Slow time dimension and fast time dimension spatial resolutions of acoustic tomography model are the same,only depend on the highest frequency of transmitted signals,and these resolutions are better than that of focused synthetic aperture sonar.Existing underwater tomography mostly uses time-domain back-projection algorithm,it requires a large amount of calculation.Here,a wavenumber domain imaging method based on the projection slicing theory was proposed,it could integrate sub-frequency band and polar coordinate format.The inverse Fourier transform problem of rectangular coordinate interpolation of circular annular space spectrum under broadband transmission was converted into the fusion problem after inversion of single frequency point circular space spectrum to reduce the estimation error brought by conventional broadband wavenumber domain circular annular interpolation,overcome the problem of the reconstructed target distribution function being hollow when interpolation inverse transform was performed for circular annular spatial spectrum,improve computational efficiency,and effectively suppress high sidelobe's effects during single frequency wavenumber domain imaging results being a Bessel function.It was shown that under the same conditions,the imaging accuracy of the proposed method is significantly improved compared with that of focused synthetic aperture sonar.
关键词
分频带处理/声层析/极坐标格式处理/波数域插值
Key words
sub-frequency band processing/acoustic tomography/processing with polar coordinate format/wavenumber domain interpolation
维普
万方数据