Inter-element Time-Delay Estimation of Array Signals Based on Line Spectrum Phase Joint Optimization

The time differences between the received signals of array elements, which are usually preset according to the nominal array formation, directly affects the performance of beamforming. However, due to some complicated reasons such as installation errors or ocean current disturbances, the inter-element time-delay will deviate from nominal values, leading to array gain decreases. A new inter-element time-delay estimation algorithm with no need for target beam data is proposed in this paper to correct the errors introduced by array distortion. The actual time differences are estimated by phase joint optimization of the line spectrum in pre-formed beam signals, which are often estimated using tracking beam signal in conventional methods. Simulation and sea trial data processing results verify the effectiveness of the proposed method.