Multipath error in inertial navigation refers to GNSS signal distortion caused by signals reflecting off surfaces (e.g., buildings, water, terrain) before reaching the receiver. This results in incorrect positioning data, affecting the accuracy of GNSS-aided Inertial Navigation Systems (INS), especially in urban environments, forests, and mountainous regions.
How Multipath Error Affects INS?
Delayed Signal Reception – The GNSS receiver picks up both direct and reflected signals, causing positioning errors.
Reduced Navigation Accuracy – Incorrect GNSS updates introduce drift errors into the INS system.
Severe in Urban & Indoor Environments – Multipath is common in cityscapes, tunnels, and under bridges, leading to GPS signal instability.
How to Reduce Multipath Errors in INS?
✔ Multi-Frequency GNSS – Using L1, L2, and L5 signals helps identify and correct multipath distortions.
✔ Advanced GNSS Antennas – High-quality antennas with multipath rejection capabilities improve signal clarity.
✔ Sensor Fusion with INS – INS dead reckoning and LiDAR integration help maintain accuracy in GNSS-denied areas.
