Results 191 to 200 of about 48,682 (230)

Coherence degradation in active sonar systems

The Journal of the Acoustical Society of America, 1978
This paper quantifies the degradation in performance of a quadrature receiver when the phase of the input target signal is time-varying and the background noise is additive Gaussian. The quadrature receiver, a conventional signal processor, consists of a replica-correlator followed by a quadratic detector.
R. C. Higgins, J. T. Francis, J. G. Kelly   +2 more
openaire   +1 more source

Active listening in passive-sonar soundscapes

The Journal of the Acoustical Society of America, 2006
Listening tasks differ across a variety of dimensions. Tasks that are characteristic of competing channels are those in which command and control signals are delivered simultaneously. Such signals are typically highly uncertain, statistically independent, and nonredundant. Tasks that are characteristic of cooperative channels are those in which sources
Gregory Wakefield, Thomas Santoro
openaire   +1 more source

Adaptive waveform selection for active sonar

Proceedings of ICASSP '94. IEEE International Conference on Acoustics, Speech and Signal Processing, 2002
Investigates an adaptive waveform selection scheme where selection is based on overall tracking performance of the active sonar system. The assumption of an optimal receiver allows the inclusion of transmitted waveform specification parameters in the tracking sub-system equations, leading to a waveform selection scheme where the next transmitted ...
D.J. Kershaw, R.J. Evans
openaire   +1 more source

Characterization of active sonar targets

2018
<p>The problem of characterization of active sonar target response has important applications in many fields, including the currently cost-prohibitive recovery of unexploded ordinance on the ocean floor. We present a method for recognizing these objects using a multidisciplinary approach that fuses machine learning, signal processing, and feature
Daniel Schupp-Omid, Ananya Sen Gupta, Mark Andersland, Anton Kruger   +3 more
openaire   +1 more source

Application of DORT to active sonar

Oceans '04 MTS/IEEE Techno-Ocean '04 (IEEE Cat. No.04CH37600), 2005
Active sonar in shallow water is often reverberation-limited and the detectability is often limited by the presence of too many false alarms. The problem of improving detection, and classification, in shallow water is being worked on in several different ways. The time reversal operator decomposition (DORT) is a technique that has recently been applied
C.F. Gaumond, D.M. Fromm, J. Lingevitch, R. Menis, G. Edelmann, D. Calvo, E. Kim   +6 more
openaire   +1 more source

Interference Mitigation for Multistatic Active Sonar

IEEE Journal of Oceanic Engineering, 2015
Two methods for detecting and classifying mutual interference between sources in multistatic active sonar systems are developed and compared for frequency-modulated transmissions. Both methods compare the output of matched-filtered time-series data using two different waveform replicas: the intended transmit replica and a hypothesized interferer ...
Jason M. Aughenbaugh, Brian R. La Cour, James M. Gelb   +2 more
openaire   +1 more source

Fundamentals of Bistatic Active SONAR

1989
The purpose of this paper is to provide an introduction to bistatic active sonar. We consider only the simplest case of a single source and a single spatially-separated receiver. The extension to multiple sources and receivers is straightforward and involves the same concepts and principles.
openaire   +1 more source

Real-time continuous active sonar processing

OCEANS 2015 - Genova, 2015
This work describes the development of continuous active sonar (CAS) processing at CMRE. The software uses subband processing to achieve a faster update rate than is possible with pulsed active sonar (PAS). The software development was based on CMRE's PAS processing software, CAINPro, which has been thoroughly tested during previous sea trials and in ...
Gaetano Canepa, Andrea Munafo, Michele Micheli, Luca Morlando, Stefan Murphy   +4 more
openaire   +1 more source

Modern, active sonar AGC design considerations

ICASSP '84. IEEE International Conference on Acoustics, Speech, and Signal Processing, 1984
The following identifies key elements of the AGC design problem for active sonars. Because the character of the background noise and of the echo are highly dependent on a sonar environment that varies from place to place and from hour to hour, the signal statistics are unknown. Researchers have left the area of AGC design to practitioners; such designs
openaire   +1 more source

Active Sonar Target Channel

2022
Junying Hui, Xueli Sheng
openaire   +1 more source