High resolution imaging with ultra-wideband signals for limited aperture

In this paper, a novel approach to high resolution underwater acoustic imaging is proposed for limited aperture. The proposed imaging approach is based on cross-correlation and high resolution is achieved by using ultra-wideband (UWB) signals in combination with cross-correlation processing. The idea of the proposed imaging approach is that cross-correlation of a pair of the received UWB signals can produce extremely short impulse with the benefit of large relative bandwidth of UWB signals. The obtained extremely short impulses of all pairs of receivers are delayed and summed for high resolution image formation. The cross-correlation-based approach is suitable for the case of limited aperture by using UWB signals. A number of numerical simulations are presented to demonstrate the effectiveness of the proposed approach. Compared with the conventional narrowband imaging approach, the proposed approach gives better image resolution.