Universal Radar Waveform Subaperture Imaging
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Solution Overview
Problem
Existing radar imaging schemes require a high number of pulses to maintain image quality, leading to inefficient use of radar resources and incompatible modes of operation for different intelligence, surveillance, and reconnaissance missions.
Innovation Solution
The use of universal radar waveforms with uneven sampling patterns, such as quadratic residue patterns, and peak correction algorithms to process a reduced number of pulses while maintaining image quality, allowing for simultaneous imaging of disparate areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a high number of radar pulses are used to maintain image quality, then image resolution and quality are improved, but radar resource efficiency deteriorates
Solution Approach 1:
The patent divides the radar pulse transmission into multiple subapertures, each covering a different area. By segmenting the imaging task across multiple subapertures with fewer pulses each, the system achieves complete area coverage with reduced total pulse count, thereby improving radar resource efficiency while maintaining image quality.
Solution Approach 2:
The patent introduces a spatial dimension by transmitting pulses at multiple different angles (azimuth angles) simultaneously. This angular dimension allows the system to image multiple areas at once, reducing the number of pulses needed for each individual area while maintaining overall image quality and resolution.
2Adaptability or versatility
If multiple intelligence, surveillance, and reconnaissance modes are supported simultaneously, then mission versatility is improved, but system complexity deteriorates
Solution Approach 1:
The patent creates a universal radar waveform that can perform multiple functions (imaging, MTI, HRTI) simultaneously by transmitting pulses at multiple angles and using multiple subapertures. This multi-functional waveform allows a single system to support various intelligence, surveillance, and reconnaissance modes without requiring separate specialized systems, thereby reducing overall system complexity.
3Productivity
If the number of radar pulses is reduced, then radar resource efficiency is improved, but image quality deteriorates
Solution Approach 1:
The patent merges data from multiple subapertures and multiple angle transmissions to reconstruct complete area images. By combining the information from these multiple sources, the system achieves high image quality with fewer pulses per subaperture, thereby improving radar resource efficiency without sacrificing image quality.
Solution Approach 2:
The patent transmits radar pulses at multiple different angles simultaneously, adding an angular dimension to the data collection. This allows the system to gather information about multiple areas at once, reducing the number of pulses needed for each individual area while maintaining image quality through the combined data from all angles.
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 reduces the number of radar pulses required while maintaining equivalent resolution and quality of SAR images, enabling simultaneous imaging of multiple areas without significant degradation.
Implementation Method 1
an electromagnetic pulse is transmitted from a radar platform, and this transmitted pulse is scattered back to the radar platform by various objects
Implementation Method 2
The roundtrip time taken by the pulse to both travel from the radar platform to the scattering object and back therefrom is proportional to the distance between the radar platform and the object
Implementation Method 3
If the object is at a certain distance from the radar platform and is moving toward the radar platform, then the complex radar pulses will rotate in phase with a positive frequency. Similarly, if the object is moving away from the radar platform, then the complex radar pulses will rotate in phase with a negative frequency
Data Source
AI summary
A new approach to radar imaging is described herein, in which radar pulses are transmitted with an uneven sampling scheme and subsequently processed with novel algorithms to produce images of equivalent resolution and quality as standard images produced using standard synthetic aperture radar (SAR) waveforms and processing techniques. The radar data collected with these waveforms can be used to create many other useful products such as moving target indication (MTI) and high resolution terrain information (HRTI). The waveform and the correction algorithms described herein allow the algorithms of these other radar products to take advantage of the quality Doppler resolution.