Refocusing Moving Ship Targets in SAR Images Based on Fast Minimum Entropy Phase Compensation

Area of Science:

• Remote Sensing
• Signal Processing
• Maritime Surveillance

Background:

• Moving ship targets in synthetic aperture radar (SAR) images suffer from blurring due to motion during data acquisition.
• Accurate imaging of these targets is crucial for maritime surveillance and requires effective motion compensation techniques.

Purpose of the Study:

• To develop and validate a novel method for refocusing moving ship targets directly within SAR images.
• To leverage inverse synthetic aperture radar (ISAR) principles for motion compensation in the image domain, rather than raw data.

Main Methods:

• Exploitation of the inverse synthetic aperture radar (ISAR) technique for image-based refocusing.
• Application of a fast minimum entropy phase compensation method, an iterative approach, to estimate and correct phase errors.
• Processing SAR images directly, avoiding the complexities of raw echo data manipulation.

Main Results:

• Successfully refocused blurred ship targets in SAR imagery.
• Demonstrated the effectiveness of the image-domain processing approach.
• Validated the method using diverse datasets including Spaceborne TerraSAR-X, Gaofeng-3, and airborne SAR images.

Conclusions:

• The proposed ISAR-based method offers an effective solution for refocusing moving ship targets in SAR images.
• Processing in the SAR image domain presents advantages over traditional raw data processing for motion compensation.
• The technique shows promise for enhancing maritime surveillance capabilities through improved SAR imaging of moving vessels.