Underwater targets tomographic imaging based on sub-frequency band processing with polar coordinate format
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.
sub-frequency band processingacoustic tomographyprocessing with polar coordinate formatwavenumber domain interpolation
万方数据
维普
