Single-Antenna Radar Pulse Analysis for Relative Velocity and AOA
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Solution Overview
Problem
Existing direction finding systems face challenges due to size and weight constraints that preclude the use of multiple antennas, and synthetic aperture radars require knowledge of transmitted signal characteristics, which may not always be available.
Innovation Solution
A single-antenna system estimates relative velocity and angle of arrival (AOA) using pulse measurement and phase analysis of pulsed continuous wave radar signals, calculating relative velocity based on time and phase differences, and AOA based on the ratio of relative velocity to receiver platform velocity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple antennas are used for direction finding, then direction finding accuracy is improved, but device weight and size increase
Solution Approach 1:
The patent replaces mechanical antenna arrays with a single antenna combined with signal processing techniques. Specifically, it uses Doppler frequency shift analysis and time of arrival measurements from a single antenna to determine direction finding information, substituting the mechanical/physical array structure with electronic signal processing methods.
Solution Approach 2:
The patent changes the measurement parameters from spatial sampling (multiple antenna positions) to temporal and frequency domain sampling (time of arrival and Doppler shift measurements). By measuring the Doppler frequency shift caused by relative motion and the time of arrival differences, the system achieves direction finding capability with a single antenna.
2Measurement precision
If synthetic aperture radar is used for direction finding, then direction finding capability is improved, but knowledge of transmitted signal characteristics is required
Solution Approach 1:
The system uses the received signal itself to extract direction finding information without requiring external knowledge of the transmitted signal characteristics. By analyzing the Doppler frequency shift and time of arrival of the received signal, the system self-determines the necessary parameters for direction finding independently of the transmitted signal's original characteristics.
Solution Approach 2:
The patent replaces the synthetic aperture radar approach (which requires knowledge of transmitted signal characteristics) with a method based on passive signal analysis. The system measures Doppler shifts and time of arrival directly from received signals, substituting the active SAR methodology with passive observational techniques that do not require prior knowledge of transmitted signals.
3Measurement precision
If mechanical antenna steering is used for direction finding, then direction finding accuracy is improved, but system complexity and mechanical reliability decrease
Solution Approach 1:
The patent eliminates mechanical antenna steering by using signal processing methods. Instead of physically moving the antenna to scan for signals, the system processes signals received by a stationary single antenna using Doppler frequency analysis and time of arrival measurements, completely replacing mechanical steering with electronic processing.
Solution Approach 2:
The system utilizes the periodic nature of the received radar signals and the periodic Doppler frequency shifts that occur during relative motion between transmitter and receiver. By analyzing these periodic variations in frequency and time of arrival, the system extracts direction finding information without mechanical movement.
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 improved EW situational awareness for threat warning, evasion, and targeting by estimating relative velocity and AOA without mechanical steering or knowledge of transmitted signal characteristics.
Implementation Method 1
a pulse measurement circuit configured to measure a first time of arrival, a first phase, and a frequency of a first received radar pulse
Implementation Method 2
a pulse measurement circuit configured to measure a first time of arrival, a first phase, and a frequency of a first received radar pulse
Implementation Method 3
calculating relative velocity based on time and phase differences, and AOA based on the ratio of relative velocity to receiver platform velocity
Data Source
AI summary
Techniques are provided for estimation of relative velocity between a receiver platform and a transmitter platform. A methodology implementing the techniques according to an embodiment includes measuring a first time of arrival, a first phase, and a frequency of a first radar pulse received from the transmitter platform. The method also includes measuring a second time of arrival and a second phase of a second radar pulse received from the transmitter platform. The method further includes calculating a relative velocity between the receiver platform and the transmitter platform based on a difference between the first time of arrival and the second time of arrival, a difference between the first phase and the second phase, and the frequency. The method further includes calculating an angle of arrival of the first and second received radar pulses based on a ratio of the calculated relative velocity to a velocity of the receiver platform.