ABSTRACT A feature extraction algorithm is proposed to quantitatively assess the condition of intact and damaged carbon fiber reinforced polymer (CFRP)-wrapped concrete cylinders using synthetic aperture radar (SAR) images. The proposed algorithm converts SAR images into a simplified representation, based on the shape, size, and amplitude of SAR images. In this approach, the shape of scatterers in a SAR image is characterized by average Gaussian curvature (K), area ratio (R), and SAR amplitude (I), and is represented by a K-R-I curve. SAR images of intact and damaged CFRP-wrapped concrete cylinders were generated by a stripmap SAR imaging radar system (10.5 GHz) at various inspection angles (0°, 15°, 25°, 30°, 45°, and 60°). From our experimental result, it is found that the K-R-I representation of SAR images is capable of distinguishing damaged SAR images from intact ones at different inspection angles. Quantitative dissimilarity between the K-R-I curves of intact and damaged specimens is assessed by coefficient of correlation and compared with the signal-to-noise ratio (SNR) of SAR images. It is found that the dissimilarity of K-R-I curves is closely related to the SNR of SAR images, demonstrating the feasibility and potential of the proposed K-R-I representation.

中文翻译：

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使用合成孔径雷达图像对 CFRP 混凝土圆柱体进行定量评估

摘要提出了一种特征提取算法，以使用合成孔径雷达 (SAR) 图像定量评估完整和损坏的碳纤维增强聚合物 (CFRP) 包裹的混凝土圆柱体的状况。所提出的算法根据 SAR 图像的形状、大小和幅度将 SAR 图像转换为简化表示。在这种方法中，SAR 图像中散射体的形状由平均高斯曲率 (K)、面积比 (R) 和 SAR 幅度 (I) 表征，并由 KRI 曲线表示。完整和损坏的 CFRP 包裹的混凝土圆柱体的 SAR 图像由条形图 SAR 成像雷达系统 (10.5 GHz) 在各种检测角度 (0°、15°、25°、30°、45° 和 60°) 生成。从我们的实验结果来看，结果表明，SAR 图像的 KRI 表示能够在不同的检查角度区分损坏的 SAR 图像和完整的 SAR 图像。完整和损坏样本的 KRI 曲线之间的定量差异通过相关系数进行评估，并与 SAR 图像的信噪比 (SNR) 进行比较。发现 KRI 曲线的不同与 SAR 图像的 SNR 密切相关，证明了所提出的 KRI 表示的可行性和潜力。