System Design and Echo Preprocessing of Spaceborne Squinted Two-Dimensional Beam Scanning Synthetic Aperture Radar.

Area of Science:

• Remote Sensing
• Signal Processing
• Radar Imaging

Background:

• Conventional squinted sliding spotlight SAR imaging faces challenges with reduced swath width and complex processing.
• These issues stem from varying squint angles and significant range cell migration (RCM).

Purpose of the Study:

• To propose a novel 2D beam scanning mode for high-resolution wide swath (HRWS) SAR imaging.
• To overcome the limitations of conventional methods in swath width and processing complexity.

Main Methods:

• Synchronous scanning of azimuth and range beams to achieve flexible imaging.
• Utilizing azimuth beam scanning for improved azimuth resolution.
• Employing range beam scanning to illuminate an oblique wide swath, mitigating RCM and swath width reduction.

Main Results:

• The proposed 2D beam scanning mode extends both swath width and length compared to conventional sliding spotlight mode.
• An echo signal preprocessing approach involving range data extension and azimuth data upsampling was developed.
• A system example demonstrated 0.5 m resolution, 60 km swath width, and 134 km azimuth coverage.

Conclusions:

• The novel 2D beam scanning mode effectively enables HRWS SAR imaging with enhanced performance.
• Simulation experiments on point targets validated the proposed imaging mode and system design.