Keith E Brown - Academia.edu (original) (raw)
Papers by Keith E Brown
ArXiv, 2019
One way to recognise an object is to study how the echo has been shaped during the interaction wi... more One way to recognise an object is to study how the echo has been shaped during the interaction with the target. Wideband sonar allows the study of the energy distribution for a large range of frequencies. The frequency distribution contains information about an object, including its inner structure. This information is a key for automatic recognition. The scattering by a target can be quantitatively described by its Form Function. The Form Function can be calculated based on the data of the initial pulse, reflected pulse and parameters of a medium where the pulse is propagating. In this work spherical objects are classified based on their filler material - water or air. We limit the study to spherical 2 layered targets immersed in water. The Form Function is used as a descriptor and fed into a Neural Network classifier, Multilayer Perceptron (MLP). The performance of the classifier is compared with Support Vector Machine (SVM) and the Form Function descriptor is examined in contrast...
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IEEE Journal of Oceanic Engineering, 2017
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Autonomous Robots, 2016
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2011 17th International Conference on Digital Signal Processing (DSP), 2011
ABSTRACT Sonar was invented by copying bats’ and dolphins’ echolocation systems, but the dominant... more ABSTRACT Sonar was invented by copying bats’ and dolphins’ echolocation systems, but the dominant approaches taken to sonar systems today tend to focus on imagery and resolution. In this paper we explore a bio-inspired approach to sonar and sonar signal processing. Conventional sonars use narrowband pulses. The bio-mimetic pulses developed for this work are based on studies of dolphins echolocation clicks and cover a large frequency band. Classical sonar systems only provide the amplitude of the backscattered echo and consequently classical sonar signal processing is focused on amplitude. In fact much more information concerning the target is hidden in the phase and, working with the wideband bio-mimetic pulses, we describe new methods to extract highly discriminant features. Our approach is demonstrated by applying these techniques in an ATR (automatic target recognition) trial in a real environment. part of the information within is lost. In this paper we present our version of a bio-mimetic sonar: the out-going pulse is based on clicks used by dolphins during echolocation and the backscattered echo is analysed from a signal processing, pattern recognition perspective. The paper is organised as follows: In section 2 we discuss the capabilities of the dolphins’ sonar to understand why their sonars are so efficient in comparison with man-made systems. In section 3 we show how the structure of the dolphins’ echolocation clicks can be interpreted using the fractional Fourier transform and derive from this analysis a model for bio-inspired pulses. We then introduce a feature extraction technique for broadband echoes. Finally we describe an application of the BioSonar for automatic target recognition (ATR) and present the results of an ATR trial completed in March 2010 in a real world environment.
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OCEANS 2009-EUROPE, 2009
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Lecture Notes in Computer Science, 2013
ABSTRACT The sonar of dolphins has developed over many years of evolution and has achieved excell... more ABSTRACT The sonar of dolphins has developed over many years of evolution and has achieved excellent performance levels. With this inspiration, wideband acoustic methods for underwater sensing are being developed. In this paper we explore what we expect to gain from the wide bio-inspired beampattern of such a sonar. The system employed here (the BioSonar) uses wideband sensors based on dolphin sonar, covering a frequency band from around 30kHz to 150kHz and having a frequency dependent beamwidth considerably larger than that of conventional imaging sonars. We highlight the benefits of the transducers' beamwidth, indicating how these properties may be exploited to give improved sonar performance.
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Background In a military setting, classifi cation of radio communication signal can be important ... more Background In a military setting, classifi cation of radio communication signal can be important both as an input to the ongoing situation evaluation and for the selection of appropriate EW countermeasures. Traditionally, trained operators have manually carried out these tasks. However, with the increased use of digital communications, time and automation aspects become more and more crucial. Methods for automated signal classifi cation have been extensively researched in the last few decades.
