Fig.1. Low resolution model of sphere with radius r=1.905 cm
inside wave-length box with a size of 38kHz wavelength.

Fig.2. Scattering pattern at 38kHz obtained for low resolution
model of a soft sphere with radius r=1.905 cm along with exact
solution (dashed-blue).

Fig.3. Target strength pattern at 38kHz obtained for low resolution
model of a soft sphere with radius r=1.905 cm along with exact
solution (dashed-blue).

Fig.4. 3D Backscattering length pattern at 38kHz for low resolution
model of a sphere with radius r=1.905 cm.

Fig.5. Target strength frequenecy dependance for low resolution
model of a soft sphere with radius r=1.905 cm along with exact
solution (dashed-blue). The angular axis values corespond to
frequencies in kHz.

Fig.6. 3D backscattering length pattern at 38kHz for a soft sphere
with radius r=1.905 cm (exact solution).

Fig.7. High resolution model of a sphere with radius r=1.905 cm.
Wave-length box is set for 70 kHz and is fully inside
the sphere.

Fig.8. Scattering length pattern at 70kHz for high reolution model
of a sphere with radius r=1.905 cm along with exact solution.

Fig.9. Scattering length pattern at 120kHz for high reolution model
of a sphere with radius r=1.905 cm along with exact solution.

Fig.10. Target strength frequency dependence for high resolution
model of the soft sphere with radius r=1.905 cm along with exact
solution (dashed-blue). The angular axis values corespond to
frequencies in kHz.

Fig.11. The visualisation of the exact sphere, for which calculations
are based on theoretical equations.

Fig.12. Scattering length for of the exact sphere for three
frequencies: 38 kHz (dashed-blue), 120 kHz (dashed-blue)
and 200 kHz (red).

Fig.13. The model of Yellowfin tuna swimbladder conatining 1500
triangles. The green dot represents wave direction from
dorsal aspect (from up).

Fig.14. Scattering strength from dorsal aspect (θ₀=270ˆ
φ₀=0ˆ) of Yellowfin tuna swimbladder model at 38 kHz.

Fig.15. The model of Yellowfin tuna swimbladder conatining 1500
triangles. The green dot represents wave direction from
lateral aspect (from one side).

Fig.16. Scattering strength from lateral aspect (θ₀=0ˆ
φ₀=90ˆ) of Yellowfin tuna swimbladder
model at 38 kHz.

Fig.17. Two target strengths patterns of Yellowfin tuna swimbladder
model at 38 kHz obtained as 15ˆ scan along
φ₀=0 (dashed-blue) and φ₀=90 (red).

Fig.18. 3D backscattering length pattern at 38kHz of the Yellowfin
tuna swimbladder model obtained as 10ˆ scan along both
direction angles.

Fig.19. The model of Gadus morhua swimbladder from echoSMs
github repository.

Fig.20. 3D backscattering length pattern at 38kHz of the Gadus
morhua swimbladder model obtained as 10ˆ scan along
both direction angles.

Fig.21. The model of Cod swimbladder from KRM model web-page.

Fig.22. 3D backscattering length pattern of the Cod
swimbladder model at 38kHz obtained as 10ˆ scan
along both direction angles.