Accurate Range Modeling for High-Resolution Spaceborne Synthetic Aperture Radar

Area of Science:

• Remote Sensing
• Geophysics

Background:

• Spaceborne synthetic aperture radar (SAR) offers all-weather, all-day imaging capabilities.
• Traditional SAR echo models are insufficient for high-resolution spaceborne systems due to orbital and Earth rotation effects.

Purpose of the Study:

• To develop an accurate range model for high-resolution spaceborne SAR.
• To address the limitations of existing models in accurately describing range history for nonlinear trajectories.

Main Methods:

• Analysis of spaceborne SAR motion trajectory and Doppler parameters.
• Development of an advanced equivalent squint range model (AESRM) incorporating third-order and fourth-order error terms.
• Evaluation of existing range models and comparison with the proposed AESRM.

Main Results:

• The proposed AESRM accurately fits the actual range history of spaceborne SAR.
• AESRM effectively compensates for high-order term errors in range history.
• Point target simulations validated significant improvements in fitting accuracy for nonlinear trajectories.

Conclusions:

• The advanced equivalent squint range model (AESRM) enhances the accuracy of spaceborne SAR imaging.
• AESRM provides a simplified yet effective approach for designing advanced SAR imaging algorithms.
• This model enables higher resolution and more precise radar imaging for spaceborne SAR systems.