It is a relatively new active remote sensing technology using a laser scanner, Global Positioning System (GPS), and inertial navigation. In the same way that SONAR using sound waves and reflection to detect targets and determine distance (think of the ping in the submarine scene from your favourite war movie), LiDAR uses laser pulses with their timed reflectance to determine the target distance. With airborne LiDAR, the target is what lays under the aircraft – be it power lines, vegetation, or the ground.
Topographic LiDAR offers unmatched speed of terrain data capture along with survey grade precision. 100’s of square kilometers can be acquired in weeks that would otherwise take traditional ground survey months to even years to complete. LiDAR is the ideal dataset to find surface structures and lineaments missed by satellite imagery and aerial photography purely because they are hidden under forest canopy or obscured by dense vegetation.
LiDAR derived topography is one of the few exploration datasets that delivers value throughout the entire project lifecycle – from assisting with exploration to resource discovery, through to drilling, deposit modelling, mine design, and then finally site rehabilitation at end of project life. No other dataset provides such utility and cost efficiency to a project as does LiDAR.
Structural measurements made directly from the desktop – boots-on-ground fieldwork optional!
When of suitable resolution, LiDAR derived DEM’s are ideal for structural interpretation. Folds, faults, and lineaments can all be mapped and combined with your existing geological datasets. Bedding dip and fold plunge can also be measured from the LiDAR DEM quickly and with precision.
These structures observed in LiDAR can yield a regional perspective, as opposed to a localized trend that a field geologist could measure such as a fracture or even a outcrop that is not in-situ, deriving spurious results.
LiDAR is non destructive and ‘virtually’ removes the vegetation, allowing otherwise obscured geology to be seen
The image sequence below illustrates the power of LiDAR revealing geology. The grey hill shade is a common dataset in many maps and is great to display topography and is often combined with elevation contours within a map. LiDAR can reveal much more detail hidden in the topography itself- such as these linear intrusive features striking NNE/SSW that would have otherwise been completely undetected in the hill shade.
Thick forest and vegetation cover obscures topographic and geomorphic detail
Typical grey hillshade shows topography well, but geomorphology remains hidden
Enhanced hill shade derived from reprocessed LiDAR reveals subtle linear intrusive features that would have otherwise remained undetected
