Effect Analysis of GNSS/INS Processing Strategy for Sufficient Utilization of Urban Environment Observations

Area of Science:

• Geomatics Engineering
• Navigation Systems
• Signal Processing

Background:

• Urban environments cause signal obstruction, degrading Global Navigation Satellite System (GNSS)/Inertial Navigation System (INS) accuracy.
• Intermittent satellite signal reception limits the performance of integrated navigation systems.

Purpose of the Study:

• To implement and evaluate a smooth post-processing strategy for tightly coupled GNSS/INS in urban environments.
• To enhance the accuracy and continuity of navigation solutions by fully utilizing GNSS and INS observations.

Main Methods:

• A tightly coupled differential GNSS/INS strategy using INS-estimated position for integer ambiguity reinitialization.
• Incorporation of GNSS raw observations into a Kalman filter for measurement updates.
• Application of the Rauch-Tung-Striebel smoothing (RTSS) algorithm for post-processing.

Main Results:

• The proposed strategy significantly improved positioning and attitude accuracy compared to traditional methods.
• The RTSS algorithm enhanced the navigation solution by effectively mining GNSS and INS observations.
• Continuous navigation results were maintained even in obstructed urban environments.

Conclusions:

• The developed smooth post-processing strategy effectively addresses GNSS signal occlusion challenges in urban areas.
• The integration of INS-aided integer ambiguity resolution and RTSS significantly boosts GNSS/INS performance.
• This approach ensures reliable and accurate navigation in environments with intermittent satellite visibility.