Research on Turning Motion Targets and Velocity Estimation in High Resolution Spaceborne SAR

Area of Science:

• Remote Sensing
• Signal Processing
• Geophysics

Background:

• High-resolution Synthetic Aperture Radar (SAR) systems are increasingly sensitive to moving target effects.
• Defocusing and other artifacts in SAR imagery are often caused by the complex motion of targets.
• Understanding and mitigating these effects is crucial for accurate SAR data interpretation.

Purpose of the Study:

• To investigate the imaging signatures of turning motion targets in SAR.
• To develop and validate a method for estimating the velocity of turning motion targets.
• To address the challenges posed by moving targets in high-resolution SAR imaging.

Main Methods:

• Modeling turning motion as a series of straight-line segments with continuously changing direction.
• Geometric modeling of turning motion within spaceborne SAR systems.
• Calculating radial velocity from azimuth offset and azimuth velocity from phase error compensation for velocity estimation.

Main Results:

• Identified distinct imaging signatures for turning motion targets, including a 'broken line' phenomenon.
• Developed a novel method for estimating both the amplitude and direction of target velocity.
• Simulation and real-world GF-3 data validated the accuracy of the imaging signature analysis and velocity estimation method.

Conclusions:

• The proposed method accurately characterizes the imaging signatures of turning motion targets in SAR.
• The developed velocity estimation technique is accurate and effective for turning motion targets.
• This research contributes to improved moving target detection and analysis in high-resolution SAR systems.