If you're considering drone surveying at a site, you'll probably want to know a bit about how the process achieves results. Here are five things customers of aerial drone surveying contractors should know.
Multiple Systems
One major advantage of conducting aerial surveys with drones is that several systems are used to get data points. Most drones employ some form of GPS to keep tabs on where they're at in space. It's also common to use camera photography and LIDAR.
Where the magic happens is when the different data points come together. By using multiple reference points, you can compare the data to what you know from previous surveys and county-level data. This allows you several ways to reduce potential errors in a survey.
GPS
Working from signals from global-position satellites, a drone surveying team can quickly determine within a few feet where the vehicle is at. Over time, the accumulation of GPS data points also allows them to rule out errors and produce increasingly accurate data as the drone continues flying.
A significant benefit of this is that a drone can fly quickly to specific GPS coordinates. If you need to get surveying data from several corners of a property, for example, all the surveyor has to do is punch the coordinates for those points into the system and follow them.
Photography and Photogrammetry
The onboard camera makes it easy to snap images of a property. You can then map these images to known points based on the drone's GPS data and existing maps of the land.
Photogrammetry software also makes it easy for you to compile images from multiple positions and angles into a single product. In addition to the 2D map this produces, it's possible to use the images and data to compile 3D models, too. Likewise, you can cross-reference the imagery to existing survey data to confirm accuracy.
LIDAR
A cousin of RADAR, LIDAR is a tool that uses light rather than radio waves to perform range finding. A pulse goes out until it hits an object or the ground, and then it bounces back. The LIDAR sensor can calculate information about the surveyed area based on the time the light wave took to return, its intensity, and how much scattering occurred.
Compilation
The goal is to compile the thousands or millions of data points an aerial drone surveying system collects by these varied methods. These can be used to produce maps, survey data points, and even 3D models. You also can submit the data, models, and imagery as supporting documentation.