Direction-finding method with a small number of spatially offset directional characteristics

摘要

The frequency spectra of the group signals of the directional characteristics of a panoramic sonar system are formed and the direction determined per spectral line. In the lower frequency range, the focusing of the directional characteristics is only slight and the direction finding is inadequate, particularly to locate targets at long ranges. According to the invention, the spectral lines of all the directional characteristics at the same frequency form an angle function, as an independent variable, over the receiving direction of the directional characteristic. Their Fourier transform provides a fundamental. The phase of the fundamental is determined and indicates the direction to the target. The direction-finding method can be used advantageously in underwater sound technology at low frequencies, using a conventional cylinder base having four directional characteristics offset through 90@.