High-Precision GNSS Technology Empowers UAV Flight Control Systems
Septentrio high-precision GNSS receivers, leveraging industry-leading centimeter-level RTK positioning capability and multi-antenna real-time orientation technology, form the core of accurate and reliable spatiotemporal information for UAV platforms based on the ArduPilot open-source flight control system. By supporting full-constellation multi-frequency signal tracking, integrating built-in AIM+ anti-jamming and anti-spoofing technology, and featuring APME+ multipath mitigation capability, these receivers ensure highly reliable and high-integrity positioning output for UAVs even under complex electromagnetic environments and dynamic flight conditions. With their high update rate and low latency performance, they seamlessly meet the real-time navigation and control requirements of the ArduPilot flight control system, providing millisecond-level response support for precise path tracking, autonomous takeoff and landing, and collaborative operations. Meanwhile, Septentrio high-precision GNSS receivers support a rich set of interface protocols and plug-and-play integration, significantly lowering the technical threshold for deploying high-precision GNSS in UAV systems. This empowers professional scenarios such as agricultural plant protection, surveying and mapping modeling, and infrastructure inspection to achieve centimeter-level autonomous flight, driving the advancement of industrial UAVs toward higher intelligence levels.
Core Technologies of Septentrio Receivers
AIM+ (Adaptive Interference Mitigation Software+)
- Protected Interference Types
Spurious peaks from radio amateurs and digital television
Non-malicious signal transmitting devices (e.g., amateur radios, TV transmitters) may generate unexpected strong signal peaks (spurious emissions) outside their operating frequency bands due to design flaws or malfunctions. These strong peaks can drown out weak satellite navigation signals, causing receiver signal loss of lock.
- Signals from Inmarsat and Iridium satellite systems
The frequency bands used by Inmarsat and Iridium satellite systems are adjacent to or partially overlap with GNSS frequency bands. Their powerful downlink signals can cause out-of-band blocking interference or adjacent-channel interference to nearby GNSS receivers.
- DME (Distance Measuring Equipment) pulse interference near airports
DME is an aviation navigation device operating in the 960-1215 MHz frequency band, which overlaps with the GPS L5 frequency band. The high-power pulse pairs it transmits can severely interfere with satellite signals, potentially leading to frequent satellite signal loss and unreliable positioning for receivers near airports.
- Wideband interference from chirp jammers
Chirp jammers are common malicious interference devices that rapidly and periodically scan a wide frequency band (e.g., the entire GNSS frequency band), generating transient but full-band strong interference. Traditional static filters are difficult to cope with such interference, which can effectively disable most commercial receivers.
Solutions Included in AIM+
The software addresses the above interference through the following advanced features:
- Adaptive notch filters and frequency band reconfiguration
Adaptive notch filters: The software can real-time monitor the frequency spectrum, automatically identify the center frequency and bandwidth of narrowband interference (e.g., spurious peaks, fixed-frequency interference), and dynamically generate a deep “notch” to filter it out while maximizing the retention of useful GNSS signals.
Frequency band reconfiguration: In the face of strong interference in specific frequency bands, the system can intelligently adjust its receiving strategy—for example, temporarily relying more on undisturbed frequency bands (such as L5), or recombining signals from different frequency bands to bypass interference. The mosaic P3H supports multi-antenna configuration, which can provide high-precision real-time heading measurements for PX4 systems without relying on magnetometers or initial movement.
- Unique resistance to chirp jammers
This is a prominent advantage of AIM+. The software algorithm is specially optimized for the fast time-varying characteristics of chirp signals. It may adopt time-frequency analysis technologies (such as Short-Time Fourier Transform) to track and predict the trajectory of chirp interference, and perform joint filtering or cancellation in the time-frequency domain, thereby effectively suppressing this most intractable wideband frequency-sweeping interference.
Onboard spectrum viewer for interference detection/location
It provides a visualization tool that allows operators to view the spectrum of the RF environment in real time.
Detection: Intuitively identify the presence, type, and intensity of interference signals.
Location: Combined with antenna arrays or mobile platforms, it can help determine the approximate direction or location of interference sources.
Diagnosis: Evaluate the effectiveness of anti-interference measures (such as AIM+). The high-stability reference clock of the mosaic P3H provides an accurate time benchmark for multi-sensor data fusion and synchronization in PX4 systems.
