Performance improvement for GPS single frequency kinematic relative positioning under poor satellite visibility

Area of Science:

• Geodesy and Geomatics
• Satellite Navigation Systems
• Signal Processing

Background:

• Accurate kinematic relative positioning using Global Positioning System (GPS) single-frequency is challenged by satellite visibility fluctuations and motion.
• Resolving carrier phase ambiguities is critical but difficult in dynamic scenarios with intermittent satellite signals.

Purpose of the Study:

• To develop a robust recursive estimation method for GPS single-frequency kinematic relative positioning.
• To enhance ambiguity resolution reliability under challenging environmental conditions like satellite setting/rising events and limited visibility.
• To accelerate initialization in motion and improve overall positioning accuracy and availability.

Main Methods:

• A recursive estimation method combining GPS code and carrier phase measurements.
• An ambiguity dimension expansion method leveraging partial ambiguity relevance between successive observations.
• Integration of all available information into the recursive estimation for improved least squares adjustment.

Main Results:

• The proposed method demonstrates success in ambiguity estimation independent of satellite setting/rising events.
• Robust performance is achieved even with poor satellite visibility, enhancing positioning reliability.
• Experimental validation in urban environments confirms improved reliability and availability of relative positioning.

Conclusions:

• The developed recursive method with ambiguity dimension expansion significantly improves GPS single-frequency kinematic relative positioning.
• The algorithm offers a reliable solution for challenging environments, overcoming limitations of traditional methods.
• This approach enhances the practical usability of GPS for dynamic positioning applications.