GNSS Positioning Correction Using Satellite Geometry and Sky Blocking Curves
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Solution Overview
Problem
In urban scenarios with densely distributed high-rise buildings, satellite signals are often blocked, leading to significant measurement errors in pseudoranges, which severely affect the positioning accuracy of electronic devices using GNSS systems.
Innovation Solution
A positioning method that involves a first electronic device determining a second electronic device's location by selecting candidate locations based on elevations and azimuths of satellites relative to these locations, using grid data that includes sky blocking curves to assess signal blocking status, and correcting the location to improve accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If GNSS positioning is used in urban scenarios with densely distributed high-rise buildings, then positioning can be provided, but signal blocking causes large pseudorange measurement errors that severely affect positioning accuracy
Solution Approach 1:
The system performs preliminary actions by pre-obtaining elevation and azimuth information of satellites relative to candidate locations, and pre-acquiring grid data including sky blocking curves. This preparatory work enables the system to assess signal blocking status before actual positioning, allowing it to identify and correct for potential signal reflection issues caused by high-rise buildings, thereby maintaining positioning accuracy in urban environments
Solution Approach 2:
The system introduces an intermediary assessment mechanism that uses sky blocking curves and signal parameter analysis to evaluate the reliability of pseudorange measurements. This intermediary layer acts as a filter between the raw GNSS signals and the final positioning result, identifying cases where signals are reflected by buildings and correcting these measurements, thus resolving the contradiction between maintaining positioning availability and ensuring measurement precision
2Reliability
If broadcast signals are received after reflection by obstructions, then signal reception is possible in blocked scenarios, but pseudorange measurement errors increase significantly
Solution Approach 1:
The system implements feedback by analyzing signal parameters and comparing them against expected values based on sky blocking curves and satellite geometry. When reflections are detected through this feedback mechanism, the system can identify the discrepancy between the measured pseudorange and the true geometric distance, then apply corrections to eliminate the measurement error while preserving the ability to use reflected signals for positioning
Solution Approach 2:
The system changes parameters by incorporating elevation and azimuth angles of satellites relative to candidate locations, along with sky blocking curve data, into the positioning calculation process. These parameter changes enable the system to distinguish between direct-line-of-sight signals and reflected signals, and to apply appropriate corrections to reflected signal measurements, thereby maintaining pseudorange accuracy even when signal reception relies on reflections
Data Source
AI summary
This application provide a positioning method, including: obtaining, by a first electronic device, a first location of a second electronic device; determining a plurality of candidate locations by using the first location as a reference point; selecting a plurality of candidate positioning locations from the plurality of candidate locations based on elevations and azimuths of a plurality of satellites relative to the candidate locations, grid data corresponding to the plurality of candidate locations, and signal parameters of broadcast signals received by the second electronic device from the plurality of satellites; and correcting the first location based on the plurality of candidate positioning locations, to output a corrected second location.