- Full-band high-precision real-time positioning
Supports all existing and future global navigation satellite systems, with 448 hardware channels for full-range signal coverage.
Delivers centimeter-level RTK positioning accuracy: 0.6 cm + 0.5 ppm horizontally and 1 cm + 1 ppm vertically, with initialization completed in just 7 seconds.
Offers a maximum update rate of 100 Hz and low latency of less than 10 ms, meeting the real-time requirements of high-dynamic UAV flight control.
Supports multiple standard interfaces and protocols, enabling seamless integration with open-source flight control systems such as PX4 and ArduPilot.
- Advanced interference protection and high reliability
Equipped with AIM+ industry-leading anti-jamming and anti-spoofing technology to effectively combat various electromagnetic interferences.
Integrates patented technologies including APME+ multipath mitigation, IONO+ ionospheric protection, and LOCK+ vibration-robust tracking.
Operates within a temperature range of -40°C to +85°C and complies with the MIL-STD-810G vibration standard, adapting to harsh environments.
Features typical power consumption of only 0.6 W, achieving a balance between high performance and low power consumption, with free lifetime firmware upgrades supported.
Advantages and Competitiveness of ArduPilot Open-Source Flight Control System
The ArduPilot open-source flight control system boasts the following significant advantages and competitive strengths:
Comprehensive functionality
Supports multiple vehicle types including multi-rotors, fixed-wing aircraft, helicopters, unmanned ground vehicles, unmanned surface vessels, and unmanned underwater vehicles, covering a wide range of scenarios from basic aerial photography to complex industrial applications. Its algorithms have been long-term verified, with mature and stable functions such as attitude control, navigation, and obstacle avoidance, capable of meeting practical needs in agricultural spraying, topographic surveying and mapping, logistics and distribution, etc.
Hardware compatibility
Can run on a variety of hardware platforms, including the early Arduino platform and modern Pixhawk series hardware. This flexibility allows users to select hardware based on budget and performance requirements, lowering the entry barrier, especially suitable for educational purposes and DIY enthusiasts.
Community and ecosystem support
Boasts a globally active developer community, providing abundant tutorials, documentation, and forum support. The ground station software Mission Planner features complete Chinese localization and user-friendly operation, enabling Chinese users to get started quickly. Continuous contributions from the community ensure rapid iteration of the system and timely fixing of issues.
Cost-effectiveness
Compared with commercial flight control systems, the main cost of ArduPilot open-source flight control lies in hardware procurement, while the software is free and can be freely modified. It is a cost-effective choice for projects with limited budgets or start-up enterprises.
Technical depth and scalability
The core code is based on C++, achieving cross-platform portability through the Hardware Abstraction Layer (HAL), facilitating developers to deeply customize algorithms or integrate new sensors. Its modular design supports functional expansion—advanced functions such as visual navigation and swarm flight can be realized through community plugins or secondary development.
Historical accumulation and stability
Born in 2007, ArduPilot has accumulated a wealth of actual flight data and experience over years of development. Its stability has been widely verified, especially demonstrating outstanding anti-interference capability and reliability in complex environments, making it suitable for application scenarios with high safety requirements.
Core Features of Septentrio AsteRx-m3 Pro+ and mosaic-X5 Receivers
Signal Tracking Capability
Common advantages: Both support full-system and full-frequency band operation (GPS, GLONASS, BeiDou, Galileo, QZSS, NavIC, SBAS), designed for future signals to ensure high availability worldwide.
Differentiated highlights:
AsteRx-m3 Pro+: Equipped with 544 hardware channels, supporting a wider range of signal types (such as GLONASS L3, Galileo E6), providing strong redundancy for complex environments.
mosaic-X5: Integrates 448 hardware channels, achieving efficient synchronous tracking of all visible satellites within an ultra-compact size.
Positioning Accuracy and Exclusive Functions
RTK accuracy:
Both deliver centimeter-level high-precision positioning:
Horizontal accuracy: 0.6 cm + 0.5 ppm
Vertical accuracy: 1 cm + 1 ppm
Exclusive functions:
AsteRx-m3 Pro+: Features a unique dual-antenna mode, capable of outputting sub-degree-level heading, pitch/roll angles (e.g., heading accuracy of 0.15° with a 1-meter baseline), completely eliminating reliance on vehicle dynamics or magnetic sensors.
mosaic-X5: Focuses on single-antenna high-dynamic positioning, making it an ideal choice for space-constrained applications.
