Ultrasonic Acoustic Remote Sensing
Acoustic Sensing
Sound waves can be used to sense the environment. This technique has been developed in nature and in our technology.
In Nature
This technique is broadly coined by the term "Echolocation" to describe its variants in different species. Some examples:
- Bats
- Bats echolocate with a frequency of 11-212kHz with most operating between 20-60kHz (Jones & Holderied, 2007).
- Cetaceans (Whales & Dolphins)
- Chong et. al. (2021) performed an experiment to test the ability of dolphins to decipher objects of various materials (but otherwise identical) with their biosonar. In their experiment, their bottlenose dolphin, Ginsan, produced frequencies in the range of 50kHz-130kHz.
- Shews
- Shrews echolocate with a frequency of 30-60kHz (Thomas & Jalili, 2004). According to Chai et. al (2020), genome data suggests that bats, cetaceans and shews experience convergent evolution, sharing the same set of genes for this skill.
In Technology
This technique is employed by different types of technology, such as in SONAR or in Seismic Inversion.
- SONAR
- Seismic Inversion
Fundamental Principle & Additional Principles
The most basic principle behind this technique rely on round trip Time-Of-Flight (TOF) measurements of reflected sound waves. However, more complicated principles can be involved. For example:
- In Seismic Inversion (oversimplified), one considers a delayed response composed of multiple reflections of waves propagating through a geologic medium to reconstruct structural layers.
- In Echolocation, bats use Doppler Shifts to locate moving targets.
Project Overview
In this project, we will use sound to sense the environment. From the previous section, it is clear that
Scope & Justification
Objectives
Tools
On the most basic level to run our experiment, we require a source of ultrasonic sound, a receiver sensitive to ultrasonic wavelengths, and a board to control these devices. Arduino provides a convenient solution these requirements.
- . Arduino UNO R3
- . HC-SR04 Ultrasonic Emitter/Sensor
Distance Measurement
References
Jones, G., & Holderied, M. W. (2007). Bat echolocation calls: adaptation and convergent evolution. Proceedings. Biological sciences, 274(1612), 905–912. https://doi.org/10.1098/rspb.2006.0200
Wei, C., Hoffmann-Kuhnt, M., Au, W.W.L. et al. (2021). Possible limitations of dolphin echolocation: a simulation study based on a cross-modal matching experiment. Sci Rep 11, 6689. https://doi.org/10.1038/s41598-021-85063-2
Thomas, J. A., Moss, C., & Vater, M. (2004). Review of echolocation in insectivores and rodents. In Echolocation in bats and Dolphins. essay, University of Chicago Press. https://www.researchgate.net/publication/258835904_Review_of_echolocation_in_insectivores_and_rodents
Chai, S., Tian, R., Rong, X., Li, G., Chen, B., Ren, W., Xu, S. & Yang, G. (2020). Evidence of Echolocation in the Common Shrew from Molecular Convergence with Other Echolocating Mammals. Zoological Studies 59: 4. https://doi:10.6620/ZS.2020.59-4
