DOA Imaging Algorithm Based on Time-reversal Theory

Time reversal method can be successfully used to locate the unknown targets in deterministic and uniform media. However, it is not appropriate for effective dealing with stochastic effects arising from inhomogeneities in a random medium that cause multipathing. In order to improve imaging effects in random media, an active-transducer array imaging approach motivated by time reversal mirrors is proposed. DOA imaging algorithm is based on the following steps: (1) an arrival time analysis of the echo received from the scatters , (2) the singular value decomposition of the array response matrix in the frequency domain. In comparison with traditional approach, this time-resolved imaging method compresses multipathing and realizes self-adaptive focusing. We illustrate the theory with the results of numeric simulations. The approach gives an effective estimate of the cross-range of the targets and has higher detection performance and statistical stability.