Dynamic Performance and Power Consumption
Update rate and latency: Both support a maximum update rate of 100 Hz for position and measurement data, with event marking accuracy of <20 ns, meeting the stringent requirements of high-speed real-time control systems. The AsteRx-m3 Pro+ further boasts industry-leading low-latency characteristics.
Power consumption performance:
AsteRx-m3 Pro+: Achieves ultra-low power consumption RTK, with power consumption ranging from 750 mW (GPS L1/L2) to 1000 mW (full constellation), delivering excellent endurance performance.
mosaic-X5: Attains industry-leading ultra-low power consumption, with typical power consumption of only 0.6 W and maximum power consumption of 1.1 W, greatly extending the operating time of battery-powered devices.
Core Technology: GNSS+ and AIM+ Jointly Build a Security Barrier
Both are equipped with Septentrio’s proprietary GNSS+ technology suite and AIM+ anti-jamming and anti-spoofing system, ensuring stable operation in any challenging environment:
– AIM+: Industry-leading interference monitoring and mitigation technology, capable of countering narrowband, wideband, and frequency-sweeping interference, while providing anti-spoofing protection to ensure positioning and timing security.
– IONO+: Advanced ionospheric scintillation mitigation technology, effectively coping with space weather disturbances to ensure signal continuity.
– APME+: Post-correlation multipath estimation technology, significantly improving positioning accuracy and observation quality in complex reflective environments such as urban canyons and ports.
– LOCK+: Enhances tracking robustness, automatically adjusting parameters to resist high vibration and shock, preventing signal loss.
– RAIM+: Receiver Autonomous Integrity Monitoring, real-time detecting and eliminating erroneous observations caused by multipath or ionospheric disturbances.
Main Advantages of Integrating AsteRx-m3 Pro+ and mosaic-X5 with ArduPilot
AsteRx-m3 Pro+: Defining the New Standard for Professional-Grade ArduPilot Integration
Core positioning: Designed exclusively for professional applications with extreme requirements for accuracy, reliability, and functionality, it is the ultimate choice for high-end UAV system integration.
When your ArduPilot project targets precision agriculture, 3D surveying and mapping, scientific monitoring, or industrial inspection, the AsteRx-m3 Pro+ provides not just position data, but an absolutely reliable foundation for state perception and control.
Detailed Explanation of Core Integration Advantages
- Native protocol support for seamless connection
Directly outputs standard protocols such as NMEA 0183, RTCM 3.x, and Septentrio Binary Format (SBF), fully compatible with ArduPilot’s GPS driver stack, enabling out-of-the-box centimeter-level RTK positioning.
GNSS heading: A revolutionary attitude reference
Core value: In dual-antenna mode, it directly provides sub-degree-level GNSS heading and pitch/roll information without relying on magnetometers (heading accuracy of 0.15° with a 1-meter baseline).
- Transformations brought to ArduPilot:
Immunity to magnetic interference: Near high-voltage lines, steel structures, or onboard electronic devices, it completely solves flight instability and route deviation issues caused by magnetic compass yaw.
Improved control quality: Provides stable and accurate heading observations for the navigation filter (EKF), greatly enhancing control precision during hovering and path tracking (especially straight lines and polylines).
Simplified deployment: Eliminates the tedious steps of on-site magnetometer calibration, improving operational efficiency.
- AIM+ technology: Building an indestructible positioning defense line
Integrates an industry-leading anti-jamming and anti-spoofing (AIM+) engine. Whether facing unintentional wideband noise or malicious spoofing signals, it can perform real-time monitoring and mitigation. This ensures that the positioning data stream input to ArduPilot remains continuous and pure in any electromagnetic environment, guaranteeing flight safety and mission reliability from the source.
- Full-constellation support and GNSS+ robust core
Tracks full-frequency band signals from all major GNSS constellations (GPS, GLONASS, Galileo, BeiDou, etc.), providing unparalleled sky visibility and reliability. Built-in GNSS+ technologies including IONO+ (ionospheric mitigation), APME+ (multipath cancellation), and LOCK+ (vibration-resistant tracking) ensure fixed solutions and high precision even in the harshest environments such as dynamic scenarios, urban canyons, or active ionospheric conditions.
100 Hz high-frequency refresh to match high-dynamic performance
Delivers up to 100 Hz output of position and raw observation data, combined with event marking accuracy of less than 20 nanoseconds, perfectly matching the control frequency of high-speed autonomous aircraft to achieve precise and timely closed-loop control.
