Abstract
For the multireceiver synthetic aperture sonar (SAS), the point target reference spectrum (PTRS) in the two-dimensional (2D) frequency domain and azimuth modulation in the range Doppler domain were first deduced based on a numerical evaluation method and accurate time delay. Then, the difference between the PTRS and azimuth modulation generated the coupling term in the 2D frequency domain. Compared with traditional methods, the PTRS, azimuth modulation and coupling term was better at avoiding approximations. Based on three functions, an imaging algorithm is presented in this paper. Considering the fact that the coupling term is characterized by range variance, the range-dependent sub-block processing method was exploited to perform the decoupling. Simulation results showed that the presented method improved the imaging performance across the whole swath in comparison with existing multireceiver SAS processor. Furthermore, real data was used to validate the presented method.
Highlights
Synthetic aperture sonar (SAS) [1] provides high resolution images via the coherent processing of successive echo data along the virtual aperture
The two hyperbolic range histories make it difficult to deduce the point of stationary phase (PSP) and point target reference spectrum (PTRS) using the method of stationary phase [9]
Considering targets at reference range, the coupling is completely removed after this step
Summary
Synthetic aperture sonar (SAS) [1] provides high resolution images via the coherent processing of successive echo data along the virtual aperture. Their method was based on the approximation that the transmitter and receiver contribute to the Doppler frequency. One is the equal Doppler contribution of the transmitter and receiver, and the other is the Taylor approximation of the transmitter’s phase and receiver’s phase This method only applies to the narrow beam case [14,15]. The accuracy of the two-way range and PSP was limited by the number of terms in the polynomial With this method, the series approximation was used twice. The PTRS, coupling term and azimuth modulation avoiding approximations were further exploited to develop the imaging processor, which compensated the coupling phase based on the sub-block processing method.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
