Calibrating Group Delay Errors in Combined GPS GLONASS Receivers
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Solution Overview
Problem
Combined GPS and GLONASS receivers face challenges in accurately calibrating group delay errors in GLONASS signals, which can lead to positioning inaccuracies and interference issues, especially in environments with heavy radio frequency interference.
Innovation Solution
A method and system that utilize GPS-based navigation information to estimate and calibrate GLONASS signals by generating a calibration signal with calibration coefficients, processed through an error state Kalman filter, to offset group delay errors in the received GLONASS signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS-based navigation information is used to calibrate GLONASS signals, then measurement precision of GLONASS signals is improved, but device complexity increases due to the need for calibration signal generation and error state Kalman filter processing
Solution Approach 1:
The patent uses GPS-based navigation information as an intermediary to calibrate GLONASS signals. By generating calibration signals from GPS data and using them to correct GLONASS group delay errors, the system achieves high measurement precision without requiring complex direct GLONASS calibration mechanisms
Solution Approach 2:
The error state Kalman filter implements a feedback mechanism that continuously processes calibration signals and adjusts GLONASS signal corrections based on observed errors. This feedback loop maintains measurement precision while managing system complexity through adaptive filtering rather than static complex calibration hardware
2Reliability
If calibration signals are generated and processed through error state Kalman filter, then reliability of navigation information is improved, but loss of time increases due to additional processing steps
Solution Approach 1:
The system generates calibration signals in advance using GPS-based navigation information before they are needed for GLONASS signal correction. This preliminary preparation of calibration data reduces real-time processing requirements and minimizes time loss during critical navigation operations
Solution Approach 2:
The error state Kalman filter continuously processes calibration signals and maintains reliable navigation information without interruption. This continuous processing ensures that reliability is maintained while optimizing time usage by avoiding repeated startup and stopping of calibration operations
3Measurement precision
If group delay errors in GLONASS signals are calibrated using GPS information, then positioning accuracy is improved, but object-affected harmful factors increase due to potential interference between GPS and GLONASS systems
Solution Approach 1:
The patent uses GPS signals as an intermediary to calibrate GLONASS group delay errors, avoiding direct interaction between the two satellite systems. This indirect calibration method achieves high positioning accuracy while minimizing potential radio frequency interference that would occur with direct GLONASS calibration approaches
Data Source
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AI summary
Aspects of a method and system for calibrating group delay errors in a combined GPS and GLONASS receiver are provided. The combined GPS and GLONASS receiver may be enabled to receive both GPS signals and GLONASS signals. GPS based navigation information may be calculated based on the received GPS signals. Group delay errors resulted by the received GLONASS signals may be calibrated based on the GPS based navigation information. Respective GLONASS signals may be estimated in responsive to the GPS based navigation information. Corresponding clock information associated with the estimated GLONASS signals may be transferred from the clock information of the GPS based navigation information. A calibration signal may be generated by comparing the estimated GLONASS signals with the received GLONASS signals. The calibration signal may be processed by an error state Kalman filter and may be used to offset the group delay errors in the combined GPS and GLONASS receiver.