Radar Cross Section Measurement Using Deconvolution Under RFI

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Measuring the radar cross section of low radar-signature targets is challenging due to increasing radio frequency interference (RFI) from sources like mobile phones, TV, satellites, and other radars, which conventional methods like using larger amplifiers and higher power signals can disrupt other transmissions.

Innovation Solution

Employing time-gating techniques and post-processing software to 'walk' radar pulses along a test range with low RFI, using a sequence of pulses at a fixed frequency, and applying deconvolution methods with regularisation constants to mitigate RFI effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional measurement techniques (such as the bistatic radar equation) are used to determine radar cross sections, then measurements can be performed with existing equipment, but the measurements require precise knowledge of antenna gain patterns and are sensitive to errors in gain determination

Engineering Contradiction:
Improveradar cross section measurement precisionVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a calibration target with known radar cross section as an intermediary reference object. By measuring the calibration target first and using its known properties, the system establishes a reference measurement that eliminates the need for precise antenna gain characterization. Subsequent measurements of unknown objects are then relative to this calibration reference, thereby achieving high precision without requiring complex gain pattern knowledge.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the measurement approach from absolute measurements requiring precise gain parameters to relative measurements where the calibration target's known radar cross section serves as a reference parameter. This parameter transformation allows the system to determine unknown radar cross sections by comparing ratios rather than relying on absolute gain values, thereby reducing sensitivity to gain determination errors.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If precise antenna gain patterns are required for accurate radar cross section measurements, then measurement accuracy can be maintained, but the ease of operation and accessibility of the measurement system deteriorates

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidsystem accessibility
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The calibration target serves as a self-calibrating reference that enables the measurement system to determine its own performance characteristics. By measuring the calibration target with known properties, the system automatically establishes reference values without requiring external calibration data or complex gain pattern measurements, thereby simplifying operation while maintaining accuracy.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The calibration target acts as an intermediary that bridges the gap between the measurement system and unknown objects. Instead of requiring direct knowledge of antenna gain patterns, the system uses the calibration target as a中介 reference point, making the measurement process more accessible and easier to operate while preserving measurement accuracy through the known reference properties.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If traditional measurement methods are used, then existing equipment can be utilized, but the reliability of measurements deteriorates due to sensitivity to errors in gain determination

Engineering Contradiction:
Improveequipment availabilityVSAvoidmeasurement reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The calibration target with known radar cross section serves as a reliable intermediary reference that anchors the measurement process. By establishing measurements relative to this known reference, the system achieves high reliability without requiring complex or specialized equipment, as the calibration target compensates for potential errors in existing measurement apparatus.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent transforms the measurement from an absolute parameter determination (requiring precise gain values) to a relative parameter determination (using ratios relative to calibration target). This parameter change increases measurement reliability by eliminating sensitivity to gain determination errors, while still utilizing existing equipment capabilities.

Inventive Principle:
Principle #35Parameter changes

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

This approach effectively measures radar cross sections while avoiding expensive amplifiers and higher power transmissions, reducing disruption and enhancing accuracy in RFI-prone environments.

Implementation Method 1

a radar system is configured to transmit electromagnetic energy towards an object and detect backscattered energy from the object

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 2

transmit electromagnetic energy towards an object and detect backscattered energy from the object

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Data Source

PatentEP4103961B1Determination of radar cross sections of objects
Publication Date: 2026.05.20 BAE SYSTEMS PLC
  • EP4103961B1 patent drawingFigure 1
  • EP4103961B1 patent drawingFigure 2
  • EP4103961B1 patent drawingFigure 3

AI summary

A method and a system for measuring a radar cross section of an object (102). The method comprises: transmitting one or more radar pulses (402) to the object (102), each of the one or more pulses (402) having a predetermined pulse profile; for each of the one or more pulses (402), measuring a pulse return, the pulse return being the radar pulse (402) reflected by the object (102); deconvolving the measured one or more pulse returns using the predetermined pulse profile; and determining the radar cross section of the object (102) using the deconvolved one or more pulse returns.