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Working with Example Data

Source: vignettes/example-data/example-data.Rmd
example-data.Rmd

Overview

acousticTS includes three example scatterers and one collection of benchmark results. They provide known inputs for learning package workflows, comparing models, and checking calculations before working with custom targets.

Bundled data support learning workflows, model comparison, and validation

Included data

Object Contents Primary use
sardine An SBF scatterer with separate body and swimbladder components, based on the NOAA KRM and echoSMs resources (Southwest Fisheries Science Center 2022). Composite fish workflows.
cod An SBF scatterer representing the Cod D case, with separate body and swimbladder components (Clay and Horne 1994; Southwest Fisheries Science Center 2022). Composite fish workflows and KRM comparisons.
krill An FLS scatterer based on the krill geometry of McGehee et al. (1998) (McGehee et al. 1998). Fluid-like, elongated-body models.
benchmark_ts Stored target-strength spectra for canonical benchmark cases from Jech et al. (2015) (Jech et al. 2015; Macaulay and contributors 2024). Validation and regression checks.

The first three objects are S4 scatterers that contain geometry, physical properties, orientation, metadata, and containers for model parameters and results. benchmark_ts is a list of reference outputs, not a scatterer. The linked reference pages document each object’s complete structure and provenance.

Loading and inspecting an object

Load a dataset explicitly with data(), then use the same inspection methods available for other package objects:

library(acousticTS)

data("krill", package = "acousticTS")
class(krill)
## [1] "FLS"
## attr(,"package")
## [1] "acousticTS"
plot(krill)

Use sardine or cod to examine body-and-swimbladder targets. Use krill for a single fluid-like body. Use benchmark_ts when reproducing a documented benchmark under the same model assumptions, frequency grid, and numerical settings.

These objects support examples and validation. They are not substitutes for checking the geometry, material properties, orientation, and model assumptions required by a new scientific application.

References

Clay, Clarence S., and John K. Horne. 1994. “Acoustic Models of Fish: The Atlantic Cod (Gadus Morhua).” The Journal of the Acoustical Society of America 96 (3): 1661–68. https://doi.org/10.1121/1.410245.
Jech, J. Michael, John K. Horne, Dezhang Chu, et al. 2015. “Comparisons Among Ten Models of Acoustic Backscattering Used in Aquatic Ecosystem Research.” The Journal of the Acoustical Society of America 138 (6): 3742–64. https://doi.org/10.1121/1.4937607.
Macaulay, Gavin, and contributors. 2024. “echoSMs: Making Acoustic Scattering Models Available to Fisheries and Plankton Scientists.” In GitHub Repository. Https://github.com/ices-tools-dev/echoSMs; GitHub.
McGehee, D. E., R. L. O’Driscoll, and L. V.Martin Traykovski. 1998. “Effects of Orientation on Acoustic Scattering from Antarctic Krill at 120 kHz.” Deep Sea Research Part II: Topical Studies in Oceanography 45 (7): 1273–94. https://doi.org/10.1016/S0967-0645(98)00036-8.
Southwest Fisheries Science Center. 2022. KRM Model. National Marine Fisheries Service, National Oceanic; Atmospheric Administration. https://www.fisheries.noaa.gov/data-tools/krm-model.