Wyniki wyszukiwania dla: ACOUSTIC SURVEYS

• On Some Aspects of Fish Target Strength Estimation in Shallow Waters

  Publikacja

  • M. Moszyński

  - Rok 2013

  The theory of acoustic surveys for determining fish abundance are well established in fishery acoustics. The origins of the estimation are related to overcoming the problem of unknown position of target in the beam using statistical inversion. Although recently researchers use more sophisticated echosounders that provides more informative data allowing for direct solution it is known that the results are biased due to not ideally...

• X-ray images of Baltic herring. Data analysis

  Dane Badawcze

  open access

  • J. Idczak

  Based on the developed methodology for the: (i) optimal method of catching, (ii) transporting and storing fish, (iii) measuring and (iv) analyzing X-rays images, the existing collection of X-ray images of Baltic herring, caught in October 2002 during the Swedish component of the Baltic International Acoustic Survey (BIAS) in the Baltic proper (ICES...

• The estimation of fish lenght distribution from its acoustical measures

  Publikacja

  • M. Moszyński
  • A. Stepnowski

  - ACTA ACUSTICA UNITED WITH ACUSTICA - Rok 2006

  The paper concerns the problem of estimating fish length PDF from its target strength PDF obtained from acoustic surveys. It has been shown that the target strength of single fish can be treated in the first approximation as a finction of two variables: one, which depends on fish size and the other, which depends on its angular orientation (aspect). Extending this simplified relationship to the case of fish populations allows to...