Multichannel High Resolution Wide Swath SAR Imaging for Hypersonic Air Vehicle with Curved Trajectory

Area of Science:

• Radar Systems Engineering
• Aerospace Engineering
• Signal Processing

Background:

• Hypersonic air vehicles equipped with Synthetic Aperture Radar (SAR) offer advantages but face challenges due to high-speed maneuvering and curved trajectories.
• These characteristics cause significant range migration, creating a conflict between achieving high resolution and wide swath imaging.

Purpose of the Study:

• To develop an effective SAR imaging algorithm for hypersonic platforms that overcomes range migration issues.
• To enable simultaneous high-resolution and wide-swath imaging capabilities for near-space SAR systems.

Main Methods:

• Established an imaging geometrical model tailored to hypersonic platform trajectories.
• Developed a multichannel azimuth sampling model using displaced phase center antenna (DPCA) technology.
• Proposed an efficient spectrum reconstruction model using discrete Fourier transform for azimuth uniform sampling.
• Derived an approximate range model using the minimax criterion and a coevolutionary algorithm.
• Introduced the Exact Transfer Function (ETF) algorithm to address residual phase compensation and Stolt mapping limitations.

Main Results:

• Successfully obtained azimuth uniform sampling data through multichannel signal reconstruction.
• Developed an approximate range model with optimal second-order coefficients.
• The proposed Exact Transfer Function (ETF) algorithm effectively compensates for residual phase errors.
• A range division method was presented to achieve wide swath imaging.

Conclusions:

• The Exact Transfer Function (ETF) algorithm is effective for SAR imaging on hypersonic platforms.
• The developed methods successfully address the challenges of range migration, enabling high-resolution and wide-swath imaging.
• Simulation results validate the performance and effectiveness of the proposed ETF imaging algorithm.