Windmill Radar Antenna Compressive Sensing for Stationary Cross-Range Resolution

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Solution Overview

Problem

Surveillance systems with radar antennas mounted on windmill blades face challenges in achieving high cross-range resolution when there is insufficient wind to rotate the blades, rendering them non-operational.

Innovation Solution

The implementation of a compressive sensing technique for radar antennas mounted on windmill blades, allowing for cross-range image reconstruction using fewer measurements, even in the absence of wind, by employing a measurement matrix that models radar echoes and geometry, and optimizing signal amplitudes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If radar antennas are mounted on windmill blades to achieve high cross-range resolution, then cross-range resolution is improved, but the system becomes non-operational in the absence of wind

Engineering Contradiction:
Improvecross-range resolutionVSAvoidoperational availability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system dynamically adapts its operation mode based on wind conditions. When wind is present, the blade rotates and SAR technique is used; when wind is absent, the blade remains stationary and compressive sensing technique is applied. This dynamic switching ensures continuous operational availability while maintaining measurement precision across different environmental conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the measurement and processing parameters based on the operational state. In rotating mode, continuous SAR processing parameters are used. In stationary mode, compressive sensing parameters (measurement matrix, sparsity constraints, optimization algorithms) are applied. This parameter adaptation allows the system to maintain cross-range resolution capability regardless of wind conditions.

Inventive Principle:
Principle #35Parameter changes

2Loss of information

If traditional Nyquist-based sampling methods are used for stationary radar, then sufficient data is collected, but the data volume and system complexity increase

Engineering Contradiction:
Improvedata completenessVSAvoidsystem complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The compressive sensing technique extracts only the essential information needed for cross-range imaging from the radar measurements. By exploiting the sparsity of the cross-range image in an appropriate basis, the system extracts meaningful target information while discarding redundant data, thereby reducing data volume and system complexity while maintaining information completeness.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of collecting complete Nyquist-rate data, the system uses partial measurements that are sufficient for reconstructing the cross-range image through compressive sensing algorithms. This partial action approach collects only the minimum necessary data points, reducing the burden on data storage and processing systems while still achieving the required imaging quality.

Inventive Principle:
Principle #16Partial or excessive action

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 enables enhanced cross-range resolution in both rotating and stationary scenarios, using fewer data points than traditional methods, and accommodates various environmental and system conditions, providing effective target detection and classification.

Implementation Method 1

at least one radar antenna mounted on a blade of a windmill

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 2

The measurement matrix E may contain a model of a radar echo s

Methodology Applied
Scientific EffectEcho: Echo

Implementation Method 3

means to apply a compressive sensing technique when the blade does not rotate

Methodology Applied
Scientific EffectCompressive sensing:

Data Source

PatentUS8330643B2Surveillance system for detecting targets with high cross-range resolution between targets
Publication Date: 2012.12.11 THALES NEDERLAND BV
  • US8330643B2 patent drawing
  • US8330643B2 patent drawing
  • US8330643B2 patent drawing

AI summary

A surveillance system for detecting targets with high cross-range resolution between targets. The system includes at least two radar antennae mounted on blades of a windmill and is configured to apply a compressive sensing technique when the blades do not rotate.