GNSS Precise Relative Positioning Using A Priori Relative Position in a GNSS Harsh Environment

Area of Science:

• Geomatics Engineering
• Satellite Navigation Systems
• Geodetic Surveying

Background:

• Real-time kinematic (RTK) systems are crucial for Global Navigation Satellite System (GNSS) precise relative positioning.
• RTK systems face challenges with incorrect integer ambiguity fixing and long initialization times, especially with limited satellite visibility.

Purpose of the Study:

• To develop a novel GNSS carrier phase-based precise relative positioning method.
• To enable reliable and rapid integer ambiguity fixing, even in GNSS-challenging environments with few visible satellites.

Main Methods:

• Introduced a method utilizing a fixed baseline length and initial heading measurements.
• Developed an iterative integer rounding scheme for sequential ambiguity resolution based on satellite geometry and averaging epochs.
• Analyzed required averaging epochs through simulations considering baseline lengths and heading uncertainties.

Main Results:

• The proposed method achieved positioning accuracy better than 10 cm in static and dynamic field tests.
• Demonstrated significantly superior performance compared to conventional RTK solutions in GNSS-harsh environments.
• Successfully fixed integer ambiguities in a short time using the developed rounding scheme.

Conclusions:

• The novel GNSS positioning method offers a reliable and efficient alternative to traditional RTK.
• The technique is particularly effective in environments with limited satellite visibility, providing high-accuracy relative positioning.
• Fixed baseline length and heading measurements are key enablers for rapid and accurate integer ambiguity resolution.