Aerial Precision: Unveiling RTK GPS Drones

RTK (Real Time Kinematic) GPS drones are revolutionising aerial mapping and surveying with their ability to achieve centimetre-level positioning accuracy. As drones continue to expand into professional applications, the heightened precision offered by these RTK systems allows users to collect highly accurate geospatial data for projects that demand precision, including construction site surveying, agriculture field mapping, and inspection of critical infrastructure.

What is RTK GPS?

RTK refers to a type of differential GPS that provides real-time corrections to improve positioning accuracy. It works by setting up a base station GPS receiver on a surveyed location. The data from the base station is then transmitted to rover units via radio, cellular, or satellite connections.

By comparing the signals the base and rover units receive, RTK systems can calculate error corrections and apply them to the rover’s position in real-time. This allows RTK GPS to achieve horizontal accuracies of 1-2 centimetres, compared to 5-10 meters for standard GPS.

RTK Drone Capabilities

Pairing RTK GPS with a mapping drone unlocks exceptional levels of aerial data accuracy and precision:

Precision Surveying and Mapping

Construction surveying, topographic mapping, and earthwork volumes traditionally rely on ground-based RTK GPS units or survey equipment. RTK drones provide a faster and more flexible way to survey sites while achieving comparable accuracy levels.

This 3D spatial data assists with engineering design, progress monitoring, calculating cut and fill volumes, and inspection of grade or elevation standards—detailed orthomosaic maps aid planning and documentation across natural resource, agriculture, and infrastructure projects.

High-Precision Inspections

RTK drone systems enable precise measurement and modelling of critical assets like cell towers, pipelines, bridges, mines, etc. Centimeter-level accuracy helps detect minute structural shifts or track erosion patterns.

Regular RTK drone inspections can provide early warnings to help prioritise maintenance needs or prevent catastrophic failures, especially for tall, enclosed, or challenging-to-access assets.

Accurate Volumetrics

For mining, construction, landscaping, and other projects involving the movement of earth or materials, RTK drones can rapidly calculate highly accurate cut and fill volumes. This eliminates the guesswork around progress tracking and payment quantities.

Operators can also perform precise stockpile surveys to optimise logistics planning and provide verification for invoicing of materials.

RTK Drone Hardware

There are a few standard components that make up an RTK drone system:

Rugged Multicopter Drone Frames

Hexacopter or octocopter drones provide a stable aerial platform capable of carrying RTK payloads and weather/wind resistance for data collection missions. Rugged carbon fibre frames with dust/water resistance allow these systems to operate across challenging environments.

Dual Frequency GNSS Boards + Antennas

By utilising multiple satellite constellations (GPS, Galileo, GLONASS, BeiDou) on dual frequencies, RTK systems achieve fast satellite lock and maintain centimetre accuracy even with partial sky blockages—low-altitude imaging benefits from multi-antenna configurations to minimise tilt errors.

RTK Modules

Self-contained RTK modules integrate the base and rover receivers into a single unit optimised for drone use. This simplifies field workflows without needing a separate base station setup. RTK modules transmit corrections via 900Mhz or WiFi for integration into the autopilot system.

Autopilots With RTK Integration

Autopilot firmware has a significant impact on RTK positioning performance. Advanced autopilots enable real-time transmission of RTK corrections to stabilise the drone’s position during flight. This also allows the creating of highly accurate camera trigger points for mapping and surveying missions.

RTK Field Workflows

While RTK drones remove many pain points from traditional surveying, there are still some critical steps required to leverage their exceptional accuracy:

Ground Control Points

Despite RTK providing real-time centimetre-level precision, establishing ground control points (GCPs) allows mapping outputs to be accurately georeferenced and oriented to real-world coordinates. This also includes quality assurance through independent checkpoints.

Base Station Setups

A single base station setup on a known surveyed point provides the highest accuracy for survey-grade applications across different sites and flights. A roving GNSS receiver can also act as its base station by occupying a point for an extended duration before each flight.

Careful Flight Planning

As with any drone mapping project, flight planning techniques like proper side/front lap overlap, flying grid patterns, and maintaining ideal speed & altitudes are critical for usable results. RTK merely enhances these standard workflows.

The Future of RTK Drones

As RTK drone hardware and data processing workflows progress, centimetre-level aerial accuracy will become accessible for increasing commercial and governmental applications.

Embedded Base Stations

Integrated RTK systems with an embedded base station receiver eliminate the need to set up a separate base station unit. This simplifies mapping pipelines across different sites or where survey control is unavailable.

Automated Workflows

Advances in autonomous flight, computer vision processing, and seamless data integration will minimise the need for manual piloting or data post-processing. This opens RTK drone capabilities to less specialised operators.

Expanded Applications

Heightened aerial precision provided by RTK systems continues to drive adoption for applications ranging from archeological site mapping and predictive crop analytics to rail/pipeline inspections and innovative city modelling.

With their unique combination of efficiency, flexibility, and exceptional accuracy, RTK multi-copter drones are poised to become indispensable tools for nearly any project requiring high-precision spatial data or analytics. Centimetre-level positioning unlocks game-changing aerial intelligence – helping organisations make better decisions, plan intelligently, track precisely, and model accurately.

Conclusion: 

RTK GPS drone technology represents a massive leap forward in aerial data accuracy and precision. As the hardware, software, and workflows behind these systems progress, centimetre-level mapping and modelling will become viable and affordable across an increasing range of commercial and governmental applications. RTK multi-copter drones are set to revolutionise inspection, surveying, volumetrics, and other processes that demand accurate geospatial intelligence by providing efficiently collected, exact spatial data. With their unique flexibility and accuracy, RTK drone solutions offer immense value that organisations across industries have only begun to tap into.