Centimetre-Level UAV Navigation Without RTK Base Stations
Why GNSS is the Critical Backbone of UAV Autonomy
The promise of fully autonomous unmanned aerial vehicles lives or dies on the quality of positioning and navigation data. UAVs conduct complex activities, including geospatial surveys, precision landings, and beyond visual line of sight (BVLOS) navigation. The quality of positional awareness determines the boundaries of what can be achieved safely and reliably.
Standard GNSS receivers leave UAV OEMs with trade-offs:
- Slow satellite acquisition extends pre-flight windows
- Heading accuracy is insufficient for demanding autonomous manoeuvres
- Positioning errors compound at altitude during BVLOS missions
For commercial UAV operators, these limitations affect productivity, certification, and competitiveness.
Hardware
ZED-X20D: Dual-Antenna GNSS Module
The ZED-X20D is a dual-antenna, all-band GNSS module designed for autonomous UAV navigation.
- Centimetre-level position accuracy
- Reliable heading without magnetic compasses
Dual-Antenna Heading Advantage
Unlike magnetometers, dual-antenna GNSS determines heading using satellite-based measurements, eliminating interference from power lines, structures, or onboard electronics.
Heading Accuracy
With ~1m antenna separation, sub-0.2° heading accuracy is achievable, outperforming IMU/magnetometer systems, especially in low-speed or hover conditions.
Drone Navigation
GNSS technology underpins reliable drone operations across agriculture, urban environments, and long-range missions.
Correction Services
PointPerfect Flex
PointPerfect Flex improves positioning accuracy from ~1.2m to 3–6cm without requiring RTK base stations, using cellular-delivered correction data.
Assisted GNSS (A-GNSS)
A-GNSS reduces Time to First Fix (TTFF) from minutes to seconds by delivering satellite data via terrestrial networks, enabling rapid deployment.
ZED-X20D + PointPerfect Flex
- Reliable heading from dual antennas
- Scalable centimetre-level positioning
- Fast startup with A-GNSS
Typical Use Cases
Precision Take-off & Landing
Consistent, accurate landing without interference or drift.
Photogrammetry
3–6cm accuracy reduces or eliminates the need for ground control points.
BVLOS Operations
Reliable positioning without dependence on base stations enables scalable long-range missions.
Performance Benefits
Faster Operations
Reduced startup time enables more daily sorties.
Lower Costs
No need for RTK base stations reduces infrastructure expenses.
Certification Ready
Supports documented accuracy and reliability for regulatory approval.
Scalable Across Platforms
Suitable for multi-rotor and fixed-wing UAVs.
Conclusion
ZED-X20D, ANN-MB2 antennas, PointPerfect Flex, and A-GNSS together provide a complete, scalable navigation stack for autonomous UAVs, combining accuracy, reliability, speed, and independence from ground infrastructure.
Courtesy of u-blox
