NeQuick-G Ionosphere Estimation with Real-Time Local cUKF Updates
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Solution Overview
Problem
Existing ionospheric correction models, such as NeQuick-G, are not optimized for local users and lack real-time updates, leading to suboptimal performance in geolocation and interference mitigation due to nonhomogeneous electron densities and magnetic fields in the ionosphere.
Innovation Solution
Implementing a constrained unscented Kalman filter (cUKF) to update the NeQuick-G model using ionospheric coefficients estimated from multiple enhanced reference emitters and a low earth orbit satellite, enabling real-time and locally optimized ionosphere estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If NeQuick-G model is used with standard ionospheric coefficients, then the model provides global coverage, but the coefficients are not optimized for local users and cannot be updated in real-time
Solution Approach 1:
The patent applies local quality by transitioning from global ionospheric coefficients to locally optimized coefficients. The system estimates local ionospheric parameters (Kp index, solar flux, geomagnetic activity) specific to each user's geographic location and updates the NeQuick-G model coefficients accordingly. This enables the model to provide accurate ionosphere estimation tailored to local conditions rather than using generic global coefficients.
Solution Approach 2:
The patent implements dynamics by enabling real-time updates of ionospheric coefficients. Instead of using static coefficients transmitted by Galileo satellites, the system continuously monitors ionospheric conditions and dynamically adjusts the NeQuick-G model coefficients based on current local measurements. This dynamic updating capability allows the model to adapt to changing ionospheric conditions in real-time.
2Productivity
If NeQuick-G model uses standard coefficients transmitted by Galileo satellites, then the model is accessible globally, but the coefficient updates are not in real-time
Solution Approach 1:
The patent applies feedback by implementing a real-time monitoring and updating mechanism. The system continuously monitors local ionospheric conditions and uses this feedback to adjust the NeQuick-G model coefficients immediately. This feedback loop eliminates the time delay inherent in satellite-transmitted coefficients, allowing the model to respond to current ionospheric conditions without waiting for periodic satellite updates.
3Measurement precision
If ionospheric correction models are used to mitigate ionospheric delay, then positioning accuracy improves, but the models cannot account for nonhomogeneous electron densities and magnetic fields
Solution Approach 1:
The patent addresses nonhomogeneous electron densities and magnetic fields by implementing local quality through geographic-specific modeling. The system divides the ionosphere into local regions and estimates ionospheric parameters separately for each location. This allows the model to account for local variations in electron density and magnetic field conditions rather than using a uniform global model, thereby improving positioning accuracy in diverse ionospheric environments.
Data Source
AI summary
The present disclosure provides an ionosphere estimation method applied to a single satellite, an ionosphere estimation system, and a storage medium. The method includes providing locations of the single satellite and an enhanced reference emitter (ERE); using the locations of the single satellite and the ERE to obtain a measured ionospheric delay and transmitting the measured ionospheric delay to the ERE; determining a measured STEC using the measured ionospheric delay; and updating a NeQuick-G model deployed in one or more of the plurality of EREs by implementing a cUKF. Updating the NeQuick-G model includes inputting a plurality of ionospheric coefficients estimated by cUKF to the NeQuick-G model; calculating an effective ionization level using the plurality of ionospheric coefficients; using the effective ionization level to obtain an estimated STEC; calculating updated ionospheric coefficients using the estimated STEC and the measured STEC; and updating the NeQuick-G model using the updated ionospheric coefficients.