Satellite Navigation Receiver Offset Switching for RTK Outages
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Solution Overview
Problem
Satellite navigation receivers experience abrupt transitions and reduced accuracy when transitioning between real-time kinematic (RTK) and precise positioning modes due to signal interruptions, leading to discontinuities and limited outage tolerance.
Innovation Solution
A satellite navigation receiver and method that enables seamless switching between RTK and precise positioning modes by utilizing an RTK extend module, which includes a quality evaluator, offset module, and mode controller to manage transitions and maintain accuracy during signal outages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the receiver transitions from RTK mode to precise positioning mode due to RTK signal loss, then the receiver can continue providing position estimates, but the transition causes abrupt jumps or discontinuities in position and the accuracy is limited to a maximum time period
Solution Approach 1:
The system performs preliminary actions by determining a precise position solution and calculating an offset between RTK and precise positioning modes while the RTK signal is still available. This offset is stored and applied when transitioning modes, preventing abrupt position jumps and maintaining continuity during signal outages
Solution Approach 2:
The offset calculation acts as an intermediary mechanism that bridges the two positioning modes. By computing the difference between RTK and precise positioning solutions and applying this offset during mode transitions, the system smooths the transition and maintains position continuity without abrupt discontinuities
2Measurement precision
If the receiver operates in RTK mode requiring locally available RTK correction data, then centimeter-level accuracy is achieved, but the mode becomes unavailable when RTK signal is interrupted, corrupted or lost
Solution Approach 1:
The system changes operational parameters by switching between RTK mode and precise positioning mode based on signal availability. When RTK correction data becomes unavailable, the system transitions to precise positioning mode while applying a pre-calculated offset to maintain accuracy, thus adapting to different signal conditions while preserving measurement precision
Solution Approach 2:
The system performs preliminary offset calculation and storage while in RTK mode, so that when the RTK signal is lost, the receiver can immediately transition to precise positioning mode with the pre-computed offset already available, avoiding any loss of accuracy or extended transition time
3Duration of action of moving object
If the receiver provides accuracy consistent with lost RTK mode for a maximum time period, then the receiver can maintain position estimates during short outages, but if RTK signal is not restored within the maximum time period, the receiver must resort to reduced accuracy mode
Solution Approach 1:
The system ensures continuity of useful action by maintaining centimeter-level position accuracy throughout the entire outage period. The pre-calculated offset is applied continuously during precise positioning mode operation, eliminating the need to switch to reduced accuracy modes even during extended outages, thus maintaining both duration and precision
Data Source
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AI summary
A receiver (12 or 30) or method uses an offset vector to provide seamless switching between a real-time kinematic (RTK) mode and a precise positioning mode (e.g., precise point positioning, PPP) mode. An offset module (130) or data processor (159) is arranged to determine an offset between precise position and the RTK position estimate. Upon loss of the RTK signal, switching to a precise position mode is based on a last available RTK position (e.g., if the precise position mode is converged on a position solution with resolved ambiguities of the carrier phase), wherein the next precise position estimate is compensated by the offset or reference frame bias to avoid a jump or discontinuity in the next precise position estimate.