Abstract

The integration of the Septentrio mosaic‑X5 GNSS receiver with the ArduPilot open-source flight control system provides a highly reliable, centimeter-level navigation and positioning solution for UAVs and various autonomous vehicles. This solution fully leverages the technical advantages of the mosaic‑X5, including its all-system, all-band support (tracking all visible constellations such as GPS, BeiDou, and Galileo), anti-jamming (AIM+), anti-multipath (APME+), and low power consumption (typically 0.6 W). It seamlessly connects with mainstream hardware like Pixhawk via a standard serial port (UART) and enables rapid deployment by utilizing the rich software ecosystem of ArduPilot. Post-integration, it achieves real-time positioning with a 100 Hz update rate and latency below 10 ms, delivering horizontal accuracy of 0.6 cm + 0.5 ppm and vertical accuracy of 1.0 cm + 1 ppm. This significantly enhances the control precision and mission reliability of the system during high-speed flight, in complex electromagnetic environments, and during long-range operations. This solution is suitable for high-end application scenarios such as precision agriculture, 3D mapping, power line inspection, and scientific research experiments, making it an ideal choice for building professional-grade autonomous systems.

Q&A

What are the key hardware connection considerations when integrating a Septentrio GNSS receiver with a Pixhawk 4?

Hardware connection requires special attention to power supply and interface compatibility. First, ensure that the Septentrio receiver (e.g., AsteRx-m3 Pro+) is provided with a stable power supply of at least 3.3V, which can be achieved via the Micro-USB port or the dedicated power pins on the 44-pin cable. Secondly, when connecting the RIB board to the Pixhawk 4 flight controller, it is essential to use the COM2 interface on the RIB board. This is because the voltage level of its output matches the serial port input requirements of the Pixhawk flight controller, ensuring signal compatibility and preventing communication failures or hardware damage due to voltage mismatch. The connection cable must be the dedicated CBL_UAS_44-pin to Autopilot cable (Part No. 215947), and the 6-pin JST GH connector must be correctly plugged into the UART & I2C B port on the Pixhawk 4. How to configure ArduPilot firmware to correctly receive and parse SBF data sent by the Septentrio receiver?

How to verify that the Septentrio GNSS receiver has been successfully integrated with the Pixhawk 4 flight controller and is functioning properly?

Verification can be performed intuitively through the Mission Planner ground control station software:

-Basic Positioning Verification: After successfully connecting to the flight controller, observe the GPS status display in the “Flight Data” screen. If the GPS2 status shows “3D Fix” or a similar message, and the UAV’s icon is correctly displayed on the map, it indicates that the Pixhawk 4 is successfully receiving and parsing position data from the Septentrio receiver.

-Heading Function Verification (if dual antennas are configured): After enabling the dual-antenna configuration and completing relevant settings, check if heading angle (yaw) data from the GNSS is displayed on the Mission Planner interface. Its value should update stably as the orientation of the antenna baseline changes.

-Configuration Persistence Verification: To ensure the receiver’s configuration is not lost after power loss, you must copy the “Current” configuration to the “Start-up” configuration and save it in the “Management” > “Configuration” menu of its web interface. This action saves the settings to non-volatile memory.

Why is it necessary to configure and save the start-up configuration via the web interface when using a Septentrio receiver?

Because the Septentrio receiver’s runtime configuration is only stored in volatile memory and will be lost after a power cycle. You must use the “Management > Configuration” menu in its web interface to copy the current configuration to the “Start-up” configuration. This permanently saves the settings to non-volatile memory, ensuring that all parameters, including the SBF data stream output, remain effective after the device restarts.

When using only a single antenna, what essential SBF messages need to be output by the Septentrio receiver?

For basic positioning requirements, you must configure a 10Hz SBF data stream output on the COM2 port containing at least the following core messages: “PVTGeodetic” (providing position, velocity, time), “DOP” (dilution of precision), “VelCovGeodetic” (velocity covariance), “BaseVectorGeod” (baseline vector), and “ReceiverStatus” (receiver status). These messages collectively provide the complete information required for the flight controller’s navigation solution.

High-Precision GNSS Technology Empowers UAV Flight Control Systems

In the era of autonomous flight, precise spatiotemporal information is the cornerstone of UAV intelligent decision-making. The Septentrio mosaic‑X5 GNSS receiver redefines high-precision navigation standards with cutting-edge technology, providing a powerful and reliable position and orientation core for UAV systems based on open-source flight controllers like ArduPilot. The Septentrio mosaic‑X5 GNSS receiver, with its centimeter-level RTK positioning and multi-antenna real-time heading capabilities, serves as an ideal high-precision navigation core for professional UAV flight control systems. It ensures reliable operation in complex environments through advanced anti-jamming and anti-spoofing technologies and seamlessly integrates with open-source flight control platforms like ArduPilot via standard serial protocols for rapid deployment. Whether for precision agriculture, 3D mapping, or power line inspection, the mosaic‑X5 provides UAVs with a stable and trustworthy position and heading reference, significantly enhancing mission accuracy and autonomy. It is a key technological choice for enabling high-end UAV applications.

Introduction to ArduPilot Open-Source Flight Control System

ArduPilot is a long-established and powerful open-source flight control system. Here is its brief introduction:

Development History

-Founded in 2007 by the DIY Drones community, initially based on APM (ArduPilot Mega) hardware using the Arduino open-source platform.

-After 2013, it collaborated with the Pixhawk hardware platform, expanding to support more high-performance hardware and gradually evolving into a universal autopilot system supporting multiple vehicle types.

