SAR Phase History Range Profile Navigation
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Solution Overview
Problem
Conventional synthetic aperture radar (SAR) navigation systems require extensive computational resources and data processing for image reconstruction and feature detection, which is challenging for platforms with limited computational power, especially in GPS-denied environments.
Innovation Solution
The method involves converting SAR phase history data to the range profile domain and comparing it to a template to estimate geometric transformations, reducing the need for complex image reconstruction and feature detection by using matched filtering and Wasserstein distance computations to estimate rotation and translation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional SAR image reconstruction and feature detection techniques are used, then navigation accuracy is maintained, but computational complexity and resource requirements increase significantly
Solution Approach 1:
The patent extracts only the essential geometric transformation parameters (rotation, translation, scaling) from the full SAR image processing pipeline. Instead of reconstructing complete SAR images and performing comprehensive feature detection, the method directly estimates transformation parameters by comparing range profiles of observed phase history data with template data, eliminating unnecessary computational steps while preserving navigation accuracy
Solution Approach 2:
The patent segments the navigation problem into direct geometric transformation estimation rather than full image reconstruction. By working directly with phase history data in the range profile domain and comparing it with pre-stored templates, the method divides the computational task into manageable steps: (1) compute range profiles from phase history, (2) compare with templates using correlation or Wasserstein distance, (3) estimate transformation parameters, avoiding the computationally intensive intermediate step of full SAR image formation
2Loss of information
If full SAR image reconstruction is performed, then complete scene information is obtained, but processing time and computational resources increase
Solution Approach 1:
The patent uses pre-stored template range profiles as reference copies of known scenes. Instead of reconstructing full SAR images during navigation, the system compares observed phase history range profiles with pre-computed template range profiles, extracting geometric transformation information directly from the comparison without needing complete scene reconstruction, thus reducing processing time while maintaining sufficient scene understanding for navigation
Solution Approach 2:
The patent performs preliminary computation of template range profiles offline before actual navigation operations. By pre-processing and storing reference template data in the range profile domain, the system eliminates the need for time-consuming image reconstruction during real-time navigation, as only direct comparison operations are needed during operational phases
Data Source
AI summary
Systems and methods according to one or more embodiments are provided for mapping and registration of synthetic aperture raw radar data to aid in SAR-based navigation. In one example, a SAR-based navigation system includes a memory including executable instructions and a processor adapted to receive phase history data associated with observation views of a scene. The processor further converts the received phase history data associated with the observation views to a range profile of the scene. The range profile is compared to a range profile template of the scene to estimate a geometric transformation of the scene encoded in the received phase history data with respect to a reference template.