Static GNSS Positioning Using Accumulated Pseudorange Differences
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Solution Overview
Problem
GNSS receivers in challenging signal environments, such as indoor or urban settings, face difficulties in accurately estimating their position due to limited and poor-quality GNSS signals, leading to inaccurate timing data.
Innovation Solution
A method for estimating the position of a static GNSS receiver by calculating differences between pseudoranges from GNSS satellites observed at different times, allowing for position estimation even with intermittent and low-quality signals, and a static GNSS receiver configured to perform this method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional GNSS positioning techniques requiring simultaneous measurements from at least four satellites are used, then position calculation accuracy is improved under ideal conditions, but the system becomes unreliable in challenging signal environments with limited satellite visibility
Solution Approach 1:
The system performs preliminary actions by accumulating pseudorange difference measurements over multiple time epochs before calculating the final position. The receiver stores difference measurements from multiple satellites observed at different times, allowing the position to be calculated from accumulated data rather than requiring simultaneous four-satellite visibility. This preliminary accumulation of measurements enables reliable position estimation even when simultaneous satellite visibility is limited.
2Adaptability or versatility
If GNSS receivers are mounted in challenging signal environments such as indoors or urban areas to provide full cellular coverage, then network coverage is improved, but signal quality and positioning accuracy deteriorate
Solution Approach 1:
The receiver performs preliminary accumulation of pseudorange difference measurements from multiple time epochs, storing them in memory before calculating position. This allows the system to aggregate sufficient measurement data even from limited simultaneous satellite observations, enabling accurate position estimation in indoor and urban environments where traditional simultaneous four-satellite requirements cannot be met.
Solution Approach 2:
The system transitions from requiring simultaneous measurements in a single time epoch to utilizing measurements across multiple time epochs. By accumulating difference measurements over time and using the temporal dimension to supplement spatial satellite geometry, the system achieves reliable positioning in environments with limited satellite visibility.
3Reliability
If the receiver accumulates pseudorange differences from multiple time epochs, then positioning capability in challenging environments is improved, but computational complexity and data processing requirements increase
Solution Approach 1:
The system segments the positioning calculation process into distinct steps: (1) measuring pseudoranges from multiple satellites at multiple time epochs, (2) calculating pseudorange differences for each satellite pair at each epoch, (3) accumulating these difference measurements in memory, and (4) performing the final position calculation from the accumulated differences. This segmentation allows complex data to be processed in manageable stages and stored efficiently.
Solution Approach 2:
The receiver performs preliminary processing by calculating and storing pseudorange difference measurements from multiple time epochs before the final position calculation. This preliminary accumulation of difference data reduces the computational burden during the actual positioning calculation, as the system only needs to process accumulated differences rather than raw pseudorange measurements from multiple satellites across multiple times.
Data Source
AI summary
A static GNSS receiver, a base station module, a method of estimating a position of a static GNSS receiver, and an associated computer program are provided. An example method includes calculating a first difference between a first pseudorange and a second pseudorange, each made at a first time. A second difference between a third pseudorange and a fourth pseudorange, each made at a second time, is calculated, with the second time different to the first time. A position of the GNSS receiver is calculated based at least in part on the accumulated pseudorange differences.