The AN/UQQ-2 Surveillance Towed Array Sensor System (SURTASS), colloquially referred to as the ship's "Tail", is a towed arraysonar system of the United States Navy.
USNS Invincible as originally configured. Aft view of equipment for the Surveillance Towed-Array Sensor System (SURTASS), 1987.USNS Able (T-AGOS-20) aft view of SURTASS equipment.
SURTASS Twin-Line consists of either the long passive SURTASS array or the Twin-line array, consisting of two shorter passive arrays towed side by side. The Twin-line Engineering Development Model was installed on USNS Assertive, and the first production model was installed on USNS Bold.[1] Neither ship still serve as SURTASS units.
SURTASS began as development program in 1973 using the new research vessel Moana Wave. In 1980 SURTASS passed OPEVAL. The new Stalwart-class ocean surveillance ships had the first contract awarded on 26 September 1980 and were similar to the prototype ship, the Moana Wave. Initially the SURTASS system were passive, receiving only sonar systems. The array was towed miles behind the ships and were designed for long range detection of submarines.
As the passive systems were being deployed, an active adjunct known as the SURTASS Low Frequency Active (LFA) systems was designed for long range detection. The active system must be used in conjunction with the passive received system. The active component transmits an audio signal between 100 Hz and 500 Hz from an array suspended below the ship while the passive SURTASS array is towed miles behind to receive the signal after it had reflected off the submarine. The active LFA system is an updated version of the fixed low frequency surveillance system known as Project Artemis. Although the Navy took steps to mitigate the environmental damage, environmental non-governmental organizations (NGOs) urged the Navy to prepare a public environmental impact statement. In 1996 the Navy published a notice of intent to prepare an environmental impact statement. The Navy has spent over $16 million on scientific research on the effects on marine mammals and mitigation systems as well as the development of an Environmental Impact Statement.[3]
The SURTASS Low Frequency Active Sonar system, on board Impeccable, commenced sea trials in late February 2004. During the spring and summer of 2004, Impeccable conducted five training missions in the Philippine Sea and the northwest Pacific Ocean. All LFA sonar operations included the operation of the High Frequency / Marine Mammal Mitigation sonar and compliance with all mitigation requirements.[4]
Total operational days on board the Impeccable using the LFA array:
(August 15, 2003 to August 15, 2004) 26.2 days with 63.0 hours of transmissions
(August 15, 2004 to August 15, 2005) 9.4 days with 22.7 hours of transmissions
(August 15, 2005 to August 15, 2006) 22.5 days with 39.4 hours of transmissions[5]
SURTASS LFA is a long-range, all-weather, sonar system with both passive and active components, operating in the low frequency (LF) band (100–500 hertz [Hz]). USNS Impeccable has the original LFA system, weighing 155 tonnes; the 64-tonne Compact LFA derivative was developed for the smaller Victorious class. CLFA was installed on Able in 2008, on Effective in 2011 and Victorious in 2012; no further installations are planned.
The active system component, LFA, is an adjunct to the passive detection system, SURTASS, and is planned for use when passive system performance proves inadequate. LFA is a set of acoustic transmitting source elements suspended by cable from underneath a ship. These elements, called projectors, are devices that produce the active sound pulse, or ping. The projectors transform electrical energy to mechanical energy that set up vibrations or pressure disturbances within the water to produce a ping.
The characteristics and operating features of LFA are:
The source is a vertical line array (VLA) of up to 18 source projectors suspended below the vessel. LFA’s transmitted sonar beam is omnidirectional (i.e., a full 360 degrees) in the horizontal (nominal depth of the LFA array center is 120 m [400 ft]), with a narrow vertical beamwidth that can be steered above or below the horizontal.
The source frequency is between 100 and 500 Hz (the LFA system’s physical design does not allow for transmissions below 100 Hz). A variety of signal types can be used, including continuous wave (CW) and frequency-modulated (FM) signals. Signal bandwidth is approximately 30 Hz.
The source level (SL) of an individual source projector is approximately 215 decibels (dB re 1 μPa2 m2).[6]
The typical LFA transmitted sonar signal is not a constant tone, but a transmission of various waveforms that vary in frequency and duration. A complete sequence of transmissions is referred to as a ping and lasts from 6 to 100 seconds, although the duration of each continuous frequency transmission is never longer than 10 seconds.
Duty cycles (ratio of sound “on” time to total time) are less than 20 percent—20 percent is the maximum physical limit of the LFA system. Typical duty cycles are approximately 7.5 to 10 percent.
The time between pings is typically from 6 to 15 minutes.
The passive, or listening, part of the system is SURTASS, which detects returning echoes from submerged objects, such as submarines, through the use of hydrophones. These devices transform mechanical energy (received acoustic sound wave) to an electrical signal that can be analyzed by the signal processing system of the sonar. The SURTASS hydrophones are mounted on a horizontal receive array that is towed behind the vessel. The array length is 1,500 m (4,900 ft) with an operational depth of 150 to 460 m (500 to 1,500 ft). The SURTASS LFA ship must maintain a minimum speed of approximately 6 kilometres per hour (3.2 knots) through the water in order to tow the hydrophone array in the horizontal plane. The return signals or echoes, which are usually below background or ambient noise level, are then processed and evaluated to identify and classify potential underwater targets.[7]
See alsoedit
Sonar 2087, low frequency active sonar fitted to British warships, the CAPTAS4 derivative is being tested by the US Navy
Referencesedit
^. Archived from the original on 2006-11-23. Retrieved 2006-12-28.
^. Archived from the original on 2012-02-05. Retrieved 2006-12-30.
^. Archived from the original on 2013-09-28. Retrieved 2006-12-30.
