FURTHER ANALYSIS OF TARGET STRENGTH MEASUREMENTS OF ANTARCTIC KRILL AT 38 AND 120 KHZ - COMPARISON WITH DEFORMED CYLINDER MODEL AND INFERENCE OF ORIENTATION DISTRIBUTION

Data collected during the krill target strength experiment [J. Acoust. Soc. Am. 87, 16-24 (1990)] are examined in the light of a recent zoop lankton scattering model where the elongated animals are modeled as de formed finite cylinders [J. Acoust. Soc. Am. 86, 691-705 (1989)]. Exer cise of the model under assumption of an orientation distribution allo ws absolute predictions of target strength to be made at each frequenc y. By requiring that the difference between predicted and measured tar get strengths be a minimum in a least-squares sense, it is possible to infer the orientation distribution. This useful biological quantity w as not obtainable in the previous analysis which involved the sphere s cattering model.