Differences Between LiDAR and Photogrammetry

Before the invention of the aeroplane, land surveying took place solely on the ground, with individuals manually taking measurements and doing strategic digs to determine things like rock density. Aeroplanes, though, eventually made it possible to survey and map out extensive areas from the sky. This process is still extensively used today, and is also still usually accompanied by on-the-ground surveying; however, the inclusion of aerial data provides more accurate results over greater distances.

As technology improved, so too did the means of land surveying. Currently, the two most commonly employed approaches to surveying are UAV LiDAR (unmanned aerial vehicle light detection and ranging) and photogrammetry.

UAV LiDAR surveys an area via the use of laser pulses that measure the distance between objects as well as between the starting point (i.e., the height at which the drone is flying) and the end point (i.e., the ground). This particular approach to land surveying is especially useful for those looking to save on costs but still gain accurate readings, as drones tend to be cheaper to operate than helicopters or planes. UAV LiDAR is also excellent for areas with a lot of ‘hinderance’ that could potentially negatively impact measurement accuracy – for example, a very wooded area or a city full of buildings.

By contrast, photogrammetry makes use of high-resolution photographs. Like UAV LiDAR, photogrammetry also makes use of drones. However, it differs in that rather than using lasers to measure points and then calculate area dimensions, it employs photographic stills taken at different vantage points that are then joined together to create an aerial-view 3D map.

Each approach comes with its own pros and cons, and individuals in need of surveying services would do well to consult with companies specialising in both in order to determine which would best meet their specific requirements.