Do dolphins benefit from nonlinear mathematics when processing their sonar returns?

@article{Leighton2012DoDB,
  title={Do dolphins benefit from nonlinear mathematics when processing their sonar returns?},
  author={Timothy G. Leighton and Gim Hwa Chua and Paul R. White},
  journal={Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences},
  year={2012},
  volume={468},
  pages={3517 - 3532}
}
  • T. Leighton, G. Chua, P. White
  • Published 8 November 2012
  • Physics, Biology
  • Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences
Dolphins have been observed to blow bubble nets when hunting prey. Such bubble nets would confound the best man-made sonar because the strong scattering by the bubbles generates ‘clutter’ in the sonar image, which cannot be distinguished from the true target. The engineering specification of dolphin sonar is not superior to the best man-made sonar. A logical deduction from this is that, in blowing bubble nets, either dolphins are ‘blinding’ their echolocation sense when hunting or they have a… 
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References

SHOWING 1-10 OF 24 REFERENCES
The Dolphin Sonar: Excellent Capabilities In Spite of Some Mediocre Properties
Dolphin sonar research has been conducted for several decades and much has been learned about the capabilities of echolocating dolphins to detect, discriminate and recognize underwater targets. The
Use of clicks resembling those of the Atlantic bottlenose dolphin (Tursiops truncatus) to improve target discrimination in bubbly water with biased pulse summation sonar
Dolphins are known to outperform man-made sonar in detecting and classifying targets in a shallow water environment where the returned signal is dominated by clutter in the vicinity of targets.
Bio-inspired wideband sonar signals based on observations of the bottlenose dolphin (Tursiops truncatus).
TLDR
Advanced time-frequency signal analysis techniques are used to generate new models for bio-inspired sonar signals and it is suggested that target discrimination could be improved through the transmission of a signal packet in which the chirp structure is varied between pulses.
Echolocation characteristics of free-swimming bottlenose dolphins during object detection and identification.
TLDR
The distribution of echolocation click-peak frequencies suggested a bias in the dominant frequency components of clicks, possibly due to mechanical constraints of the click generator.
Special section on biologically-inspired radar and sonar systems - Why dolphin biosonar performs so well in spite of mediocre 'equipment'
Dolphins have been found to have an excellent sonar system that is able to detect and recognise targets in noisy and highly reverberant environments. However, their `equipment` has only mediocre
Acoustics of echolocating dolphins and small whales
TLDR
The acoustic reception system of dolphins is discussed and topics such as auditory sensitivity, spectral analysis capabilities and directional hearing are considered, as well as properties of echolocation signals and propagation of the echlocation signals from the animals’ head.
Modeling the detection range of fish by echolocating bottlenose dolphins and harbor porpoises.
TLDR
The target strength as a function of aspect angle were measured for four species of fish using dolphin-like and porpoise-like echolocation signals and showed considerably less fluctuation with azimuth than would a pure tone pulse.
Clutter suppression and classification using twin inverted pulse sonar (TWIPS)
This paper describes the detection and classification of targets against clutter by distinguishing between linear and nonlinear scatterers and, further, by distinguishing those nonlinear targets that
Propagation through nonlinear time-dependent bubble clouds and the estimation of bubble populations from measured acoustic characteristics
For several decades the propagation characteristics of acoustic pulses (attenuation and sound speed) have been inverted in attempts to measure the size distributions of gas bubbles in liquids. While
Clutter suppression and classification using twin inverted pulse sonar in ship wakes.
TLDR
Twin inverted pulse sonar (TWIPS) is deployed in the wake of a moored rigid inflatable boat with propeller turning, and then in thewake of a moving tanker of 4580 dry weight tonnage to test its ability to distinguish between scatter from the wake and scatter fromThe seabed.
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