GNSS Position Processor Resolving Carrier Phase Ambiguity
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Solution Overview
Problem
Current Global Navigation Satellite Systems (GNSS) face challenges in quickly and accurately estimating integer phase ambiguities for precise real-time positioning, especially in applications like fast-moving vehicles and unmanned aerial vehicles, due to the high regularity of carrier phase measurements leading to ambiguities in phase alignment.
Innovation Solution
A system that includes a position processor with an unconstrained localization calculator, an integer-constrained phase calculator, and a baseline coordinate re-estimator, which uses integer quadratic minimization with bootstrapping and truncated Gaussian sampling to determine the most likely integer solution for carrier phase ambiguities from GNSS code and carrier phase measurements, enabling rapid and accurate position estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If carrier phase measurements are used for positioning, then positioning accuracy is improved, but phase alignment ambiguities worsen
Solution Approach 1:
The patent uses code phase measurements as an intermediary to resolve carrier phase ambiguities. The code phase measurements, which have lower precision but no ambiguity, serve as a reference to determine the correct integer cycle alignment for the carrier phase measurements, thereby eliminating the phase alignment ambiguity while maintaining high positioning accuracy.
Solution Approach 2:
The patent transforms carrier phase measurements into accurate pseudo-range measurements by resolving the integer cycle ambiguities. This parameter transformation converts the ambiguous carrier phase data into unambiguous positioning information that can be directly used for accurate position calculation.
2Productivity
If integer phase ambiguity estimation is performed quickly, then real-time positioning is improved, but estimation accuracy may worsen
Solution Approach 1:
The patent performs preliminary estimation of integer phase ambiguities using code phase measurements before refining the solution with carrier phase measurements. This preliminary action provides an initial estimate that guides the subsequent accurate resolution process, enabling both rapid and accurate ambiguity estimation in real-time.
Solution Approach 2:
The patent employs an iterative feedback process where initial ambiguity estimates are refined through multiple processing steps. The system continuously adjusts the ambiguity estimates based on feedback from both code and carrier phase measurements, improving accuracy while maintaining real-time performance through efficient feedback loops.
Data Source
AI summary
A system for rapid determination of an unknown position includes an interface and a processor. The interface is configured to receive carrier phase information and code information from a global navigation satellite system signal. The processor is configured to receive double-difference phase information generated using carrier phase information and code information; and calculate an accurate position based at least in part on a most likely integer solution for the carrier phase ambiguity based at least in part on the double-difference phase information.