Reference Emitters and Cross-Correlation for Single-Satellite EMI Geolocation
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Solution Overview
Problem
Accurate 3D geolocation of ground-based electromagnetic interference (EMI) sources using a single satellite is challenging due to limited power and clustering environments, necessitating improved methods for Doppler estimation in satellite communication systems.
Innovation Solution
A cross-correlation based method and system for blind EMI Doppler estimation using a single satellite geolocation (SSG) system, involving power spectral density calculation, smoothing, cross-correlation, and ionosphere compensation with enhanced reference emitters to enhance geolocation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If passive geolocation is used with limited satellite power, then energy consumption is reduced, but geolocation accuracy deteriorates
Solution Approach 1:
The patent introduces ionosphere compensation as an intermediary mechanism that corrects signal propagation errors without requiring additional satellite power. By modeling and compensating for ionospheric effects on Doppler measurements, the system maintains high geolocation accuracy while using passive reception only
Solution Approach 2:
The patent transforms the measurement approach by changing from direct signal strength measurement to Doppler frequency shift measurement combined with ionosphere compensation. This parameter transformation enables accurate geolocation using passive reception, resolving the contradiction between low power consumption and high accuracy
2Device complexity
If single satellite geolocation is used, then system complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent changes the measurement parameters from basic signal reception to sophisticated Doppler estimation with ionosphere compensation. By using multiple parameters (Doppler shift, Doppler rate, ionospheric delay) from a single satellite, the system achieves 3D geolocation accuracy comparable to multi-satellite systems while maintaining low complexity
Solution Approach 2:
The patent adds the dimension of ionospheric compensation to the single satellite measurement space, enabling accurate 3D geolocation. By incorporating ionosphere delay compensation into the Doppler estimation process, the system extracts sufficient spatial information from a single satellite's signal
3Loss of time
If Doppler estimation is performed without ionosphere compensation, then processing time is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent performs preliminary ionosphere modeling and compensation calculations before final Doppler estimation. By pre-computing ionospheric delay corrections based on satellite position and signal frequency, the system minimizes real-time processing requirements while maintaining high measurement accuracy
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables precise 3D geolocation of EMI sources, reducing interference and restoring satellite communication operations by improving Doppler estimation accuracy and compensating for ionospheric effects.
Implementation Method 1
blind EMI Doppler estimation from a single satellite geolocation (SSG) system
Implementation Method 2
performing cross correlation between PSD0 and PSD1 to obtain a cross-correlation result; determining a peak position from the cross-correlation result; and obtaining a Doppler estimation based on a peak position shift
Implementation Method 3
smoothing the PSD of the received signal using moving window average
Implementation Method 4
ionosphere compensation with enhanced reference emitters to enhance geolocation accuracy
Data Source
AI summary
The present disclosure provides a cross-correlation based method, a system and a storage medium for blind electromagnetic interference Doppler estimation from a single satellite geolocation system. The method includes at a first time, calculating a power spectral density (PSD) of a received signal; smoothing the PSD of the received signal using moving window average, and saving the smoothed PSD of the received signal as PSD0; at a next time, calculating a PSD of another received signal; smoothing the PSD of the another received signal using moving window average, and saving the smoothed PSD of the another received signal as PSD1; performing cross correlation between PSD0 and PSD1 to obtain a cross-correlation result; determining a peak position from the cross-correlation result; and obtaining a Doppler estimation based on a peak position shift between the peak position and a reference position.