Low frequency active sonar (Generic UK) performance assessment in the operationally significant area of the Northwest approaches to the United Kingdom
The goal of this research was to make a performance assessment for a generic UK Low Frequency Active Sonar (LFAS) operating in the northwest approaches to the UK. Five diverse and operationally significant sound speed and geoacoustic transects of the region in winter and summer were considered. The...
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Monterey, California. Naval Postgraduate School
1998
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ftnavalpschool:oai:calhoun.nps.edu:10945/8637 2024-06-09T07:48:30+00:00 Low frequency active sonar (Generic UK) performance assessment in the operationally significant area of the Northwest approaches to the United Kingdom Hunt, Charles J. Bourke, Robert H. Wilson, James H. Naval Postgraduate School Oceanography 1998-09-01 xii, 132 p. application/pdf https://hdl.handle.net/10945/8637 en_US eng Monterey, California. Naval Postgraduate School https://hdl.handle.net/10945/8637 Copyright is reserved by the copyright owner Oceanography Propagation loss Low frequency active sonar Performance assessment Northeast Atlantic Inverse beamforming Thesis 1998 ftnavalpschool 2024-05-15T01:05:57Z The goal of this research was to make a performance assessment for a generic UK Low Frequency Active Sonar (LFAS) operating in the northwest approaches to the UK. Five diverse and operationally significant sound speed and geoacoustic transects of the region in winter and summer were considered. The intention was to use an operational, ray theory based, acoustic propagation loss model for the performance assessment at 400 Hz and. 800 Hz for various source/ target depths. Prior to the assessment the ray model was compared with a finite element primitive equation transmission loss model (RAM) to, firstly, validate the propagation loss algorithms, and, secondly, to make any required corrections to the ray model propagation loss output as a result of variable geoacoustic conditions. Results show that the ray model compares favorably with RAM and only minor corrections were required. RAM was also used to evaluate the effect of the South East Icelandic Front in summer on acoustic propagation at the frequencies of interest. Results demonstrate that, depending upon source/receiver dispositions, the inclusion of range dependent sound speed profiles and geoacoustic parameters are a necessity. LFAS performance results demonstrate that the system is able to achieve good results with lower frequencies performing better than high frequencies. However, high reverberation levels are a severe limiting factor. Investigation into advanced signal processing techniques suggest that the utilization of inverse beamforming techniques has the potential to improve detection opportunities by suppressing reverberation. Approved for public release; distribution is unlimited. Lieutenant Commander, United Kingdom Royal Navy http://archive.org/details/lowfrequencyctiv109458637 Thesis Northeast Atlantic Naval Postgraduate School: Calhoun |
institution |
Open Polar |
collection |
Naval Postgraduate School: Calhoun |
op_collection_id |
ftnavalpschool |
language |
English |
topic |
Oceanography Propagation loss Low frequency active sonar Performance assessment Northeast Atlantic Inverse beamforming |
spellingShingle |
Oceanography Propagation loss Low frequency active sonar Performance assessment Northeast Atlantic Inverse beamforming Hunt, Charles J. Low frequency active sonar (Generic UK) performance assessment in the operationally significant area of the Northwest approaches to the United Kingdom |
topic_facet |
Oceanography Propagation loss Low frequency active sonar Performance assessment Northeast Atlantic Inverse beamforming |
description |
The goal of this research was to make a performance assessment for a generic UK Low Frequency Active Sonar (LFAS) operating in the northwest approaches to the UK. Five diverse and operationally significant sound speed and geoacoustic transects of the region in winter and summer were considered. The intention was to use an operational, ray theory based, acoustic propagation loss model for the performance assessment at 400 Hz and. 800 Hz for various source/ target depths. Prior to the assessment the ray model was compared with a finite element primitive equation transmission loss model (RAM) to, firstly, validate the propagation loss algorithms, and, secondly, to make any required corrections to the ray model propagation loss output as a result of variable geoacoustic conditions. Results show that the ray model compares favorably with RAM and only minor corrections were required. RAM was also used to evaluate the effect of the South East Icelandic Front in summer on acoustic propagation at the frequencies of interest. Results demonstrate that, depending upon source/receiver dispositions, the inclusion of range dependent sound speed profiles and geoacoustic parameters are a necessity. LFAS performance results demonstrate that the system is able to achieve good results with lower frequencies performing better than high frequencies. However, high reverberation levels are a severe limiting factor. Investigation into advanced signal processing techniques suggest that the utilization of inverse beamforming techniques has the potential to improve detection opportunities by suppressing reverberation. Approved for public release; distribution is unlimited. Lieutenant Commander, United Kingdom Royal Navy http://archive.org/details/lowfrequencyctiv109458637 |
author2 |
Bourke, Robert H. Wilson, James H. Naval Postgraduate School Oceanography |
format |
Thesis |
author |
Hunt, Charles J. |
author_facet |
Hunt, Charles J. |
author_sort |
Hunt, Charles J. |
title |
Low frequency active sonar (Generic UK) performance assessment in the operationally significant area of the Northwest approaches to the United Kingdom |
title_short |
Low frequency active sonar (Generic UK) performance assessment in the operationally significant area of the Northwest approaches to the United Kingdom |
title_full |
Low frequency active sonar (Generic UK) performance assessment in the operationally significant area of the Northwest approaches to the United Kingdom |
title_fullStr |
Low frequency active sonar (Generic UK) performance assessment in the operationally significant area of the Northwest approaches to the United Kingdom |
title_full_unstemmed |
Low frequency active sonar (Generic UK) performance assessment in the operationally significant area of the Northwest approaches to the United Kingdom |
title_sort |
low frequency active sonar (generic uk) performance assessment in the operationally significant area of the northwest approaches to the united kingdom |
publisher |
Monterey, California. Naval Postgraduate School |
publishDate |
1998 |
url |
https://hdl.handle.net/10945/8637 |
genre |
Northeast Atlantic |
genre_facet |
Northeast Atlantic |
op_relation |
https://hdl.handle.net/10945/8637 |
op_rights |
Copyright is reserved by the copyright owner |
_version_ |
1801380255134384128 |