Drone / Aerial Mapping

When there is a need for topographic mapping of a large area, a cost-effective way to obtain information and collect data is an Aerial Survey. A series of aerial photographs, or digital images, are taken and then put together to form a three-dimensional model of the land. From this three-dimensional model topographic information such as contours, buildings, lakes and ponds can be extracted. In addition, a color picture that can be overlaid onto that topographic map, this process is called a digital orthophoto and is different from a standard photo in that it is at true scale anywhere on the photo.

An Aerial Survey is a great tool for developing large or hard to access sites. The advantage to an Aerial Survey is that it is not necessary to physically walk the entire project site to gather information. However, the Aerial Survey does require “targets” to be set and a ground control network tied together that can be seen from the air. If there is dense tree cover you can’t see the ground to determine contour information; likewise, if there is dense bush or even tall grass, the contours may reflect the top of the bush or grass, not the ground.

Drones and indeed even other commercial airplanes can attach other sensors to acquire what is known as remotely sensed data. Remote because the capture (sensing) of information is done at a distance. LIDAR is now one such common technology that is used to capture millions of ground points so as to generate a Digital Terrain Model and extract contours therefrom.