An Optimization Method of Ambiguity Function Based on Multi-Antenna Constrained and Application in Vehicle Attitude...

Area of Science:

• Geomatics Engineering
• Navigation Systems
• Satellite Technology

Background:

• Global Navigation Satellite System (GNSS)-based multi-antenna attitude determination offers simple algorithms and no time-based error accumulation for long-duration operations.
• Vehicle attitude determination using GNSS can face challenges in simultaneously achieving fixed solutions for all antennas, potentially compromising precision and reliability if float or incorrect solutions are used.

Purpose of the Study:

• To propose a novel baseline-constrained ambiguity function method (BCAFM) to enhance the accuracy and reliability of vehicle attitude determination.
• To enable the replacement of unreliable real-time kinematic (RTK) float or incorrect fixed solutions with BCAFM-derived coordinates, thereby assisting direct attitude determination methods.

Main Methods:

• Development of a self-built four GNSS antenna hardware platform.
• Implementation of BCAFM incorporating baseline constraints to improve search efficiency and optimize the ambiguity function value (AFV) formula for enhanced true peak discrimination.

Main Results:

• Experimental verification using vehicle attitude determination and baseline length difference measurements.
• Demonstrated reduction in error peak function values and accurate identification of the true peak.
• A 14.95% increase in valid epoch proportion was observed when using BCAFM-derived coordinates.
• Achieved precision of 0.54°, 1.46°, and 1.15° for the three attitude angles.
• Root Mean Square (RMS) of baseline length difference was 3.8 mm.

Conclusions:

• The proposed BCAFM effectively improves the accuracy and reliability of GNSS-based vehicle attitude determination.
• The method successfully addresses the challenge of unreliable RTK solutions by providing accurate coordinate replacements.
• Optimized BCAFM enhances search efficiency and true peak identification, leading to significant improvements in valid data epochs and attitude precision.