Deep Learning as Applied in SAR Target Recognition and Terrain Classification
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摘要:
深度卷积网络等深度学习算法变革了计算机视觉领域,在多种应用上的效果都超过了以往传统图像处理算法。该文简要回顾了将深度学习应用在SAR图像目标识别与地物分类中的工作。利用深度卷积网络从SAR图像中自动学习多层的特征表征,再利用学习到的特征进行目标检测与目标分类。将深度卷积网络应用于SAR目标分类数据集MSTAR上,10类目标平均分类精度达到了99%。针对带相位的极化SAR图像,该文提出了复数深度卷积网络,将该算法应用于全极化SAR图像地物分类,Flevoland 15类地物平均分类精度达到了95%。
Abstract:Deep learning such as deep neural networks has revolutionized the computer vision area. Deep learning-based algorithms have surpassed conventional algorithms in terms of performance by a significant margin. This paper reviews our works in the application of deep convolutional neural networks to target recognition and terrain classification using the SAR image. A convolutional neural network is employed to automatically extract a hierarchic feature representation from the data, based on which the target recognition and terrain classification can be conducted. Experimental results on the MSTAR benchmark dataset reveal that deep convolutional network could achieve a state-of-the-art classification accuracy of 99% for the 10-class task. For a polarimetric SAR image classification, we propose complex-valued convolutional neural networks for complex SAR images. This algorithm achieved a state-of-the-art accuracy of 95% for the 15-class task on the Flevoland benchmark dataset.
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表 1 SAR图像解译与计算机视觉的差异
Table 1. Comparison of SAR imagery interpretation and computer vision
特性 SAR图像解译 计算机视觉 波段 微波 可见光 成像原理 相位相干叠加 能量聚焦叠加 投影方向 距离向-方位角 俯仰角-方位角 典型视角 空天对地观测 第一人称视角 数据构成 幅度相位、多通道、多模式 RGB、视频 表 2 SOC实验条件下的混淆矩阵
Table 2. Confusion matrix under SOC setting
Class BMP-2 BTR-70 T-72 BTR-60 2S1 BRDM-2 D7 T-62 ZIL-131 ZSU-234 Pcc (%) BMP-2 194 0 1 0 1 0 0 0 0 0 98.98 BTR-70 0 195 0 0 0 1 0 0 0 0 99.49 T-72 0 0 196 0 0 0 0 0 0 0 100 BTR-60 1 0 0 188 0 0 0 1 1 4 96.41 2S1 0 0 0 0 269 4 0 0 0 1 98.18 BRDM-2 0 0 0 0 0 272 0 0 0 2 99.27 D7 0 0 0 0 0 0 272 1 1 0 99.27 T-62 0 0 0 0 0 0 0 272 1 0 99.64 ZIL-131 0 0 0 0 0 0 0 0 273 1 99.64 ZSU-234 0 0 0 0 0 0 1 0 0 273 99.64 Total 99.13 表 3 Flevoland数据分类结果
Table 3. Flevoland result
Class 训练样本数 测试样本数 实数网络准确率 复数网络正确率 Stem beans 1245 282 100 100 Peas 1225 308 99.26 98.38 Forest 1184 295 99.36 99.66 Lucerne 1225 293 93.16 99.66 Wheat 1163 291 97.60 95.88 Beet 1213 287 97.18 99.30 Potatoes 1220 286 89.42 97.20 Bare soil 1236 310 99.36 88.06 Grasses 1202 329 71.43 91.79 Rapeseed 1216 290 87.58 91.72 Barley 1207 311 98.49 99.36 Wheat2 1176 304 83.23 92.43 Wheat3 1224 325 77.61 94.77 Water 1138 284 59.27 96.13 Buildings 126 24 100 100 Total 17000 4219 89.49 95.97 -
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