Geopositioning Assistance Data for Single-Frequency Phase Ambiguity Resolution
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Solution Overview
Problem
Current satellite positioning systems face challenges in resolving phase ambiguities without multi-frequency observations, limiting the accuracy of geopositioning, especially for single-frequency receivers.
Innovation Solution
A method using a network of reference receivers to determine assistance data that allows single-frequency receivers to resolve phase ambiguities by calculating iono-free transmitter and receiver clock values, which are then used to derive unambiguous carrier code shift observables, enabling precise geopositioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If single-frequency receivers are used for geopositioning, then device complexity is reduced, but measurement precision deteriorates due to unresolved phase ambiguities
Solution Approach 1:
The invention applies preliminary action by pre-calculating and storing iono-free transmitter clock values and measurement residues from a network of reference receivers before the user receiver needs them. These pre-computed assistance data are then transmitted to and used by single-frequency receivers to resolve phase ambiguities, enabling high-precision geopositioning without requiring the receiver to perform complex real-time calculations or use multiple frequencies.
2Measurement precision
If phase measurements are used for geopositioning, then measurement precision is improved, but reliability deteriorates due to phase ambiguities
Solution Approach 1:
The invention uses an intermediary approach by introducing a network of reference receivers as mediators between the satellite signals and the user receiver. These reference receivers compute assistance data that acts as an intermediary product, containing resolved phase ambiguity information that the user receiver can directly utilize. This intermediary layer enables single-frequency receivers to achieve reliable phase ambiguity resolution without needing to implement complex resolution algorithms themselves.
3Measurement precision
If multi-frequency observations are used to resolve phase ambiguities, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The invention applies the extraction principle by separating the complex task of phase ambiguity resolution from the user receiver. Instead of requiring the user receiver to perform multi-frequency observations and complex resolution algorithms, the invention extracts and pre-computes the essential assistance data (iono-free transmitter clock values and measurement residues) at reference receiver stations. This extracted assistance data is then provided to single-frequency receivers, eliminating the need for them to implement multi-frequency processing while still achieving high-precision results.
Data Source
AI summary
A method for determining assistance data to facilitate processing of radio-navigation signals from a set of radio-navigational satellites of a reference network, each radio-navigational satellite broadcasting at least a first radio-navigation signal on a first frequency and a second radio-navigation signal on a second frequency, the second frequency being distinct from the first frequency, is provided.