Hybrid Positioning System Clock Bias Refinement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current hybrid positioning systems face challenges in accurately assessing the quality of satellite positioning system (SPS) measurements, leading to inclusion of erroneous range estimates, which affects the precision of location estimation. They struggle to efficiently refine initial estimated locations (IEL) and often rely on time-consuming three-dimensional searches for optimal receiver clock bias variations.
Innovation Solution
The method involves evaluating the quality of SPS measurements by analyzing receiver clock bias variations across a region, rejecting satellites with large variations, and using two-dimensional searches to quickly identify locations with minimal clock bias variations, thereby refining the initial location estimate and improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If three-dimensional searches are used to find optimal receiver clock bias variations, then location estimation accuracy is improved, but processing time increases significantly
Solution Approach 1:
The patent segments the three-dimensional search space into multiple two-dimensional planes (e.g., XY plane, XZ plane, YZ plane). Instead of performing a single exhaustive 3D search, the system performs separate 2D searches on each plane to find optimal receiver clock bias variations, significantly reducing computational complexity while maintaining accuracy.
Solution Approach 2:
The patent transforms the three-dimensional search problem into multiple two-dimensional search problems. By projecting the 3D search space onto 2D planes and performing searches in these reduced dimensions, the system achieves faster processing while still capturing the essential variations in receiver clock bias across the search space.
2Adaptability or versatility
If all satellite measurements are included in hybrid positioning, then coverage is maintained, but measurement precision deteriorates due to erroneous range estimates
Solution Approach 1:
The patent applies local quality by evaluating and selecting satellites based on their individual measurement qualities. Instead of uniformly including all satellites, the system assesses each satellite's range estimate quality and selectively incorporates only those with acceptable precision, allowing high-quality measurements to dominate while maintaining overall system functionality.
Solution Approach 2:
The patent implements feedback mechanisms where the system continuously evaluates satellite measurement qualities and adjusts which satellites are included in positioning calculations. By monitoring measurement precision and providing feedback on quality metrics, the system dynamically selects optimal satellite subsets, excluding erroneous measurements while maintaining coverage.
Data Source
AI summary
The present disclosure relates to a method for determining the position of a WLAN positioning system (WPS) and satellite positioning system (SPS) enabled device. The method can include determining an initial WPS position of the device using WPS, calculating an error region around the initial WPS position of the device, dividing the error region into a plurality of points, obtaining satellite measurements from at least two satellites in view of the device, determining a variation in a receiver clock bias for each point within the error region based on the satellite measurements from at least two satellites, selecting the point with the lowest variation in the receiver clock bias, and determining whether or not to use the point with the lowest variation in receiver clock bias to refine the initial WPS position of the device.