Carrier Phase Ambiguity Search Constrained by Terrestrial Spatial Data
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing satellite positioning systems face challenges in resolving integer ambiguities in carrier phase measurements, particularly in non-open-sky environments, leading to inefficiencies in high-precision positioning and satellite signal acquisition.
Innovation Solution
Constraining the satellite positioning system carrier phase integer ambiguity search space using spatial information from terrestrial-based signals, such as range, angle, and position estimates, to reduce the search space and enhance precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the satellite positioning system uses carrier phase measurements for high-precision positioning, then positioning precision is improved, but the integer ambiguity search space becomes excessively large making resolution difficult
Solution Approach 1:
The patent segments the integer ambiguity resolution problem by dividing the search space into manageable subsets using spatial constraints. Instead of searching the entire ambiguous space, the system partitions it based on geometric relationships between satellites, improving tractability while maintaining precision.
Solution Approach 2:
The patent applies local quality by focusing the search effort on specific regions of the ambiguity space that are most likely to contain the correct integer solution. By identifying and concentrating computational resources on promising local areas rather than uniformly searching all possibilities, the system achieves efficient resolution.
2Measurement precision
If the system searches the full integer ambiguity space to ensure accurate positioning, then positioning accuracy is maintained, but the time required for signal acquisition and positioning increases
Solution Approach 1:
The patent performs preliminary actions by pre-computing spatial constraints and geometric relationships before the actual integer ambiguity resolution. By preparing constraint information in advance based on satellite ephemeris and receiver position data, the system reduces the computational burden during real-time positioning, enabling faster acquisition without sacrificing accuracy.
Solution Approach 2:
The patent applies partial action by searching only a constrained subset of the full ambiguity space rather than exhaustively searching all possibilities. The spatial constraints eliminate obviously incorrect solutions, allowing the system to achieve sufficient accuracy by examining only the most promising candidates.
3Adaptability or versatility
If the system operates in non-open-sky environments with limited satellite visibility, then coverage is maintained, but the integer ambiguity resolution becomes more challenging due to reduced geometric diversity
Solution Approach 1:
The patent introduces spatial dimensionality constraints as an additional degree of freedom for resolving ambiguities. By incorporating three-dimensional geometric relationships between satellites and the receiver, the system compensates for reduced satellite visibility in non-open-sky environments, maintaining reliability through enhanced geometric modeling.
Data Source
AI summary
A method of determining an integer ambiguity search space includes: obtaining, at an apparatus, a code phase measurement of a satellite vehicle signal comprising a pseudorandom noise code and a carrier signal; obtaining, at the apparatus, spatial information corresponding to a wireless terrestrial signal transferred between the apparatus and a terrestrial base station; determining, at the apparatus, a satellite positioning system carrier phase integer ambiguity search space based on the code phase measurement; and constraining a size of the satellite positioning system carrier phase integer ambiguity search space based on the spatial information.