- Key Performance Parameters
– RTK accuracy: 0.6 cm + 0.5 ppm (horizontal) / 1 cm + 1 ppm (vertical)
– Update rate: 100 Hz (position and measurement data)
– Dual-antenna heading accuracy: 0.15° @ 1-meter baseline
– Power consumption: 750 mW (GPS L1/L2) to 1000 mW (full constellation, full frequency band)
– Interfaces: 4 × high-speed serial ports, USB, Ethernet, 2 × event markers
– Dimensions: 47.5 × 70 × 9.32 mm
- Typical Application Scenarios
– UAV precision agriculture (variable-rate spraying, seeding)
– Professional aerial surveying and photorealistic 3D modeling
– Power line inspection and infrastructure monitoring
– High-precision mobile base stations and dynamic positioning reference stations
mosaic-X5: Reshaping the Performance Benchmark for Compact ArduPilot Systems
Core positioning: Targeting mass production applications sensitive to size, power consumption, and cost, it achieves ultimate integration convenience without compromising performance.
For teams dedicated to developing the next generation of compact UAVs, robots, or autonomous devices, the mosaic-X5 condenses Septentrio’s cutting-edge technology into a palm-sized module, serving as a secret weapon to accelerate product time-to-market and maintain competitiveness.
- Detailed Explanation of Core Integration Advantages
– Innovative hardware design
– Ultra-compact size: Features a miniature surface-mount package of 31 × 31 × 4 mm, which can be directly soldered as a core component on custom flight control boards or carrier boards.
-Integration revolution: Completely eliminates the need for external GPS modules, connectors, and cables, greatly simplifying hardware design, reducing fault points, and improving overall system reliability. It is a key enabler for achieving product miniaturization and lightweight design.
– Protocol compatibility for zero-cost software adaptation
It also natively supports ArduPilot standard protocols such as NMEA and RTCM. From prototyping to mass production, no modifications are required to your software stack, significantly saving development and maintenance costs.
- Built-in AIM+ technology: Endowing consumer-grade products with professional-grade protection
It brings the same top-tier anti-jamming and anti-spoofing technology to the mainstream market. This ensures that your logistics UAVs, inspection robots, or high-end consumer devices possess superior robustness and security compared to peers when facing an increasingly complex wireless environment.
Milestone-level ultra-low power consumption
With typical power consumption of only 0.6 W, this breakthrough indicator allows the use of smaller batteries or directly extends mission time by more than 30%, which is crucial for applications pursuing long endurance.
– Designed for automated mass production
The standard SMT pad design perfectly fits high-speed automated pick-and-place production lines, ensuring consistent product quality and highly competitive unit costs, making it an ideal choice for large-scale production.
- Key Performance Parameters
– RTK accuracy: 0.6 cm + 0.5 ppm (horizontal) / 1 cm + 1 ppm (vertical)
– Update rate: >100 Hz (position)
– Hardware channels: 448 for synchronous tracking of all visible satellite signals
– Power consumption: 0.6 W (typical) / 1.1 W (maximum)
– Weight: Approximately 7 grams
– Interfaces: 4 × UART, USB, Ethernet, SDIO, GPIO
- Typical Application Scenarios
– Small and medium-sized industrial UAVs (logistics, security inspection)
– Educational robots, service robots (AGV/AMR)
– Lightweight surveying and mapping UAVs and vertical takeoff and landing (VTOL) aircraft
– Any compact, battery-powered devices requiring high-performance GNSS
Application Recommendations for Integrating AsteRx-m3 Pro+ and mosaic-X5 Receivers with ArduPilot
Choosing between AsteRx-m3 Pro+ and mosaic-X5 for your ArduPilot project hinges on clarifying the project’s performance priorities and development stage.
If your project targets professional or industrial applications, with core requirements for precise orientation capabilities beyond conventional positioning, absolute reliability in extremely complex electromagnetic environments, and rich interfaces for system expansion, then the AsteRx-m3 Pro+ is your ideal choice. Designed specifically for high-end prototype development, professional equipment upgrades, and custom systems with stringent performance requirements, its dual-antenna GNSS heading function is a key differentiating advantage for performing advanced tasks such as precision agriculture and 3D surveying and mapping.
