Target-tracking in a parametric sonar beam, with applications to calibration

Abstract

The difference-frequency band of the Kongsberg TOPAS PS18 sub-bottom profiling parametric sonar is very directional. Calibration of this by the standard-target method requires precise positioning and knowledge of target location. This was apparent during the first calibration trial performed on 10 December 2008. The proximity of split-beam transducers of the Simrad EK60/18-and 38-kHz scientific echo sounder to the TOPAS transducer on the hull of R/V "G. O. Sars" has been exploited, with synchronous operation of the several sonars. While results with a single split-beam transducer would be unambiguous, the availability of data from two split-beam transducers allows quantitative comparison of performance. Results from this comparison are presented here. Significantly, agreement of the respective measurements is strong at an approximate target range of 90 m, fair at 220 m, but rather weak at 325 m. The context of a moving target is noted. The challenge of target-positioning and -tracking in a dynamic environment, more so in the presence of wind and underwater currents, may be met by use of a split-beam scientific echo sounder, if with a range limitation still to be defined.

Numerical and Experimental Studies on Inclined Incidence Parametric Sound Propagation

“…e parametric array technology can generate broadband, high directivity, and side-lobe suppressed low-frequency sound beams by using a small aperture array [4][5][6]. is parametric sound feature makes the parametric sonar more suitable for high-directivity sound beam noninvasive measurement and high-resolution sub-bottom profiling [7][8][9]. When the parametric sound is obliquely irradiated into different media, the acoustic propagation path changes due to the medium parameters, which has a certain influence on the application of the parametric sound.…”

Parametric Underwater Transmission Based on Pattern Time Delay Shift Coding System

“…Parametric emission method and its relationship with the underwater environment are discussed in [7,8]. Subsequently, the parametric array was used in medical inspections [9], marine biological exploration [10], target tracking [11], and buried object detection [12]. The emission issue of broadband difference frequency signal was studied in [13].…”

Experimental Study of a Broadband Parametric Acoustic Array for Sub‐Bottom Profiling in Shallow Water

“…Later, Berktay further deduced the relative emission theory of parametric acoustic arrays and promoted their application [4]. Because it offers a low-frequency sound source with a narrow beam and no sidelobes, the technology has been used in subbottom profiling [5], industrial flaw detection [6], medical examination [7], biological detection [8], target tracking [9], and underwater acoustic communication [10,11]. However, its most mature application in underwater acoustics is still the sub-bottom profiler [12][13][14].…”