Super-directional element distribution model of NLA based on TR

The establishment of a designed model was discussed based on time reversal(TR) of non-uniformed linear array(NLA) as a precondition of the target signal. By using the multi-path channel classic ray theory under symmetrical shallow water environment, and adopting the line of sight signal components as a reference factor, the impact factor of NLA's TR focusing performance and directional diagram was derived. The conclusion shows that the designed model not only overcomes multi-path channel influence, but improves direction of arrival(DOA) accuracy under low signal-to-noise, based on TR adaptive correction characteristics of multi-path propagation delay, while the directional diagram F(θ) is related to bandwidth, arrayed factor d_i, multi-path M and snapshots K. The simulation results show that directional diagram of 7 elements distribution NLA has super-directivity compared to uniformed linear array via TR, and accurately estimates the target orientation under both -6 dB and -13 dB signal-to-noise condition.