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The Journal of the Acoustical Society of America, 2011
Recent developments in the understanding and application of wideband bio-inspired acoustic sensor... more Recent developments in the understanding and application of wideband bio-inspired acoustic sensors are enabling new applications of autonomous underwater vehicles (AUVs) for security and oilfield use. Appropriate use of wideband signals has enabled improved discrimination between natural and man-made objects that have physically similar appearance, as well as the detection of buried and partially buried objects. Wideband sonar developments in the Ocean Systems Laboratory at Heriot-Watt University have focused on prototypes based on the bottlenose dolphin sonar, covering a frequency band from around 30 to 150 kHz and having a frequency dependent beam-width that is, considerably larger than conventional imaging sonars. In parallel, AUV technology has developed to allow much greater levels of autonomy in allowable vehicle behavior. New generations of vehicle have moved beyond switching of pre-programmed scripts (behaviors) and their parameters, to systems that interleave planning and e...
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The Journal of the Acoustical Society of America, 2008
The use of autonomous underwater vehicles (AUVs) for a variety of purposes is set to increase in ... more The use of autonomous underwater vehicles (AUVs) for a variety of purposes is set to increase in the future. A key issue in the navigation processing, especially for survey applications, is the lack of accuracy or cumulative error introduced by the various position sensors: accelerometer; DVL; compass. Algorithms such as SLAM (simultaneous localisation and mapping) rely on accurate landmark recognition in order to correct the vehicle position. This paper proposes a solution based on broadband sonar and artificial coded landmarks to improve the navigation. Through resolution of the wave equation for acoustic propagation in a multilayer concentric sphere, we will show that there is a great diversity in the echo spectrum with small changes in internal structure. This enables the design of a set of passive landmarks which can be identified unambiguously, since each has a characteristic signature or 'spectral code' when insonified with a broadband sonar.
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IEEE Transactions on Knowledge and Data Engineering, 2011
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Semantic knowledge-based framework to improve the situation awareness of autonomous
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ArXiv, 2019
One way to recognise an object is to study how the echo has been shaped during the interaction wi... more One way to recognise an object is to study how the echo has been shaped during the interaction with the target. Wideband sonar allows the study of the energy distribution for a large range of frequencies. The frequency distribution contains information about an object, including its inner structure. This information is a key for automatic recognition. The scattering by a target can be quantitatively described by its Form Function. The Form Function can be calculated based on the data of the initial pulse, reflected pulse and parameters of a medium where the pulse is propagating. In this work spherical objects are classified based on their filler material - water or air. We limit the study to spherical 2 layered targets immersed in water. The Form Function is used as a descriptor and fed into a Neural Network classifier, Multilayer Perceptron (MLP). The performance of the classifier is compared with Support Vector Machine (SVM) and the Form Function descriptor is examined in contrast...
Bookmarks Related papers MentionsView impact
IEEE Journal of Oceanic Engineering, 2017
Bookmarks Related papers MentionsView impact
Autonomous Robots, 2016
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2011 17th International Conference on Digital Signal Processing (DSP), 2011
ABSTRACT Sonar was invented by copying bats’ and dolphins’ echolocation systems, but the dominant... more ABSTRACT Sonar was invented by copying bats’ and dolphins’ echolocation systems, but the dominant approaches taken to sonar systems today tend to focus on imagery and resolution. In this paper we explore a bio-inspired approach to sonar and sonar signal processing. Conventional sonars use narrowband pulses. The bio-mimetic pulses developed for this work are based on studies of dolphins echolocation clicks and cover a large frequency band. Classical sonar systems only provide the amplitude of the backscattered echo and consequently classical sonar signal processing is focused on amplitude. In fact much more information concerning the target is hidden in the phase and, working with the wideband bio-mimetic pulses, we describe new methods to extract highly discriminant features. Our approach is demonstrated by applying these techniques in an ATR (automatic target recognition) trial in a real environment. part of the information within is lost. In this paper we present our version of a bio-mimetic sonar: the out-going pulse is based on clicks used by dolphins during echolocation and the backscattered echo is analysed from a signal processing, pattern recognition perspective. The paper is organised as follows: In section 2 we discuss the capabilities of the dolphins’ sonar to understand why their sonars are so efficient in comparison with man-made systems. In section 3 we show how the structure of the dolphins’ echolocation clicks can be interpreted using the fractional Fourier transform and derive from this analysis a model for bio-inspired pulses. We then introduce a feature extraction technique for broadband echoes. Finally we describe an application of the BioSonar for automatic target recognition (ATR) and present the results of an ATR trial completed in March 2010 in a real world environment.
