Root Cause:

RTCM data is transmitted to the flight controller.
After the flight controller processes and calculates the coordinates, it sends the latitude/longitude information to the main antenna.

• ​Data Transmission Path:
  1. Aircraft obtains ground RTCM data → transmits via telemetry link to flight controller → flight controller forwards to main antenna (delay may occur in this chain).
  2. Aircraft acquires network RTCM data → transmits through 4G antenna to domain controller → ​domain controller relays to co-controller → finally reaches main antenna.

​Troubleshooting Steps:

​1. For network RTK positioning:

• Check SIM card status.
• Inspect 4G antenna connectivity.

2. For ground RTK positioning:Verify network connectivity on the remote controller.

​3. For ground station positioning:

• Confirm ground station functionality.

​4. If issues persist:Replace positioning module (calibrate magnetometer).

​Root Cause:

​Abnormal Navigation Speed Measurement: The system detects an anomaly when the error between measured speed and fused speed exceeds a threshold. If the vertical velocity prediction value from the EKF differs from the observed value by more than a threshold for ​3 consecutive seconds, a navigation speed measurement anomaly is flagged.

Troubleshooting Steps:

​Post-landing Inspection:

• Check for loose arms, folded clamps, or damaged propellers.
• Verify secure installation of the flight controller case and positioning module.
• ​If issues persist, replace the flight controller.

​Root Cause: 

Excessive GPS signal discrepancy between primary and secondary antennas.

​Troubleshooting Steps:

（1）Check for obstructions or indoor environments.
​Note: Bridge underpasses are prohibited for operations (GPS signal loss may cause drone deviation and crash).

（2）Replace the positioning module.

（3）If unresolved, the flight controller's software cable may be disconnected; replace the flight controller.

Root Cause:
Discrepancy between dual-antenna RTK heading and geomagnetic heading solution exceeding 20 degrees triggers the alert.

Troubleshooting Procedures:

• Hardware Inspection

  • Check connectivity of the ​primary antenna feedline and ​both RTK antenna SMA connectors
  • Ensure no physical damage to coaxial cables

• ​System Recovery

  • Perform ​cold reboot of the flight controller 
  • If unresolved:
    ▸ Execute ​magnetic compass calibration