RTK drones used for drone mapping provide GPS accuracy and order of magnitude better than consumer-grade GPS units. It makes the RTK drones a viable mapping and 3D scanning solution where precision is critical for real-world applicability.
Consumer-grade drones utilize consumer-grade GPS units and compasses. These provide accuracy that can be wildly different depending on various conditions. Environment, location, internet connectivity, and many other factors might limit the overall accuracy of these units. And even if we reach the best possible conditions, we would still measure absolute accuracy in meters.
Hence, other, more profound technologies like RTK are required to guarantee precise mapping and surveying. This article will explain what RTK means and how it works.
What Is RTK?
RTK stands for real-time kinematic. The goal of RTK is to correct GPS location data in real-time while the drone is flying over and surveying the chosen area.
Why is it important? To understand this, let’s compare drones that take advantage of RTK technology with those which do not.
Consumer-grade drones have regular built-in GPS. The drone receives its position data from the satellites. Theoretically, if the drone is working correctly, it will hover in the sky like a tripod without moving. It certainly seems that way when using a drone, but the drone utilizes other sensors to hover in a single spot. Compass, IMU, and visual obstacle avoidance sensors help the drone to be stable. But all of these technologies hide that GPS data is nowhere near precise enough to enable such operation.
The RTK data can be this precise. RTK is the same GPS signal, but it can provide an absolute accuracy of 1 centimeter instead of meters.
How Do RTK Drones Work?
RTK equipped drones use a base station for GPS corrections. A base station is a stationary object with defined precise coordinates. The drone communicates with the base station in real-time, hence the name, and receives GPS corrections multiple times per second.
Base stations can be of several types. A portable base station can come in a kit with an RTK drone, which can connect to more satellites than a simple GPS unit and use that data to get a precise location. Or there can be commercial or national base station grids established throughout the country. In this case, the drone connects to this grid via the internet and receives corrections. These grids contain many base stations which already have fixed precise coordinates.
RTK equipment in Lithuania can use the national LITPOS station grid for precise corrections.
RTK technology is not a new word in the drone industry. Still, it is relevant and in demand, as many businesses choose them to cover needs in drone mapping or surveying.
RTK drones provide a high level of survey-grade accuracy. They demand fewer or almost no ground control points and improve mapping efficiency in different aspects.