基于Chirp Scaling成像算法的高分辨聚束式合成孔径声呐  

A chirp scaling algorithm for high-resolution spotlight synthetic aperture sonar imaging

作　　者：张友文[1] 孙大军[1] 田坦[1] 

机构地区：[1]哈尔滨工程大学水声工程学院,黑龙江哈尔滨150001

出　　处：《声学技术》2006年第4期271-275,共5页Technical Acoustics

基　　金：哈尔滨工程大学(HEUFT05034)

摘　　要：基于两步处理算法和ChirpScaling算法,提出一种适用于条带式成像算法的通用高分辨聚束式合成孔径声呐(SAS)模型。该模型结合了谱分析(SPECAN)算法和ChirpScaling算法的优点,算法首先采用deramp和升采样处理技术实现方位的粗聚焦,消除了聚束式SAS特有的方位频谱混迭现象,然后应用ChirpScaling原理实现距离的精确聚焦,并补偿deramp处理引起的方位相位误差,实现方位精聚焦。基于该通用模型,给出了实现的步骤,整个算法无需任何插值操作,只需复乘和FFT即可完成。该算法适用于宽测绘带高分辨率聚束式SAS的精确而高效成像处理。最后,通过计算机仿真,验证了该通用模型的有效性。Based on a two-step processing approach and the chirp scaling algorithm, a general high-resolution spotlight synthetic aperture sonar （SAS） model suitable for broadside imaging is presented. The model combines the advantages of the SPECAN and chirp-scaling algorithms. Azimuth coarse focusing is first achieved with deramp processing and upsampling operations, and the azimuth spectral aliasing typical of spotlight SAS is overcome. Precise range focusing is then achieved based on the chirp scaling principle. The residual azimuth phase errors are compensated for to acquire refined azimuth focusing. Using the general spotlight model, an implementation is given. The whole algorithm can he implemented by complex multiplication and FFT without any data interpolation. The algorithm is suited to wide range swath high-resolution spotlight SAS imaging. Computer simulation shows validity of the general model.

关 键 词：合成孔径声呐 聚束模式 CHIRP SCALING算法 

分 类 号：TP721.2[自动化与计算机技术—检测技术与自动化装置]