Transient Satellite Doppler Processing for Spoof-Resistant Positioning
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Solution Overview
Problem
Existing GPS systems are susceptible to spoofing and service denial, and atmospheric conditions cause significant RF signal refraction errors, leading to inaccurate location determination.
Innovation Solution
A system utilizing transient satellite Doppler signal processing with a multi-channel receiver, antenna, and internal clock to passively measure satellite signals, determine orbital characteristics, and triangulate position using Doppler calculations, leveraging any known satellite constellation without decoding data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If GPS systems are used for location determination, then location data can be obtained, but the system is susceptible to spoofing and service denial attacks
Solution Approach 1:
The patent converts the harmful Doppler effect caused by satellite motion into a beneficial feature for identification. By measuring and analyzing the Doppler shift in satellite signals, the system creates a unique fingerprint for each satellite that enables positive identification and authentication, thereby converting a potential source of error into a security and reliability mechanism against spoofing attacks
Solution Approach 2:
The patent replaces the GPS dependency on coded data messages with a physics-based method using Doppler frequency analysis. Instead of relying on cryptographic authentication of GPS signals that can be spoofed, the system uses fundamental physical principles (Doppler effect) to independently verify satellite identity and calculate position, creating a spoof-proof location determination system
2Measurement precision
If GPS uses two separate frequencies to minimize propagation speed error, then atmospheric refraction error is reduced, but the system complexity and cost increase
Solution Approach 1:
The patent extracts and utilizes the Doppler frequency information already present in single-frequency satellite signals. By taking out and analyzing the Doppler shift component separately, the system achieves precise location determination without needing multiple frequencies, simplifying the receiver design while maintaining or improving accuracy
Solution Approach 2:
The system uses the satellite's own motion-induced Doppler effect as the measurement basis. The Doppler shift naturally encodes both the satellite's orbital characteristics and the receiver's position information, allowing the system to self-determine location using a single frequency without requiring additional frequency resources or complex atmospheric correction models
3Measurement precision
If ground stations or dedicated signals are used to enhance GPS performance, then location accuracy is improved, but significant additional expense and operational capacity are required
Solution Approach 1:
The patent enables each receiver to independently determine its location using only signals from satellites and basic Doppler analysis. The system performs all necessary calculations locally using the receiver's internal clock and processor, eliminating the need for ground-based augmentation infrastructure while achieving high precision through the physics-based Doppler measurement method
4Measurement precision
If transient satellite Doppler signal processing is used, then spoof-proof location determination with centimeter-level precision is achieved, but the processing complexity increases
Solution Approach 1:
The system performs preliminary identification of satellites based on Doppler characteristics before proceeding to position calculation. By pre-processing and filtering satellite signals based on their Doppler fingerprints, the system reduces the computational burden of subsequent position determination while maintaining centimeter-level precision
Solution Approach 2:
The patent focuses on processing only the essential Doppler frequency information from satellite signals rather than analyzing all signal components. By concentrating computational resources on the critical Doppler shift measurement and identification, the system achieves high precision location determination with manageable processing complexity
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
Provides accurate and spoof-proof location determination with centimeter-level precision, resistant to interference and atmospheric errors, using passive signal reception and physics-based methods.
Implementation Method 1
an antenna positioned at a point of interest and configured to measure a received electromagnetic radiation (EMR) signal
Implementation Method 2
determine a first orbital characteristic of the first satellite from the first measured signal responsive to an indication of the current time via a first doppler calculation
Implementation Method 3
the troposphere and ionosphere can change the speed of propagation of a GPS signal. Due to atmospheric conditions, the atmosphere refracts the satellite signals as they pass through on their way to the earth's surface
Data Source
AI summary
A system and method for transient satellite doppler signal position determination to receive measured signals associated with respective satellites, determine transmission characteristics from the measured signals, determine orbital characteristics of the satellites from the measured signals responsive to indications of the current time via Doppler calculations, identify the satellites responsive to the transmission characteristics and/or and the orbital characteristics, determine a current position of the satellites relative to the system from the Doppler calculations and identifying the satellites, and determine a geolocation of the system responsive to the current position of the satellites relative to the system.