To achieve the real-time detecting and localization of hypervelocity impact events, a monitoring and localization system was designed based on fiber Bragg grating (FBG) sensor network. First, the simulation model was built to study the damage evolution and wave propagation process. Subsequently, based on the response mechanism of FBG to strain, the corresponding high frequency demodulation system was designed. Furthermore, a hypervelocity impact experiment was performed to verify the effectiveness of the designed system. Finally, combined with the diamond sensor array localization algorithm, the accurate position of hypervelocity impact source can be achieved.

In this paper, to reduce the non-linear phase error caused by gamma effect of the digital projector, a novel phase difference extraction method is proposed. First, through multi-layer discrete wavelet decomposition (DWT), the components of the original phase difference at different frequencies are extracted. Subsequently, the effective components are taken by the orthogonal matching pursuit (OMP) algorithm, and the phase difference is reconstructed. According to the upper and lower envelopes of the original phase difference extracted by cubic spline interpolation, the residual threshold of OMP is set. According to the results of three-dimensional (3-D) reconstruction experiment on a standard sphere, the proposed method is capable of reducing the errors in the original phase difference and achieving a better imaging result.