud classification is prepared ready for ground level terrain modelling, vegetation analysis, extraction of building footprints and surfaces.
Routine inspection of power line corridor is critical for securing uninterrupted distribution of electricity. 3D models of power line infrastructures are important data assets for power line corridor management. Objects that are difficult or impossible to measure with traditional techniques can be detected with LIDAR due to the high density of the point sampling and the active remote sensing approach. Informed by accurate location information and high spatial resolution, decisions in design and planning, management, and maintenance can be made with fewer uncertainties.
Vegetation is extracted from the full classified dataset. This product is useful for vegetation health, growth and density analysis. Vegetation models can be delivered on ground terrain or as a normalized dataset. A normalized product depicts vegetation on normalized ground (i.e., ground data has been flattened giving no height differences due to terrain).
Buildings can be extracted from LiDAR data as two or three-dimensional georeferenced vector layers. Footprints depict the location of buildings and can be used for detecting changes in building size, location, numbers and measuring front, side and rear setbacks. Building footprints can be overlaid on an orthophotograph, which is also a by-product of a LiDAR survey.
DTM –
We provide regular three-dimensional DTM datasets by classifying and filtering vegetation, man-made and other above ground features. A true representation of the bare earth surface is depicted once non-ground points are removed from the dataset. Filtered DTM can be delivered in LAS, xyz, dxf, dwg, csv or any other client requested format.
DSM –
Digital Surface Models are georeferenced regular grid datasets representing the first reflected surface detected by the sensor and will include surface features such as vegetation and man-made objects.
DEM –
Digital Elevation Model (DEM) is a raster image that holds z values, it is used widely during the analysis process where surface height value are important.
Hydro-flattening is the process of creating a Lidar-derived DEM in which water surfaces appear / behave as they would in traditional topographic DEMs created from photogrammetric digital terrain models.
Virtuematic digitizes hydrology features and edge-of-water breaklines using stereo-intensity images in a 3D dataset. Planimetric maps will include all hydrology and select man-made features (such as bridges and dams) that affect hydrological flow.
Contours are automatically generated from the bare earth surface model produced from a LiDAR survey. Contour intervals can be determined by the client and is dependent on the requested vertical accuracy.
Feature and break line extraction from LiDAR and image data delivered in client specified vector format.