SAR Navigation Using CNN Range Profile Matching

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Solution Overview

Problem

Existing SAR-based navigation systems face challenges in low SWaP autonomous platforms due to high computational complexity and resource requirements, exacerbated by noise in SAR images like glint and multiplicative speckle, which reduce feature detection reliability and increase processing demands.

Innovation Solution

A synthetic aperture radar system utilizing a convolutional neural network (CNN) that directly processes range profile data to estimate registration parameters by concatenating observed and template data, eliminating the need for image reconstruction and iterative optimization, thereby reducing computational and resource needs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional SAR image processing techniques are used for feature detection and matching, then navigation registration can be achieved, but computational complexity and resource requirements increase significantly

Engineering Contradiction:
Improvenavigation registration accuracyVSAvoidcomputational complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and processes only the range profile data from SAR images, separating this critical navigation information from the full image processing pipeline. By focusing solely on range profiles rather than complete SAR image reconstruction and feature detection, the system reduces computational complexity while maintaining navigation registration accuracy through direct range profile matching.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If noise mitigation methods are applied to reduce glint and speckle effects, then feature detection reliability improves, but computational resources and processing time increase

Engineering Contradiction:
Improvefeature detection reliabilityVSAvoidcomputational energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent performs preliminary extraction of range profile data from SAR images before applying any noise mitigation or processing techniques. By pre-processing the data to isolate range profiles and using these directly for matching, the system reduces the need for computationally intensive noise mitigation methods while maintaining feature detection reliability through the inherent robustness of range profile characteristics.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If complete SAR image reconstruction is performed for navigation, then accurate scene representation is achieved, but processing time and computational power requirements increase

Engineering Contradiction:
Improvescene representation accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts range profile data directly from SAR measurements without performing complete image reconstruction. This extraction approach obtains sufficient scene representation information for navigation purposes while avoiding the computationally intensive and time-consuming full SAR image reconstruction process, thereby reducing processing time while maintaining adequate measurement precision for navigation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies partial processing by working only with range profile data rather than complete SAR images. This partial action approach processes only the essential navigation-relevant information (range profiles) without the excessive computation required for full image reconstruction, achieving a balance between scene representation accuracy and processing efficiency suitable for low SWaP platforms.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS11255960B2Synthetic aperture radar (SAR) based convolutional navigation
Publication Date: 2022.02.22 THE BOEING CO
  • US11255960B2 patent drawing
  • US11255960B2 patent drawing
  • US11255960B2 patent drawing

AI summary

A synthetic aperture radar (SAR) system is disclosed. The SAR comprises a memory, a convolutional neural network (CNN), a machine-readable medium on the memory, and a machine-readable medium on the memory. The machine-readable medium storing instructions that, when executed by the CNN, cause the SAR system to perform operations. The operation comprises: receiving range profile data associated with observed views of a scene; concatenating the range profile data with a template range profile data of the scene; and estimating registration parameters associated with the range profile data relative to the template range profile data to determine a deviation from the template range profile data.