Dispersive Target Identification via Frequency Agile Waveforms
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Solution Overview
Problem
Current detection methods are inadequate for identifying dispersive targets, such as indirect fire weapons and barreled systems, due to limitations in distinguishing between dispersive and non-dispersive targets, especially in the presence of clutter and varying frequency responses.
Innovation Solution
A dispersive target identification apparatus employing frequency agile signal waveforms, phase shifting, and probability modules to differentiate between dispersive and non-dispersive targets by analyzing the frequency-dependent returns from radar pulses, utilizing stepped-frequency coherent radar and Moving Target Indicator techniques for clutter rejection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional radar detection methods are used, then detection of stationary targets is possible, but dispersive targets cannot be effectively distinguished from clutter
Solution Approach 1:
The patent transmits radar signals at multiple different frequencies and analyzes frequency-dependent phase shifts in the returned signals. By changing the frequency parameter and measuring how the target's response varies with frequency, the system can identify dispersive targets (like barreled weapons) that exhibit characteristic phase shift patterns across frequencies, distinguishing them from non-dispersive clutter.
Solution Approach 2:
The patent uses phase shift measurements as an intermediary parameter to indirectly identify dispersive targets. Instead of directly detecting target properties, the system measures phase shifts at multiple frequencies and uses these measurements as intermediate data to infer the presence of dispersive targets through pattern recognition and probability analysis.
2Measurement precision
If frequency agile signal waveforms are used to detect dispersive targets, then target discrimination capability is improved, but signal processing complexity increases
Solution Approach 1:
The patent segments the frequency spectrum into multiple discrete frequency steps and processes the returned signal at each frequency separately. By dividing the broad frequency sweep into manageable segments and analyzing phase shifts at each step, the system achieves accurate dispersive target identification while keeping the processing complexity at each stage manageable through systematic organization.
3Object-affected harmful factors
If stepped-frequency coherent radar is used with Moving Target Indicator techniques, then clutter rejection is enhanced, but detection of stationary dispersive targets becomes more challenging
Solution Approach 1:
The patent inverts the conventional MTI approach by not filtering out stationary returns, but rather by exploiting the frequency-dependent phase shift characteristics that stationary dispersive targets exhibit. Instead of removing stationary signals as clutter, the system uses their unique dispersive signature across frequencies as the detection criterion, turning what was traditionally considered a limitation into a detection advantage.
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
Effectively detects and identifies dispersive targets by exploiting frequency-dependent shifts and Doppler effects, enhancing signal-to-clutter ratios and enabling accurate discrimination from non-dispersive clutter and stationary targets.
Implementation Method 1
A first dispersive target return and a second dispersive target return are received from transmission of a first frequency agile signal waveform and a second frequency agile signal waveform, respectively, toward the dispersive target. The returns are processed to determine a probability of the dispersive target when the combined return signal exceeds a threshold.
Data Source
AI summary
A first frequency agile waveform and additional frequency agile signal waveform(s) having in-phase and a quadrature phase components, each shifted by a different delta frequency, are transmitted in the direction of a possible dispersive target. Return signal(s) each comprising an in-phase component and a quadrature phase component associated with each of the frequency agile waveform(s) are received. The return signal(s) associated with the frequency agile signal waveform(s) are phase shifted by their respective delta frequenc(ies). A combined return signal is generated by combining the first return signal and the additional phase shifted return signal(s). A probability of a potential target is determined when the combined return signal exceeds a threshold.