GNSS Differential Code Bias Correction With Limited Reference Stations
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Solution Overview
Problem
Existing methods for providing differential code bias (DCB) corrections in global navigation satellite systems (GNSS) are inefficient when limited reference stations are available, leading to unreliable calculations for signals that cannot be freely measured, particularly affecting the accuracy of positioning applications.
Innovation Solution
A method that determines primary differential code biases for a first and second signal on the same carrier frequency, using these to calculate secondary differential code biases for additional signals, thereby reducing the need for isolated calculations and improving accuracy without relying on a dense reference station network.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If DCBs are estimated separately for each signal combination using limited reference stations, then signal-specific accuracy is maintained, but the number of reference stations required increases system complexity and cost
Solution Approach 1:
The DCB estimation problem is segmented into two parts: a common DCB component that is shared across all signal combinations, and a signal-specific DCB component that is estimated separately for each signal combination. This segmentation allows the system to reduce the number of reference stations while maintaining estimation accuracy for specific signals.
Solution Approach 2:
The patent changes the parameter representation of DCBs by introducing a common DCB parameter that is shared across multiple signal combinations. This parameter change allows information to be transferred between different signal combinations, reducing the total number of independent parameters that need to be estimated and thereby reducing the reference station network complexity.
2Device complexity
If the number of reference stations is reduced for non-public signals, then system complexity is reduced, but DCB estimation reliability deteriorates
Solution Approach 1:
The common DCB component acts as an intermediary that transfers information between different signal combinations. By estimating the common DCB from multiple signal combinations using a reduced number of reference stations, the system maintains reliability for non-public signals even with fewer reference stations available.
Solution Approach 2:
The common DCB estimation serves multiple functions: it provides the baseline DCB for all signal combinations and enables the estimation of signal-specific DCBs even when reference station data is limited. This multi-functionality allows the system to maintain reliability across different signal types with reduced infrastructure.
3Measurement precision
If separate DCB estimation is performed for each signal combination, then signal-specific accuracy is maintained, but processing time and computational resources increase
Solution Approach 1:
The common DCB is estimated first as a preliminary step before estimating the signal-specific DCBs. This preliminary estimation provides a solid baseline that reduces the computational burden and time required for the subsequent signal-specific estimations, as the system starts with already-processed common information rather than processing each signal combination from scratch.
Data Source
AI summary
A method for providing a differential code bias, in particular a primary differential code bias and a secondary differential code bias, in a global navigation satellite system using satellites communicating by using at least a first signal and an additional first signal both having a first carrier frequency and a second signal and an additional second signal both having a second carrier frequency, where a primary differential code bias for the first signal and the second signal is determined and wherein the primary differential code bias is used for determining, and in particular providing, a secondary differential code bias for the additional first signal and the additional second signal.