GNSS Ambiguity Resolution Using Multi-Engine Search
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current GNSS ambiguity resolution algorithms, such as the LAMBDA method, face challenges in ensuring successful ambiguity resolution due to poor geometry of satellites, leading to longer processing times and lower accuracy, especially in scenarios with poor satellite visibility and varying measurement quality.
Innovation Solution
The implementation of a multi-engine search technique and adaptive residual threshold setting, which allows for parallel processing and dynamic adjustment of search spaces based on measurement errors and scenario parameters, to efficiently identify and eliminate incorrect candidates and improve the ambiguity resolution process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the LAMBDA algorithm is used for ambiguity resolution, then the processing can be performed in a single instantaneous search epoch, but the algorithm cannot provide assurance of successful ambiguity resolution and may fail due to poor satellite geometry
Solution Approach 1:
The patent divides the ambiguity resolution process into multiple independent searching engines, each responsible for a specific subset of candidate solutions. This segmentation allows parallel processing while maintaining comprehensive search coverage, resolving the contradiction between fast processing and reliable resolution by distributing the search workload across multiple engines that operate simultaneously
Solution Approach 2:
The patent performs preliminary actions by pre-calculating and storing candidate solutions in a database before the actual positioning operation. This preliminary preparation allows the system to quickly retrieve and evaluate candidates during real-time processing, improving both speed and reliability by having pre-computed options ready for immediate use
2Loss of time
If the LAMBDA algorithm performs instantaneous search, then the processing time is reduced, but the accuracy and reliability of ambiguity resolution deteriorate due to insufficient search thoroughness
Solution Approach 1:
The patent implements periodic action by executing multiple search epochs in sequence, where each epoch performs a complete search through candidate solutions. This periodic repetition allows the system to thoroughly evaluate all possibilities multiple times, ensuring high accuracy while managing processing time through efficient epoch management and early termination when sufficient precision is achieved
Solution Approach 2:
The patent applies dynamics by making the search process adaptive and flexible, allowing the number of epochs and search depth to vary based on the specific measurement conditions and satellite geometry. This dynamic adjustment enables the system to allocate processing time efficiently, spending more time when needed for high accuracy and less time when rapid processing is sufficient
3Measurement precision
If redundant satellites are used to improve positioning accuracy, then the measurement precision improves, but the device complexity increases due to additional processing requirements
Solution Approach 1:
The patent segments the complex processing task by dividing redundant satellite data into manageable groups and assigning specific searching engines to process specific subsets. This segmentation reduces the complexity of individual processing units while maintaining the benefits of using redundant satellites for improved accuracy through distributed computation
Solution Approach 2:
The patent introduces intermediary structures such as candidate solution databases and standardized evaluation protocols that mediate between the raw redundant satellite measurements and the final positioning results. These intermediaries simplify the processing by providing structured frameworks for handling and evaluating redundant data, reducing overall algorithmic complexity
Data Source
AI summary
Systems and methods for GNSS ambiguity resolution are described herein. In some examples, the systems and methods utilize multiple search engines in parallel to validate potential integer candidates for ambiguity resolution using adaptively adjusted residual thresholds.