LiDAR (Light Detection and Ranging) is an optical remote sensing technology which measures properties of scattered light to find range and/or other information of a distant target. Similar to radar technology, which uses radio waves instead of light, LiDAR determines the range to an object by measuring the time delay between transmission of a laser pulse and detection of the reflected signal. Airborne LiDAR surveys are a rapid, highly accurate and efficient method of capturing 3D data of large areas. LiDAR derived terrain models have proven advantageous across many industries and applications, such as forestry, mining, and energy. LiDAR deliverables offer users an accurate depiction of their project area, allowing them to better plan and allocate resources related to planning, design, and maintenance. Leading Edge Geomatics owns and operates several cutting edge topographic and bathymetric LiDAR systems.
With our advanced equipment, Leading Edge works with clients to determine the appropriate densities, scan angles, and deliverables to meet specific project needs. To date, LEG has collected over 500,000 km² of airborne LiDAR.
Digital Terrain Models (DTMs) provide a topographic model of the bare earth/underlying terrain of the earth’s surface. They are usually derived from Digital Surface Models (DSMs) by digitally removing the cultural (man-made) and vegetation features.
Digital Surface Models (DSMs) measure the height values of the first surface on the ground including terrain features, buildings, vegetation, and powerlines, providing a topographic model of the earth’s surface.
Digital Elevation Models are data files that contain the elevation of the terrain over a specified area, usually at a fixed grid interval over the surface of the earth. The intervals between each of the grid points will always be referenced to some geographical coordinate system. This is usually either latitude-longitude or UTM (Universal Transverse Mercator) coordinate systems.
The closer together the grid points are located, the more detailed the information will be in the file. The details of the peaks and valleys in the terrain will be better modeled with a small grid spacing than when the grid intervals are very large.
Intensity is a measure, collected for every point, of the return strength of the laser pulse that generated the point. It’s based, in part, on the reflectivity of the object struck by the pulse. Other descriptions for intensity include ‘return pulse amplitude’ and ‘backscattered intensity of reflection’.
Intensity is used as an aid in feature detection and extraction, LiDAR point classification, and as a substitute for aerial imagery when none is available.