Overview
Ground control helps mitigate errors in standard drone positioning systems like GPS and image acquisition issues such as lens distortion or tilt. Its primary purpose is to provide "ground truth" to your drone data, ensuring that your digital maps accurately represent real-world coordinates.
In DroneDeploy, we achieve high accuracy through Ground Control Points (GCPs), Real-Time Kinematics (RTK), and Post-Processed Kinematics (PPK). These methods significantly improve the absolute positional accuracy of drone surveys, often reaching sub-inch or centimeter-level precision.
Why use ground control?
Standard drone GPS acts like a compass—it is reliable for general direction but lacks pinpoint precision. You should use ground control when the precise alignment of your map to real-world coordinates is necessary for your workflow.
Surveying: Every centimeter of alignment matters for land development and infrastructure projects.
Volume calculations: Comparing precise volumes of stockpiles or excavations over time requires consistent, accurate data.
3D modeling: Accurate ground control underpins detailed 3D models used for engineering analysis and simulations.
Foundational concepts
To master ground control, it is important to understand these key components:
Ground Control Points (GCPs): These are large marked targets on the ground with known GPS coordinates. They act as anchors that help the software position your map correctly in relation to the real world.
Checkpoints: These are physically identical to GCPs but are not used to process the map. Instead, they serve as independent validation points to measure the real-world accuracy of the final model.
RTK and PPK: These are GPS correction technologies that provide high-accuracy positioning directly to the drone during or after flight, often reducing the number of physical GCPs required on-site.
References and links
For more detailed information on implementing these workflows, please refer to the following resources:
v2.2