If your project focuses on productization and marketization, with primary goals of achieving extreme device miniaturization, ultra-long endurance, and optimal overall cost control, then the mosaic-X5 will be a more suitable solution. Its revolutionary surface-mount (SMT) integration method can completely transform hardware design, greatly simplifying production. It is the strongest enabler for developing new products from the PCB level and pursuing large-scale mass production and rapid market launch. While ensuring top-tier GNSS performance and anti-jamming capabilities, it perfectly balances size, power consumption, and cost.
In summary, choose the AsteRx-m3 Pro+ for ultimate performance and functionality; choose the mosaic-X5 for ultimate integration and commercial efficiency. Both are built on Septentrio’s same reliable GNSS+ technology core, ensuring that your ArduPilot system has a solid and trustworthy positioning foundation.
Summary
In the vast landscape of open-source flight control, ArduPilot has emerged as the preferred platform for the development of UAVs, robots, and various autonomous systems due to its exceptional stability and flexibility. However, the ultimate performance ceiling of such systems often depends on the precision and reliability of their “eyes” for perceiving the world—the GNSS receiver. As a global leader in high-precision positioning, Septentrio deeply understands the decisive role of sensor performance in defining system limits. Our AsteRx-m3 Pro+ and mosaic-X5, designed exclusively for demanding applications, are more than just positioning modules; they are the key to unlocking the full potential of ArduPilot and elevating your project from “usable” to “excellent”. Whether you are exploring the blue ocean of professional surveying and mapping or committing to the mass production of consumer-grade products, we can provide a top-tier positioning foundation that seamlessly integrates with the ArduPilot ecosystem.
How does Septentrio AIM+ technology address specific interference challenges faced by UAVs in complex electromagnetic environments?
Septentrio AIM+ technology tackles complex interference through a set of adaptive solutions: it leverages real-time spectrum monitoring and adaptive notch filters to accurately eliminate narrowband interference from sources such as amateur radios and satellite communications; it employs a unique time-frequency analysis algorithm to track and mitigate the most intractable chirp-type wideband frequency-sweeping interference; meanwhile, its onboard spectrum viewer provides environmental visualization, assisting users in diagnosing and locating interference sources. This ensures that UAVs can obtain continuous and pure positioning signals even in harsh electromagnetic environments such as airports and urban areas.
What are the differences in core advantages between AsteRx-m3 Pro+ and mosaic-X5 when integrated into the ArduPilot system?
The two receivers have distinctly different core advantage positioning: The AsteRx-m3 Pro+ is a benchmark for functionality and performance. Its unique dual-antenna design can directly provide sub-degree-level GNSS heading and attitude information for ArduPilot without relying on magnetometers, coupled with rich interfaces, making it the ultimate choice for high-end applications such as professional surveying and mapping and precision agriculture. In contrast, the mosaic-X5 is a model of integration and efficiency. Its stamp-sized surface-mount package can be directly soldered onto the flight control PCB, delivering equivalent centimeter-level RTK performance with ultra-low power consumption, and is specifically designed for consumer-grade or commercial UAV products pursuing miniaturization, long endurance, and mass production cost optimization.
What key improvements can the combination of the ArduPilot open-source flight control system and Septentrio receivers bring to professional-grade UAV applications?
The integration of the two has sparked a revolution in “reliable precision” for professional UAVs: The centimeter-level RTK positioning, 100 Hz high-frequency update rate, and AIM+ anti-jamming capability provided by Septentrio receivers infuse ArduPilot flight control with accurate, stable, and real-time spatiotemporal information. This empowers UAVs to achieve previously unattainable precise path tracking, stable hovering and operations in magnetically disturbed environments, as well as safe and reliable autonomous flight in complex electromagnetic scenarios, fully unlocking application potential in professional fields such as agriculture, surveying and mapping, and inspection.
What key factors should be considered when selecting AsteRx-m3 Pro+ or mosaic-X5 for integration with ArduPilot?
The decision should be based on the “demand, platform, and stage” triangle: If your project requires the highest-precision attitude orientation (e.g., 3D modeling) or operation in extreme environments, with ample space for platform size and power consumption, and is in the prototype or professional equipment development stage, then the fully-featured AsteRx-m3 Pro+ is the choice. Conversely, if your needs focus on core positioning performance, with strict constraints on size, weight, and endurance, the platform is committed to high integration, and the project is in the productization and mass production stage, then the ultra-compact, low-power mosaic-X5 is undoubtedly the better commercial choice.
