针对水下声发射源较多，为能准确鉴别敌我声呐发射源问题。利用数字水印技术，结合分数阶傅里叶变换（FRFT）的良好时频特性，提出了基于分数阶傅里叶变换的声呐水印方法，通过在声呐信号的分数阶傅里叶变换域进行数字水印的嵌入，结合声呐信号在分数阶傅里叶变换的系数特性，选择合适的水印位置。利用嵌入前与嵌入后信号的特性自适应设定水印检测阈值，实现对声呐信号的鉴别。通过仿真分析验证了该方法的可行性，在仿真结果中示出该方法在保证具有较高的分辨力，以及较大的水印容量的同时，水印的鲁棒性较好，检测精度得到了进一步的提高。
In view of underwater acoustic emission source is more. To identify the enemy emission source sonar accurately. Using the digital watermarking technology, combined with the good time-frequency characteristics of fractional Fourier transform (FRFT), Sonar watermarking method is proposed based on fractional Fourier transform, digital watermark embedding in fractional Fourier transform domain of sonar signals, combined with the coefficients features in the fractional fourier transform domain of sonar signal, Selecting the appropriate watermark position. According to the characteristic of the signal before embedding and after embedding, the watermark detection threshold is adaptive. To achieve the identification of sonar signals. The feasibility of this method is verified by the simulation analysis, This method is shown in the simulation results with higher resolution and larger watermark capacity, better robustness, At the same time the performance of the detection accuracy can be further improved.
2017,39(9): 142-147 收稿日期：2016-11-03
DOI：10.3404/j.issn.1672-7649.2017.09.028
分类号：TN929
基金项目：国家自然科学基金资助项目（11574120）；江苏省自然科学基金资助项目（BK20161359）；江苏高校高技术船舶协同创新中心/江苏科技大学海洋装备研究院资助项目（HZ2016010）；水声对抗技术重点实验室基金资助项目
作者简介：丁智慧(1992-),女,硕士研究生,研究方向为水声信号处理
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