GNSS Receiver Anomaly Detection and Ambiguity Resolution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Global navigation satellite systems face challenges in accurately determining positions due to abnormal measurement errors caused by external influences such as multipath errors, radio interference, and dynamic effects, which can prevent accurate location calculation and require complex computational corrections.
Innovation Solution
A method is introduced that detects and eliminates anomalous measurements prior to complex algorithm execution by calculating single differences, determining a state vector, and using Kalman filters and Householder transformations to resolve integer ambiguities and correct clock offsets, thereby improving measurement accuracy and reducing computational load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex algorithms are used to correct abnormal measurement errors, then measurement accuracy is improved, but computational load increases
Solution Approach 1:
The patent applies preliminary action by detecting and eliminating anomalous measurements before executing complex positioning algorithms. The system performs anomaly detection on raw measurements in advance, removing corrupted data points prior to the main computational process. This prevents the need for complex correction algorithms during positioning calculation, thereby maintaining measurement accuracy while significantly reducing computational load and processing time.
2Reliability
If all measurements are processed to ensure accuracy, then position determination reliability is improved, but processing time increases
Solution Approach 1:
The patent applies the taking out principle by extracting and removing anomalous measurements from the dataset before processing. The system identifies measurements that deviate significantly from expected patterns and eliminates them from further processing. This extraction of bad data ensures that only reliable measurements are used in position determination, maintaining high reliability while reducing the total processing time by excluding problematic data points that would require extensive validation and correction.
3Productivity
If anomaly detection and elimination is performed before algorithm execution, then computational efficiency is improved, but measurement processing complexity increases
Solution Approach 1:
The patent applies preliminary action by performing anomaly detection and elimination in advance before the main positioning algorithms are executed. The system establishes simple statistical criteria for anomaly detection and applies them to filter measurements beforehand. This preliminary filtering step reduces the dataset size and improves computational efficiency for subsequent processing, while the simplicity of the detection criteria keeps the added processing complexity minimal.
Data Source
AI summary
A global navigation system includes a first navigation receiver located in a rover and a second navigation receiver located in a base station. Single differences of measurements of satellite signals received at the two receivers are calculated and compared to single differences derived from an observation model. Anomalous measurements are detected and removed prior to performing computations for determining the output position of the rover and resolving integer ambiguities. Detection criteria are based on the residuals between the calculated and the derived single differences. For resolving integer ambiguities, computations based on Cholesky information Kalman filters and Householder transformations are advantageously applied. Changes in the state of the satellite constellation from one epoch to another are included in the computations.