Abstract:

There exist stable interference striations in the intensity plot of shallow water low frequency acoustic field, which contain target’s motion and range information. The beam intensity expression of a horizontal array receiving signal is derived. A moving target passive ranging technique with a horizontal line array is proposed. The waveguide invariant theory and the horizontal array beam intensity before and after it changes course during the motion are used for target’s passive ranging. Before estimating parameters through Hough transformation, image processing methods including contrast stretching transformation and median filtering are used to improve the accuracy and robustness of the parameter estimation in low signal-to-noise ratio environment. Theoretical analysis and simulation results show that the moving target’s range can be estimated effectively by using the algorithm proposed. There is no restriction on whether the target moves through the closest range, it is more applicable.