Detection of landslides due to the 2013 Thypoon Wipha from high-resolution airborne SAR images

Because of existence of various kinds of disturbances, layover effects, and shadowing, it is difficult to extract road from high-resolution SAR images. A new road center-point searching method is proposed by two alternant steps: local detection and global tracking. In local detection step, double window model is set, which consists of the outer fixed square window and the inner rotary rectangular one. The outer window is used to obtain the local road direction by using orientation histogram, based on the fact that the surrounding objects always range along with roads. The inner window rotates its orientation in accordance with the result of local road direction calculation and searches the center points of a road segment. In global tracking step, particle filter of variable-step is used to deal with the problem of tracking frequently broken by shelters along the roadside and obstacles on the road. Finally, the center-points are linked by quadratic curve fitting. In 1 m high-resolution airborne SAR image experiment, the results show that this method is effective.

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DGPS-Supported Flight Track Processing and Direct Geo-location from High Resolution Airborne SAR Images

2008 International Workshop on Education Technology and Training & 2008 International Workshop on Geoscience and Remote Sensing ◽

10.1109/ettandgrs.2008.135 ◽

2008 ◽

Author(s):

Lei Pang ◽

Qin Yan ◽

Jujie Wei ◽

Kui Yang

Keyword(s):

High Resolution ◽

Sar Images ◽

Airborne Sar

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Airborne SAR Radiometric Calibration Based on Improved Sliding Window Integral Method

Sensors ◽

10.3390/s22010320 ◽

2022 ◽

Vol 22 (1) ◽

pp. 320

Author(s):

Lu Li ◽

Fengli Zhang ◽

Yun Shao ◽

Qiufang Wei ◽

Qiqi Huang ◽

...

Keyword(s):

Remote Sensing ◽

High Resolution ◽

Integral Method ◽

Target Position ◽

Sliding Window ◽

Radiometric Calibration ◽

Sar Images ◽

Point Target ◽

Airborne Sar ◽

The Impact

To verify the performance of the high-resolution fully polarimetric synthetic aperture radar (SAR) sensor carried by the Xinzhou 60 remote-sensing aircraft, we used corner reflectors to calibrate the acquired data. The target mechanism in high-resolution SAR images is more complex than it is in low-resolution SAR images, the impact of the point target pointing error on the calibration results is more obvious, and the target echo signal of high-resolution images is more easily affected by speckle noise; thus, more accurate extraction of the point target position and the response energy is required. To solve this problem, this paper introduces image context information and proposes a method to precisely determine the integration region of the corner reflector using sliding windows based on the integral method. The validation indicates that the fully polarimetric SAR sensor on the Xinzhou 60 remote-sensing aircraft can accurately reflect the radiometric characteristics of the ground features and that the integral method can obtain more stable results than the peak method. The sliding window allows the position of the point target to be determined more accurately, and the response energy extracted from the image via the integral method is closer to the theoretical value, which means that the high-resolution SAR system can achieve a higher radiometric calibration accuracy. Additionally, cross-validation reveals that the airborne SAR images have similar quality levels to Sentinel-1A and Gaofen-3 images.

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