Bookmarks Related papers MentionsView impact
OCEANS 2009-EUROPE, 2009
Bookmarks Related papers MentionsView impact
Lecture Notes in Computer Science, 2013
ABSTRACT The sonar of dolphins has developed over many years of evolution and has achieved excell... more ABSTRACT The sonar of dolphins has developed over many years of evolution and has achieved excellent performance levels. With this inspiration, wideband acoustic methods for underwater sensing are being developed. In this paper we explore what we expect to gain from the wide bio-inspired beampattern of such a sonar. The system employed here (the BioSonar) uses wideband sensors based on dolphin sonar, covering a frequency band from around 30kHz to 150kHz and having a frequency dependent beamwidth considerably larger than that of conventional imaging sonars. We highlight the benefits of the transducers' beamwidth, indicating how these properties may be exploited to give improved sonar performance.
Bookmarks Related papers MentionsView impact
Background In a military setting, classifi cation of radio communication signal can be important ... more Background In a military setting, classifi cation of radio communication signal can be important both as an input to the ongoing situation evaluation and for the selection of appropriate EW countermeasures. Traditionally, trained operators have manually carried out these tasks. However, with the increased use of digital communications, time and automation aspects become more and more crucial. Methods for automated signal classifi cation have been extensively researched in the last few decades.
Bookmarks Related papers MentionsView impact
The Journal of the Acoustical Society of America, 2011
Recent developments in the understanding and application of wideband bio-inspired acoustic sensor... more Recent developments in the understanding and application of wideband bio-inspired acoustic sensors are enabling new applications of autonomous underwater vehicles (AUVs) for security and oilfield use. Appropriate use of wideband signals has enabled improved discrimination between natural and man-made objects that have physically similar appearance, as well as the detection of buried and partially buried objects. Wideband sonar developments in the Ocean Systems Laboratory at Heriot-Watt University have focused on prototypes based on the bottlenose dolphin sonar, covering a frequency band from around 30 to 150 kHz and having a frequency dependent beam-width that is, considerably larger than conventional imaging sonars. In parallel, AUV technology has developed to allow much greater levels of autonomy in allowable vehicle behavior. New generations of vehicle have moved beyond switching of pre-programmed scripts (behaviors) and their parameters, to systems that interleave planning and e...
Bookmarks Related papers MentionsView impact
The Journal of the Acoustical Society of America, 2008
The use of autonomous underwater vehicles (AUVs) for a variety of purposes is set to increase in ... more The use of autonomous underwater vehicles (AUVs) for a variety of purposes is set to increase in the future. A key issue in the navigation processing, especially for survey applications, is the lack of accuracy or cumulative error introduced by the various position sensors: accelerometer; DVL; compass. Algorithms such as SLAM (simultaneous localisation and mapping) rely on accurate landmark recognition in order to correct the vehicle position. This paper proposes a solution based on broadband sonar and artificial coded landmarks to improve the navigation. Through resolution of the wave equation for acoustic propagation in a multilayer concentric sphere, we will show that there is a great diversity in the echo spectrum with small changes in internal structure. This enables the design of a set of passive landmarks which can be identified unambiguously, since each has a characteristic signature or 'spectral code' when insonified with a broadband sonar.
Bookmarks Related papers MentionsView impact
IEEE Transactions on Knowledge and Data Engineering, 2011
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Semantic knowledge-based framework to improve the situation awareness of autonomous
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