Core Features

-Multi-Vehicle Support: Supports multi-rotors, fixed-wing aircraft, helicopters, VTOL (Vertical Take-Off and Landing) aircraft, unmanned ground vehicles, unmanned surface vehicles, and unmanned underwater vehicles, applicable to a wide range of scenarios.

-Hardware Compatibility: Can run on mainstream flight controller hardware such as the Pixhawk series and Cube series, and can also be ported to Linux devices like Raspberry Pi, offering strong hardware adaptability.

-Rich Functionality: Features autonomous navigation, sensor fusion, various mission modes (e.g., mapping, obstacle avoidance, spraying, payload release), and integration with vision/language models for navigation, meeting the needs of complex tasks.

-Open-Source License: Uses the GPLv3 license, emphasizing pure open-source collaboration. Modified code must be open-sourced, making it suitable for academic research and open-source community collaboration.

Software Architecture

-Operating System: Initially used bare-metal scheduling; later introduced real-time operating systems like ChibiOS RTOS, improving system stability and real-time performance.

-Communication Protocol: Uses the MAVLink protocol for communication with ground control stations. Supports various GCS software, such as Mission Planner (Windows) and QGroundControl (cross-platform), enabling parameter configuration, mission planning, and real-time monitoring of the vehicle.

Community and Ecosystem

-Has a large global community with numerous developers and users, rich tutorials and documentation, and fast response to issues.

-Collaborates with organizations like the Dronecode Foundation to promote the standardization and ecosystem development of open-source drone technology, providing strong support for academic research, industrial applications, and enthusiasts. ArduPilot, with its mature features, broad hardware compatibility, and active community ecosystem, stands as a benchmark in the open-source flight control field. It is especially suitable for developers and users with needs for multi-vehicle support and open-source collaboration.

Core Advantages of the Septentrio mosaic‑X5

The mosaic‑X5 is a GNSS module designed for high-dynamic, high-reliability applications. Its small size, all-frequency-band capability, strong anti-interference features, and ultra-low power consumption make it easy to integrate with ArduPilot main controller boards, together forming a powerful, compact, and efficient high-precision navigation solution.

All-System, All-Frequency GNSS Performance

-448 hardware channels, supporting simultaneous tracking of all visible GNSS satellite signals.

-Full constellation support: GPS, BeiDou, Galileo, GLONASS, QZSS, NavIC, SBAS.

-Multi-frequency reception enhances signal availability and robustness in complex environments.

-Supports future signals and security services like OSNMA, ensuring system future-proofing.

GNSS+ Technology Ensures Stable Operation in Complex Environments

Integrates patented technologies like AIM+, APME+, LOCK+, and IONO+ to ensure the system powered by ArduPilot delivers stable, high-precision positioning outputs in various challenging environments:

-AIM+: Provides anti-jamming and anti-spoofing protection against complex electromagnetic environments.

-APME+: Effectively suppresses multipath effects, improving accuracy in urban canyons and near-ground operations.

-LOCK+: Maintains stable satellite tracking under high-dynamic and vibration conditions.

-IONO+: Mitigates the effects of ionospheric disturbances, ensuring reliability worldwide.

Sustained Centimeter-Level RTK Positioning Performance:

-Horizontal accuracy: 0.6 cm + 0.5 ppm

-Vertical accuracy: 1.0 cm + 1 ppm

Integration Advantages of mosaic‑X5 with ArduPilot

High Frequency, Low Latency for High-Dynamic Control

A 100 Hz update rate and latency below 10 ms ensure the flight control system receives near-real-time precise position information. This enables accurate trajectory control, rapid response, and stable hovering during high-speed flight, meeting the stringent demands of applications like racing drones and high-speed inspection platforms.

Seamless Integration and Rapid Development

-Hardware Compatibility: Standard interfaces like UART (4x), Ethernet, and USB allow direct connection to common ArduPilot main controller boards (e.g., Pixhawk series).

-Protocol Support: Fully outputs standard protocols like NMEA, RTCM, and RINEX. ArduPilot firmware natively supports or can parse this data through simple configuration.

-Development Ecosystem: Provides free SDK, API, and detailed documentation, lowering integration barriers and accelerating product development and testing cycles.

High Efficiency Supports Long-Endurance Missions

Typical power consumption is only 0.6 W, minimally impacting UAV endurance. Fast RTK initialization (<7 seconds) reduces mission preparation time, making ArduPilot-based UAV platforms more suitable for long-duration, large-scale, high-precision operational tasks.

Robust and Reliable, Adaptable to Diverse Environments

Complies with MIL‑STD‑810G vibration resistance standards. Operating temperature range from -40°C to +85°C ensures the integrated system can operate stably in various outdoor environments, from extreme cold to heat, and from plains to mountainous areas.

mosaic‑X5 + ArduPilot: Building Professional-Grade Autonomous Systems

Enhances Overall System Performance and Value

Infuses the ArduPilot platform with military-grade, high-precision, high-reliability GNSS capabilities. Significantly improves the navigation accuracy, environmental adaptability, and mission success rate of the entire system, enabling it to handle more professional and commercial application scenarios.

Lowers Development Barriers and Total Cost of Ownership

Based on mature open-source flight control and a plug-and-play high-precision GNSS module, developers can quickly build high-performance autonomous systems without needing to develop complex positioning algorithms from scratch. This drastically shortens R&D cycles and optimizes overall project costs.

A Forward-Looking Positioning Investment

Choosing the mosaic‑X5 equips your ArduPilot project with a positioning core that is currently industry-leading and future-proof for evolving signals. It protects long-term investments and prepares you to confidently meet future developments in autonomous driving and precise positioning technologies.