Inter-channel Bias Calibration for Navigation Receivers
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Solution Overview
Problem
Navigation satellite systems, particularly GPS and GLONASS, face significant challenges in achieving centimeter and sub-centimeter accuracy due to inter-channel biases caused by differences in satellite signal frequencies and temperature variations in receiver components, which are not effectively accounted for in current calibration methods.
Innovation Solution
A calibration module generates a reference signal to measure bias delays in the front-end circuitry of navigation receivers, comparing pseudo-noise components to reduce inter-channel biases, using a microprocessor to adjust range and phase corrections and account for varying frequencies and temperature effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If GLONASS satellites transmit on different frequencies, then more satellites can be utilized for positioning, but inter-channel biases are introduced that degrade position accuracy
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the receiver bias compensation based on the actual frequency of each GLONASS satellite signal. Instead of using a fixed bias value, the system varies the compensation parameter according to the specific frequency offset of each satellite, thereby eliminating inter-channel biases and maintaining high position accuracy across multiple frequencies.
2Device complexity
If receiver bias is assumed to be the same for all satellites, then position computations are simplified, but this assumption is violated by GLONASS inter-channel biases
Solution Approach 1:
The patent applies local quality by assigning a unique receiver bias parameter to each GLONASS satellite channel based on its specific frequency. Instead of using a single uniform bias value for all satellites, the system tailors the bias compensation to each individual channel's frequency characteristics, thereby maintaining computational tractability while achieving high precision.
3Ease of operation
If inter-channel biases are not calibrated, then the receiver operation is simpler, but positioning accuracy deteriorates significantly
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing receiver bias values for multiple GLONASS frequencies before actual positioning operations. The system prepares a lookup table or calibration data set that contains frequency-specific bias corrections, allowing the receiver to quickly apply the appropriate correction during operation without complex real-time calculations, thus maintaining both simplicity and accuracy.
Data Source
AI summary
Dynamic inter-channel bias calibration of a navigational receiver is provided. A reference signal is propagated through front-end circuitry of the receiver. A delay caused by the propagation of the reference signal through the front-end circuitry is measured. The inter-channel bias of the navigational receiver is reduced using the measured delay associated with the front-end circuitry of the receiver.