Instantaneous Ambiguity Reinitialization and Fast Ambiguity Initialization for L1-L2 GPS Measurements

Area of Science:

• Geomatics Engineering
• Satellite Navigation Systems
• Signal Processing

Background:

• Global Navigation Satellite System (GNSS) ambiguity resolution is crucial for precise positioning.
• Existing methods often require extensive data or complex calculations.
• The need for robust and efficient ambiguity reinitialization, especially after signal loss, is critical.

Purpose of the Study:

• To introduce a Precise and Fast Method of Ambiguity Reinitialization/Resolution (PREFMAR) for Global Positioning System (GPS) L1 and L2 measurements.
• To develop a method for ambiguity initialization and reinitialization in relative positioning using minimal satellite and epoch data.
• To demonstrate the capability of instantaneous ambiguity reinitialization for precise real-time kinematic (RTK) navigation.

Main Methods:

• The PREFMAR method determines L1 (NL1) and L2 (NL2) ambiguities using specialized ambiguity functions.
• It utilizes GPS measurements from only two satellites and a single measurement epoch.
• The method does not require a variance-covariance (VC) matrix of the float solution for ambiguity resolution.

Main Results:

• The PREFMAR method successfully resolves ambiguities without needing a VC matrix.
• The search area is adaptable based on code/phase accuracy and GNSS signal frequencies.
• Numerical examples and real-world tests confirmed instantaneous ambiguity reinitialization capabilities for various baseline lengths.

Conclusions:

• The PREFMAR method provides a precise and fast solution for GPS ambiguity resolution and reinitialization.
• It enables instantaneous reinitialization even after complete loss of satellite contact.
• PREFMAR shows significant potential for enhancing precise real-time kinematic GNSS navigation.