Radar Sidelobe Suppression via Iterative Signal Subtraction
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Solution Overview
Problem
Radar systems face challenges in distinguishing multiple targets due to the presence of side lobes in target signals, which can overlap and mask weaker signals, making accurate measurement difficult, especially when targets are in close proximity.
Innovation Solution
A method and system that involves generating a composite signal from radar reflections, identifying the largest signal, estimating its parameter value, creating a representative signal as a convolution of a point target, and subtracting it from the composite signal to isolate and detect secondary targets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If digital sampling techniques are used to obtain target signals, then the target signal can be processed and analyzed, but side lobes are generated that can overlap and mask weaker target signals
Solution Approach 1:
The patent extracts and removes the side lobe components from the composite radar signal by identifying the dominant target signal, generating its characteristic waveform, and subtracting it from the composite signal. This isolation process separates the harmful side lobes from the useful target information, allowing weaker targets to be detected without interference.
Solution Approach 2:
The patent performs preliminary signal processing by first identifying the dominant target signal and generating its representative waveform before proceeding with target detection. This preliminary characterization of the strong target's signal structure enables subsequent removal of its side lobes, preparing the signal for better detection of weaker targets.
2Quantity of substance
If multiple targets are detected in close proximity, then comprehensive situational awareness is achieved, but side lobes from stronger targets mask weaker targets making accurate measurement difficult
Solution Approach 1:
The patent segments the composite signal containing multiple targets by iteratively identifying and removing the dominant target signal along with its side lobes. This segmentation process separates overlapping target signals, allowing each target to be measured independently and accurately, thereby enabling detection of multiple targets in close proximity without measurement errors.
Solution Approach 2:
The patent converts the harmful side lobe interference into a beneficial process by using the known structure of the dominant target's side lobes to identify and remove them from the composite signal. This transformation of the interference pattern from a masking element into a recognizable signature enables precise removal and improves the detection of weaker targets.
3Use of energy by moving object
If a strong target signal is present, then strong return signal is received, but its side lobes can mask the presence of weaker target signals
Solution Approach 1:
The patent extracts the side lobe components generated by the strong target signal and removes them from the composite signal. By isolating and eliminating these interfering components, the full information content of weaker target signals is preserved and becomes detectable, preventing information loss that would otherwise occur due to masking.
Data Source
AI summary
A system, method and apparatus for detecting a plurality of targets in a radar device are disclosed. A transmitter transmits a source signal and a receiver receives echo signals from reflection of the source signal from the plurality of targets. A composite signal is generated that includes a plurality of target signals from the plurality of echo signals. A largest signal in the composite signal is identified and a value of a parameter of the largest signal is estimated. A representative signal is generated as a convolution of a point target having the estimated value of the parameter. The representative signal is subtracted from the composite signal to obtain a remaining signal. Another of the plurality of targets is determined using the remaining signal.