Results 1 - 10 of 241

Analyzing the Real-Time Properties of a U.S. Navy Signal Processing System

by Steve Goddard, Kevin Jeffay - Proc. 4th IEEE Int. Symp. on High Assurance Systems Engineering , 1999
"... The state of the art in verifying the real-time requirements of applications developed using general processing graph models relies on simulation or off-line scheduling. We extend the state of the art by presenting analytical methods that support the analysis of cyclic processing graphs executed wit ..."
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per execution on a given processor, the resulting CPU utilization can be computed, as shown here for the Directed Low Frequency Analysis and Recording (DIFAR) acoustic signal processing application from the Airborne Low Frequency Sonar (ALFS) system of the SH-60B LAMPS MK III anti-submarine helicopter

LABORATORY MODEL OF HIGH FREQUENCY SONAR

by Krystian Buszman, Wojciech Szymczak
"... This article contains the construction and laboratory application of high frequency sonar model. In view of working in laboratory conditions, they must be fulfilled succeeding parametric cases: very narrow beam, low level of side lobes and low acoustic power of transmitted impulse sounding. When all ..."
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This article contains the construction and laboratory application of high frequency sonar model. In view of working in laboratory conditions, they must be fulfilled succeeding parametric cases: very narrow beam, low level of side lobes and low acoustic power of transmitted impulse sounding. When

DEPLOYABLE SONAR SYSTEMS FOR UNDERWATER COMMUNICATIONS

by S. Eswar Prasad, Richard Blacow, Jeffrey Frank, David Waechter
"... Abstract: This paper describes deployable underwater acoustic systems developed by Sensor Technology Limited. Two of these systems are based on a low-frequency barrel stave projector and a third one on a higher frequency transducer operating at 24kHz. The three systems are the Broadband Acoustic Tra ..."
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Abstract: This paper describes deployable underwater acoustic systems developed by Sensor Technology Limited. Two of these systems are based on a low-frequency barrel stave projector and a third one on a higher frequency transducer operating at 24kHz. The three systems are the Broadband Acoustic

ACTIVE SONAR & BEAKED WHALES

by Michel Andre, Peter Evans, Heidrun Frisch, Re Gannier, Jonathan Gordon, Mark Johnson, Irini Papanicolopulu, Simone Panigada, Peter Tyack, Andrew Wright , 2009
"... There is evidence that active sonar exposure can have significant impacts on some cetacean species at relatively low levels (Evans and England, 2003; Evans and Miller, 2004). Beaked whales in particular are vulnerable to serious impacts including mortality from exposure to mid-frequency active sonar ..."
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There is evidence that active sonar exposure can have significant impacts on some cetacean species at relatively low levels (Evans and England, 2003; Evans and Miller, 2004). Beaked whales in particular are vulnerable to serious impacts including mortality from exposure to mid-frequency active

Synthetic Aperture Sonar Low Frequency vs. High Frequency Automatic Contact Generation

by J. R. Dubberley, M. L. Gendron
"... Abstract- Synthetic Aperture Sonar (SAS) bottom mapping sensors are on the verge of entering operational use. Here we examine the utility of both the low and high frequency output of SAS systems recorded from trials to determine their utility in the automatic contact generation scheme described in t ..."
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Abstract- Synthetic Aperture Sonar (SAS) bottom mapping sensors are on the verge of entering operational use. Here we examine the utility of both the low and high frequency output of SAS systems recorded from trials to determine their utility in the automatic contact generation scheme described

Comparison Of Chirp Scaling and wavenumber Domain Algorithms For Airborne Low frequency

by A. Potsis, A. Reigber, A. Moreira, L. Ferro-famil, N. Uzunoglou - SAR Data Processing”, Proc. SPIE
"... In recent years a new class of Synthetic Aperture Ra-dar (SAR) systems using low frequency have emerged. The combination of low frequency with high bandwidth allows a variety of new applications. Several new fields arise in forestry, biomass measuring and in archaeological and geological exploration ..."
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algorithms are proposed, which optimise the respective algorithm for processing low frequency, wide-beam and wide-band SAR data. The analysis is per-formed using simulated low frequency airborne SAR data. 1

A Low-Frequency Sonar for SensorAdaptive, Multistatic, Detection and Classification of Underwater Targets with AUVs

by Donald P. Eickstedt, Henrik Schmidt - Proc. Oceans , 2003
"... development of sensor-adaptive autonomous underwater vehicle (AUV) technology specifically directed toward rapid environmental assessment and mine countermeasures in coastal environments. As part of the effort, MIT is developing the GOATS multi-static sonar concept with the goal of being able to det ..."
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to detect and classify targets on and within the seabed in very shallow water. To support this project, a high performance, multi-channel sonar was developed as a payload for the Odyssey-III class AUVs used by MIT and a number of other institutions. This sonar payload is capable of low/mid frequency target

Smart Structure Active Sonar Echo Cancellation Using Frequency Scheduled Control

by Laurence R. Riddle, John J. Murray
"... Practical applications of smart structure technology to active acoustic noise control demand high performance at low cost. Typically, performance increases achieved by reducing control system latency are expensive. Furthermore, sonar echo cancellation is concerned with a wide frequency range for whi ..."
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Practical applications of smart structure technology to active acoustic noise control demand high performance at low cost. Typically, performance increases achieved by reducing control system latency are expensive. Furthermore, sonar echo cancellation is concerned with a wide frequency range

Application of Mobile Dual-frequency Identification Sonar (DIDSON) to Fish in Estuarine Habitats

by K W Able , T M Grothues , J L Rackovan , F E Buderman
"... Abstract -Dual-frequency identification sonar (DIDSON) offers important advantages over other sampling tools for observing pelagic and benthic fishes in situ. Because it relies on sound, DIDSON can detect fish in a non-destructive and non-intrusive manner. In our unique application, the equipment&a ..."
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Abstract -Dual-frequency identification sonar (DIDSON) offers important advantages over other sampling tools for observing pelagic and benthic fishes in situ. Because it relies on sound, DIDSON can detect fish in a non-destructive and non-intrusive manner. In our unique application, the equipment

Airborne gravimetry: An investigation of filtering

by Vicki A. Childers, Robin E. Bell, John M. Brozena - Geophysics , 1999
"... Low-pass filtering in airborne gravimetry data pro-cessing plays a fundamental role in determining the spec-tral content and amplitude of the free-air anomaly. Tra-ditional filters used in airborne gravimetry, the 6 x 20-s resistor-capacitor (RC) filter and the 300-s Gaussian fil-ter, heavily attenu ..."
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evaluates low-pass fil-tering options and presents a survey-specific frequency domain filter that employs the fast Fourier transform (FFT) for airborne gravity data. This study recommends a new approach to low-pass filtering airborne data. For a given survey, the filter is
Results 1 - 10 of 241