Browsing Technical Reports by Subject "Shallow water"
Now showing items 1-20 of 36
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Acoustic bottom characterization of a shallow water area west of Mallorca
(NATO. SACLANTCEN, 1995/12)An experiment was conducted in shallow water on the Balearic Shelf -
Acoustic bottom reflectivity
(NATO. SACLANTCEN, 1989/06)Acoustic reflectivity from the seafloor is often an important factor influencing the performance of ASW systems in different environments, such as in deep water when the bottom bounce paths are used, and in general in ... -
Active signal detection in shallow water using the Page test
(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 acoustic, high resolution, sediment profiler
(NATO. SACLANTCEN, 1966/11)An acoustic sediment profiler is described that utilizes short 50 kHz pulses to achieve a high range resolution. In trials in shallow water, penetration depths of about 9 m and resolution of about 25 cm were obtained. ... -
An analytical study of source localization in shallow water by matched-field processing of horizontal arrays
(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 ... -
Bathymetric imaging with wideband interferometric synthetic aperture sonar
(NATO. SACLANTCEN, 2001/11)A new approach to interferometric sonar is presented, based on time delay estimation using shortterm correlation of the seafloor backscatter. It is most suited to signals with large relative bandwidths and long interferometric ... -
Bottom reverberation in shallow water: coherent properties as a function of bandwidth, waveguide characteristics and scatterer distribution
(NATO. SACLANTCEN, 1998/10)Scattering physics are often modeled using the Helmholtz equation for computational reasons. Likewise, propagation loss to and from scattering regions are often treated in a like manner. The usual approach for generating ... -
Bottom scattering measurements in shallow water
(NATO. SACLANTCEN, 1999/08)Sonar performance predictions of reverberation in shallow water rely upon good estimates of the bottom scattering strength. However, little is understood about bottom scattering in shallow water in -
Broad-band geoacoustic inversion in shallow water from waveguide response measurements on a single hydrophone: theory and YELLOW SHARK experimental results
(NATO. SACLANTCEN, 1999/05)Executive summary: Performance models such as the Allied Environmental Support System (AESS) require environmental input parameters such as the geoacoustic properties of the battlespace. The models ingest the input parameters ... -
Broadband signal simulation in shallow water
(NATO. SACLANTCEN, 2002/12)Today's minimum requirements for ocean acoustic models are to be able to simulate broadband signal transmissions in 2D varying environments with an acceptable computational effort. Standard -
Channel sensitive processor: real data processing
(NATO. SACLANTCEN, 1998/02)The CSP is applied to data collected during the DUSS97 sea trial. A one-way geometry is used and the transmitted signal propagation time is known a priori. As predicted by analytical and simulation studies, the CSP detector ... -
Deconvolution by homomorphic and Wiener filtering
(NATO. SACLANTCEN, 1988/09)This study is concerned with deconvolution methods applied to underwater propagation in shallow -
Deployable underwater surveillance systems: analysis of experimental results: part III
(NATO. SACLANTCEN, 1999/04)Deployable Underwater Surveillance Systems (DUSS) are a new active sonar concept based on a distributed network of small multistatic transmitter / receiver nodes. This study analyzes data acquired during the period 29 June ... -
Generic Oceanographic Array Technologies (GOATS)'98: bi-static seabed scattering measurements using autonomous underwater vehicles
(NATO. SACLANTCEN, 1998/10)The GOATS'98 experiment was performed May 5-29, 1998 in shallow water off Marciana Marina, on the island of Elba, Italy. The experiment addressed some of the fundamental issues associated with using the new Autonomous Ocean ... -
Geoenvironmental characterization of selected shallow-water sites on the western European continental shelf (SWAP)
(NATO. SACLANTCEN, 1995/04)Geoenvironrnental analyses for four experiment sites on the continental -
High resolution geoacoustic inversion in shallow water: a joint time and frequency domain technique
(NATO. SACLANTCEN, 1998/12)High resolution geoacoustic data are quired for accurate predictions of -
High-resolution characterization of shallow water sea bottom: need and methodology for a ground-truth reference database
(NATO. SACLANTCEN, 1994/12)A systematic approach to underwater observation of high-resolution seabed features has been developed. These include: morphology caused by current, wave, and biological factors and certain engineering geological factors ... -
Horizontal array gain in shallow water
(NATO. SACLANTCEN, 1980/12)Some results of a comprehensive model study on the use of horizontal hydrophone arrays in shallow water are presented. Well-known signal processing techniques are applied to a shallow-water sound propagation model in order ... -
Impact of uncertain environmental knowledge on the shallow-water transfer function
(NATO. SACLANTCEN, 1992/12)It is assumed that the acoustic channel can be modeled as a linear time-invariant space-variant filter. In this case, from linear systems theory, it is known that the filter output, that is the predicted source signal ...