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Sliding Spotlight Mode Imaging with GF-3 Spaceborne SAR Sensor.
Qingjun Zhang1,2, Feng Xiao3, Zegang Ding4
1Beijing Key Laboratory of Embedded Real-time Information Processing Technology, School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China. ztzhangqj@163.com.
Sensors (Basel, Switzerland)
|December 27, 2017
Summary
This study presents an efficient imaging method for Synthetic Aperture Radar (SAR) sliding spotlight mode, achieving high-resolution wide-swath images. The developed two-step approach accurately estimates Doppler parameters, overcoming spectral folding for better focus.
Area of Science:
- Remote Sensing
- Radar Imaging
- Signal Processing
Background:
- Synthetic Aperture Radar (SAR) sliding spotlight mode offers simultaneous high resolution and wide swath (HRWS) capabilities.
- Steering the radar antenna beam is key to achieving HRWS in this mode.
- Focusing images in sliding spotlight mode presents challenges.
Purpose of the Study:
- To develop an effective imaging scheme for Synthetic Aperture Radar (SAR) sliding spotlight mode.
- To obtain well-focused SAR images using the Gaofen-3 sensor in sliding spotlight mode.
- To address the azimuth spectral folding phenomenon in sliding spotlight SAR imaging.
Main Methods:
- An integrated imaging scheme for sliding spotlight SAR echoes was proposed.
- A two-step approach was applied to the spaceborne sliding spotlight SAR imaging algorithm.
- A Doppler parameter estimation algorithm was integrated into the imaging scheme.
Main Results:
- The two-step approach successfully overcomes the azimuth spectral folding phenomenon.
- High accuracy in Doppler parameter estimation was demonstrated.
- The proposed imaging process is accurate and efficient for sliding spotlight SAR.
Conclusions:
- The developed imaging scheme provides accurate and efficient image formation for SAR sliding spotlight mode.
- The method is suitable for spaceborne SAR systems like Gaofen-3.
- This work enhances the capability of achieving HRWS imaging with SAR.
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