Browsing by Author "Abraham, Douglas A."
Now showing items 1-11 of 11
-
Active signal detection in shallow water using the Page test
Abraham, Douglas A.; Willett, Peter K. (NATO. SACLANTCEN, 1996/11)The use of active sonar in shallow water results in received echoes that may be considerably spread in time compared to the transmitted wave form. The duration and structure of the spreading and the time of occurrence of ... -
An analytical study of source localization in shallow water by matched-field processing of horizontal arrays
Abraham, Douglas A. (NATO. SACLANTCEN, 1992/08)Over the last few years a large number of studies have reported results of range-depth localization of sound sources by matched-field processing of vertical arrays in known environments. The performance of matched-field ... -
Analysis of a signal starting time estimator based on the Page test statistic
Abraham, Douglas A. (NATO. SACLANTCEN, 1995/12)The time of the most recent reset to zero of the Page test statistic is proposed as an estimator of the starting time of a signal. The probability mass function of the estimator is determined analytically subject to a ... -
Modeling non-Rayleigh reverberation
Abraham, Douglas A. (NATO. SACLANTCEN, 1997/05)Researchers over the past three decades have experimentally examined non-Rayleigh reverberation, -
Passive acoustic detection of marine mammals
Abraham, Douglas A. (NATO. SACLANTCEN, 2000/04)A passive acoustic analysis of data recorded during the SACLANTCEN -
Probability of false alarm estimation in oversampled active sonar systems
Abraham, Douglas A. (NATO. SACLANTCEN, 1998/08)The probability of false alarm (Pfa)in active sonar systems is an -
Reduction of low frequency active sonar clutter through image processing
Dugelay, S.; Abraham, Douglas A. (NATO. SACLANTCEN, 1997/12)Large numbers of false clutter detections arise in the use of low frequency active sonar for the detection of low Doppler submarine targets in shallow water. Traditional detection algorithms operate individually on each ... -
Statistical evaluation of 80 kHz shallow-water seafloor reverberation
Lyons, Anthony P.; Abraham, Douglas A.; Akal, Tuncay; Guerrini, Piero (NATO. SACLANTCEN, 1997)In this work a comparison is presented between 80 kHz reverberation statistics obtained at shallow water sites around Sardinia and Sicily. The data include measurements from several distinct bottom provinces, including ... -
Statistical evaluation of 80 kHz shallow-water seafloor reverberation
Lyons, Anthony .P.; Abraham, Douglas A.; Akal, Tuncay; Guerrini, Piero (NATO. SACLANTCEN, 1997/09)Knowledge of the background reverberation environment is a prerequisite for the design of any target detection scheme. While the problem of understanding and predicting high-frequency background reverberation level or mean ... -
Statistical normalization of non-Rayleigh reverberation
Abraham, Douglas A. (NATO. SACLANTCEN, 2000/02)Low-frequency active sonar systems operating in shallow water are primarily limited by reverberation. -
Toeplitz constrained adaptive beamforming with auxiliary data
Abraham, Douglas A. (NATO. SACLANTCEN, 1997/02)Submarine and mine detection using active sonar face similar problems when adaptive beamforming is required to provide high angular resolution or to suppress angularly isolated interferences. Both