Single-element diffractive optical system for real-time processing of synthetic aperture radar data

Area of Science:

• Optics
• Signal Processing
• Synthetic Aperture Radar (SAR)

Background:

• Polar formatting is crucial for processing spotlight-mode SAR data.
• Conventional optical methods for polar formatting face limitations due to phase continuity requirements.

Purpose of the Study:

• To present a new optical system for polar formatting SAR data.
• To demonstrate the feasibility of using a single diffractive optical element (DOE) for this task.

Main Methods:

• Development of a DOE with a transmission function incorporating branch-point phase singularities.
• Numerical computation of the DOE's transmission function.
• Simulation of diffraction patterns generated by the DOE.

Main Results:

• Successfully designed a DOE capable of complete polar formatting.
• Overcame the phase continuity constraint for DOE fabrication.
• Numerical simulations confirm the DOE's functionality.

Conclusions:

• The proposed optical system offers a simplified approach to polar formatting SAR data.
• Incorporating phase singularities in DOEs enables previously impossible optical transforms.