114 / 1971-01-01 00:00:00

Multi-frequncy Algorithm For Real-time 3-d Acoustic Imaging With Cross Array

5117,5118,5119,5120,5121

Cross array configuration is an effective solution to the complexity associated with the large number of transducers in the planar array of underwater 3-D imaging. However, the main drawback of cross array is the time consumption of scanning the scene, which results in a low frame rate. In this paper, a multi-frequency (MF) algorithm is proposed which aims at reducing the scanning time of the cross array. The algorithm subdivides the vertical steering direction into several sectors. In each sector, a series of narrowband signals with different frequencies are emitted sequentially corresponding to different steering directions. When the echoes are received, multibeam forming algorithm is implemented in parallel in frequency-domain. The MF algorithm greatly reduces the number of transmissions and achieves a frame rate up to 5 frames per second over a distance of about 50 m. The simulation results illustrate that the MF algorithm is more effective and achieves similar performance compared with conventional algorithm.