Browsing by Author "Holderied, M."

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    Baseband version of the bat-inspired spectrogram correlation and transformation receiver
    (Institute of Electrical and Electronics Engineers, 2016-06-01) Georgiev, Krasin; Balleri, Alessio; Stove, Andy; Holderied, M.
    Echolocating bats have evolved an excellent ability to detect and discriminate targets in highly challenging environments. They have had more than 50 million years of evolution to optimise their echolocation system with respect to their surrounding environment. Behavioural experiments have shown their exceptional ability to detect and classify targets even in highly cluttered surroundings. The way bats process signals is not exactly the same as in radar and hence it can be useful to investigate the differences. The Spectrogram Correlation And Transformation receiver (SCAT) is an existing model of the bat auditory system that takes into account the physiology and underlying neural organisation in bats which emit chirped signals. In this paper, we propose a baseband receiver equivalent to the SCAT. This will allow biologically inspired signal processing to be applied to radar baseband signals. It will also enable further theoretical analysis of the key concepts, advantages and limitations of the "bat signal processing" for the purpose of target detection, localisation and resolution. The equivalence is demonstrated by comparing the output of the original SCAT to that of our proposed baseband version using both simulated and experimental target echoes. Results show that the baseband receiver provides compatible frequency interference pattern for two closely located scatterers.
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    Biomimetic echolocation with application to radar and sonar sensing
    (IEEE Institute of Electrical and Electronics, 2014-03-25T00:00:00Z) Baker, C. J.; Smith, Graeme E.; Balleri, Alessio; Holderied, M.; Griffiths, H. D.
    Nature provides a number of examples where acoustic echolocation is the primary sensing modality, the most well-known of these being the bat, whale and dolphin. All demonstrate a remarkable ability to "see with sound". Using echolocation they navigate, locate and capture prey. As species, they have not only survived but have thrived in all their individual environments, often solely reliant on echolocation. All of these creatures are inherently cognitive. They all maintain a perception of their environment through the nervous system that allows them to take actions. In this paper we focus on the bat as an example of a cognitive system exploiting a memory-driven perception-action cycle, enabling it to navigate and interact with its environment. The key conceptual components of cognition and how it could be applied to man-made echoic sensors is introduced. This is followed by a description of how echoic flow fields, a bio-inspired technique that bats have been shown to use, fit guidance and control problems. We then go on to explain how bats are able to reliably distinguish between different targets. A combination of the theory and examples is used to demonstrate the vast potential for advancing the capability of made in man-made systems by adopting aspects of natural echolocating cognitive dynamic systems.
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    Sensing, cognition, and engineering application [Further Thoughts]
    (IEEE Institute of Electrical and Electronics, 2014-03-25T00:00:00Z) Baker, C. J.; Smith, Graeme E.; Balleri, Alessio; Holderied, M.; Griffiths, H. D.
    Definitions of cognition almost always use the term “knowing.” Sensors probe the environment producing stimuli that are interpreted to form a perception, but “knowing” is something that takes place within the brain of a human after being presented with sensed data or some form of image. Consider radar and air traffic control. A radar sensor scans the airspace and, using the principles of echolocation, is able to detect, locate, and display aircraft on a screen. An air traffic controller views the screen and continually repositions the aircraft using strict protocols that comply with safety of life requirements. In other words, it is the air traffic controller who supplies the cognitive component necessary to achieve air safety.