Study On Reflection Coefficient Measurement Of Anechoic Coating Based On Compressive Sensing

The stealth performance of a submarine plays a vital role in its military operations.The passive stealth technology for submarines often uses anechoic coating to reduce the submarine’s own radiated sound and detect echoes.The technology of anechoic coating is constantly update.It is necessary to measure its acoustic performance.The measurement of the large sample reflection coefficient is an important part of the acoustic performance evaluation of the anechoic coating,which is generally measured in the laboratory.In a limited space(such as a water tank),it is difficult to directly separate the multipath interference,which brings errors to the measurement results.Aiming at the reverberation problem of low-frequency reflection coefficient measurement in limited space,an anechoic coating reflection coefficient measurement method based on compressed sensing time delay estimation algorithm is proposed,which can estimate high-resolution multipath time delay estimation using broadband signals.Taking into account that the reflection coefficient measurement needs to estimate the amplitude information of the target echo,the least square method is used to estimate the multipath response amplitude of the single-frequency signal,thereby separating the multipath signal and realizing the measurement of the reflection coefficient.A channel model in a limited measurement space is established,and on this basis introduced conventional compressive sensing time delay estimation algorithms and grid-free compressive sensing time delay estimation algorithms.Then,the necessity of time delay estimation algorithm combined with least square method to estimate reflection coefficient is demonstrated,and a method for measuring reflection coefficient of anechoic coating based on compressive sensing is proposed.Then the simulation verified the feasibility of the method and it analyzed the performance of the method.Finally,an experiment was carried out,an automatic software was written,and the reflection coefficient of steel plate was measured in an anechoic water tank environment,which verified the feasibility and effectiveness of the reflection coefficient measurement method based on compressive sensing.