Study On Sparse Optimization Design Of Underwater Acoustic Imaging Sensor Array

The array-based three-dimensional imaging system generally adopts a multi-subarray multi-beam system,ensure the imaging frame rate,and the high-resolution characteristics make it an imaging method with great development potential.However,the resolution of multi-subarray systems is inconsistent with the complexity of the system.The higher the resolution of multi-subarray systems,the larger the number of array elements in the array,the higher the complexity and computational load of the system.This paper mainly uses almost difference set(ADS)and phase center approximation(PC A)methods to thin the array.(1)The virtual array formed by the MIMO "Cross-Array" can be equivalent to a linear array through the product theorem.Therefore,the virtual array is suitable for the ADS optimization method.The sparse optimization of the "Cross Array" was performed,and the predicted peak side lobe level limits of the power pattern were deduced,verified and simulated.The results showed that the combination of ADS and MIMO techniques were applied.The sparse array design can significantly reduce the number of array elements,redundancy and computational complexity under the priori estimate of side lobes.(2)In order to eliminate the redundancy of virtual array elements and improve the utilization rate of array elements,a novel MIMO array is designed using the PCA method.This method can determine the element position of MIMO array and virtual array,and performed the simulation and quantitative analysis of the pattern,and comparison with other arrays.The "dual-square" array also has the advantage of small size,and in the integrated technology field,this advantage will be more prominent in the field of underwater imaging.(3)For the sparse array designed in this paper,the finite element method is used to design the sensor element.The front-end circuit of the imaging system is correspondingly improved according to the actual requirements of the array.In order to obtain the best transmission signal,the inverter circuit is redesigned and improve the transmit waveform.Build a system acquisition platform,test and analyze all test points of the system to achieve the best state,collect echo signals and do data processing.The results show that the sparse array meets the overall requirements of array imaging.