Satellite Positioning Error Removal via Geometric Analysis
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Solution Overview
Problem
Current satellite-based positioning systems, such as GPS, face accuracy issues due to limited coverage of augmentation systems like WAAS and degradation in signal quality, especially in areas with shelters, which affect the reliability of positioning data.
Innovation Solution
The method involves selecting a subset of satellites based on geometric error relations and signal strength variability to improve positioning accuracy by removing satellites that contribute to errors, ensuring a stable and accurate location calculation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If WAAS or AGPS correction services are used to improve positioning accuracy, then positioning accuracy is improved, but coverage area is limited and service reliability deteriorates in sheltered areas
Solution Approach 1:
The patent extracts and removes satellites that form geometric error relations or exhibit abnormal signal strength variations from the positioning calculation. By identifying and excluding these problematic satellites through specific criteria (geometric error relations between satellite vectors, signal strength varied rate thresholds), the system eliminates sources of positioning error without requiring external augmentation services, thereby improving both accuracy and reliability in sheltered areas
Solution Approach 2:
The patent changes the selection parameters for satellite inclusion by introducing dynamic criteria: geometric error relation detection based on satellite vector calculations, and signal strength varied rate monitoring. These parameter changes enable the system to adaptively select optimal satellite subsets, improving positioning accuracy while maintaining service reliability without dependency on WAAS or AGPS coverage
2Reliability
If more satellites are used for positioning calculation, then positioning reliability is improved, but positioning accuracy deteriorates due to geometric error relations
Solution Approach 1:
The patent segments the satellite constellation into two groups: satellites that form geometric error relations (which are excluded) and satellites that do not form such relations (which are used for positioning). By dividing the satellite set based on geometric error analysis of satellite vectors, the system maintains a sufficient number of satellites for reliability while eliminating those that degrade accuracy
Solution Approach 2:
The patent converts the potentially harmful effect of using all available satellites (which may include geometric error-prone satellites) into a benefit by systematically identifying and excluding only those specific satellites that form geometric error relations. This selective exclusion transforms the problem of satellite selection into a solution that improves accuracy while preserving reliability through optimized satellite subset utilization
Data Source
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AI summary
A satellite-based positioning method is applicable in a Global Positioning System (GPS) receiver. The satellite-based positioning method includes the steps of obtaining multiple satellites in use by searching; calculating every satellite vector between each of the satellites in use and the GPS receiver; selecting three of the satellites in use in sequence as a satellite candidate set, searching for one of the satellite candidate set forming a geometric error relation according to the multiple satellite vectors, and using at least one of the satellites in use in the satellite candidate set forming the geometric error relation as a first satellite; searching for at least one second satellite in the satellites in use, wherein a signal strength varied rate of the second satellite is greater than a varied rate threshold; and using the satellites in use having the first satellite or the second satellite removed to perform positioning.