A wrapper function that automatically creates generalized and/or canonical shapes for TS modeling.
create_shape.RdA wrapper function that automatically creates generalized and/or canonical shapes for TS modeling.
Value
Chu, D., Foote, K.G., and Stanton, T.K. 1993. Further analysis of target strength measurements of Antarctic krill at 38 and 120 kHz: Comparison and deformed cylinder model and inference of orientation distribution. The Journal of the Acoustical Society of America, 93(5): 2985-2988. https://doi.org/10.1121/1.405818
Smith, J.N., Ressler, P.H., and Warren, J.D. 2013. A distorted wave Born approximation target strength model for Bering Sea euphausiids. ICES Journal of Marine Science, 70(1): 204-214. https://doi.org/10.1093/icesjms/fss140
Details
The shape argument specifies what shape for the function to generate into the desired shape for TS modeling. Options currently include:
| Object shape | shape = ... | Parameters | Root function | ||
| Discrete/tapered cylinder | "cylinder" | length, radius | cylinder(...) | ||
| Polynomial cylinder | "polynomial_cylinder" | length, radius, polynomial | polynomial_cylinder(...) | ||
| Prolate spheroid | "prolate_speroid" | length, radius | prolate_spheroid(...) | ||
| Sphere | "sphere" | radius | sphere(...) |
Model Parameter Definitions
length: the x-axis length of the shape.
radius: the radius of the shape when applicable.
length_radius_ratio: the length-to-radius ratio (L/A), which specifically refers to the radius at the mid-point of the cylinder and should be the maximum value. A typical L/A ratio in the literature is 16 for krill.
taper: the taper order (n), which parameterizes the tapering function reported by Chu et al. (1993) to create a tapered cylinder. The tapering order will converge on a prolate and oblate spheroid when L > 2a and L < 2a, respectively, and n = 2. A typical taper order in the literature is 10.
polynomial: the vector of arbitrary polynomial coefficients to generate a deformed cylinder as reported by Smith et al. (2013). Although listed as a mandatory argument for the polynomial cylinder function, it has a default setting that uses the sixth-degree polynomial coefficients reported by Smith et al. (2013).