^"Federal Register: August 25, 2005 (Volume 70, Number 164)".[permanent dead link]
^"SURTASS/LFA Final Report" (PDF). (PDF) from the original on 2017-01-28. Retrieved 2009-03-28.
^M. A. Ainslie, Principles of Sonar Performance Modeling (Springer, 2010), p522
^"SURTASS LFA FINAL REPORT page 9" (PDF). (PDF) from the original on 2017-01-28. Retrieved 2009-03-28.
External linksedit
GlobalSecurity.org
Federation of American Scientists
NOAA National Marine Fisheries Service Office of Protected Resources SURTASS LFA page
SURTASS Twinline and LFA information
March 26, 2024
surveillance, towed, array, sensor, system, surtass, colloquially, referred, ship, tail, towed, array, sonar, system, united, states, navy, usns, invincible, originally, configured, view, equipment, surveillance, towed, array, sensor, system, surtass, 1987, us. The AN UQQ 2 Surveillance Towed Array Sensor System SURTASS colloquially referred to as the ship s Tail is a towed array sonar system of the United States Navy USNS Invincible as originally configured Aft view of equipment for the Surveillance Towed Array Sensor System SURTASS 1987 USNS Able T AGOS 20 aft view of SURTASS equipment SURTASS Twin Line consists of either the long passive SURTASS array or the Twin line array consisting of two shorter passive arrays towed side by side The Twin line Engineering Development Model was installed on USNS Assertive and the first production model was installed on USNS Bold 1 Neither ship still serve as SURTASS units As of 2009 update SURTASS was deployed on the four Victorious class vessels and the USNS Impeccable T AGOS 23 a small waterplane area twin hull SWATH vessel 2 Contents 1 History 2 Description 3 See also 4 References 5 External linksHistory editSURTASS began as development program in 1973 using the new research vessel Moana Wave In 1980 SURTASS passed OPEVAL The new Stalwart class ocean surveillance ships had the first contract awarded on 26 September 1980 and were similar to the prototype ship the Moana Wave Initially the SURTASS system were passive receiving only sonar systems The array was towed miles behind the ships and were designed for long range detection of submarines As the passive systems were being deployed an active adjunct known as the SURTASS Low Frequency Active LFA systems was designed for long range detection The active system must be used in conjunction with the passive received system The active component transmits an audio signal between 100 Hz and 500 Hz from an array suspended below the ship while the passive SURTASS array is towed miles behind to receive the signal after it had reflected off the submarine The active LFA system is an updated version of the fixed low frequency surveillance system known as Project Artemis Although the Navy took steps to mitigate the environmental damage environmental non governmental organizations NGOs urged the Navy to prepare a public environmental impact statement In 1996 the Navy published a notice of intent to prepare an environmental impact statement The Navy has spent over 16 million on scientific research on the effects on marine mammals and mitigation systems as well as the development of an Environmental Impact Statement 3 The SURTASS Low Frequency Active Sonar system on board Impeccable commenced sea trials in late February 2004 During the spring and summer of 2004 Impeccable conducted five training missions in the Philippine Sea and the northwest Pacific Ocean All LFA sonar operations included the operation of the High Frequency Marine Mammal Mitigation sonar and compliance with all mitigation requirements 4 Total operational days on board the Impeccable using the LFA array August 15 2003 to August 15 2004 26 2 days with 63 0 hours of transmissions August 15 2004 to August 15 2005 9 4 days with 22 7 hours of transmissions August 15 2005 to August 15 2006 22 5 days with 39 4 hours of transmissions 5 The ship had five years of active and passive operations in the Western Pacific before an incident in the South China Sea citation needed not specific enough to verify Description editSURTASS LFA is a long range all weather sonar system with both passive and active components operating in the low frequency LF band 100 500 hertz Hz USNS Impeccable has the original LFA system weighing 155 tonnes the 64 tonne Compact LFA derivative was developed for the smaller Victorious class CLFA was installed on Able in 2008 on Effective in 2011 and Victorious in 2012 no further installations are planned The active system component LFA is an adjunct to the passive detection system SURTASS and is planned for use when passive system performance proves inadequate LFA is a set of acoustic transmitting source elements suspended by cable from underneath a ship These elements called projectors are devices that produce the active sound pulse or ping The projectors transform electrical energy to mechanical energy that set up vibrations or pressure disturbances within the water to produce a ping The characteristics and operating features of LFA are The source is a vertical line array VLA of up to 18 source projectors suspended below the vessel LFA s transmitted sonar beam is omnidirectional i e a full 360 degrees in the horizontal nominal depth of the LFA array center is 120 m 400 ft with a narrow vertical beamwidth that can be steered above or below the horizontal The source frequency is between 100 and 500 Hz the LFA system s physical design does not allow for transmissions below 100 Hz A variety of signal types can be used including continuous wave CW and frequency modulated FM signals Signal bandwidth is approximately 30 Hz The source level SL of an individual source projector is approximately 215 decibels dB re 1 mPa2 m2 6 The typical LFA transmitted sonar signal is not a constant tone but a transmission of various waveforms that vary in frequency and duration A complete sequence of transmissions is referred to as a ping and lasts from 6 to 100 seconds although the duration of each continuous frequency transmission is never longer than 10 seconds Duty cycles ratio of sound on time to total time are less than 20 percent 20 percent is the maximum physical limit of the LFA system Typical duty cycles are approximately 7 5 to 10 percent The time between pings is typically from 6 to 15 minutes The passive or listening part of the system is SURTASS which detects returning echoes from submerged objects such as submarines through the use of hydrophones These devices transform mechanical energy received acoustic sound wave to an electrical signal that can be analyzed by the signal processing system of the sonar The SURTASS hydrophones are mounted on a horizontal receive array that is towed behind the vessel The array length is 1 500 m 4 900 ft with an operational depth of 150 to 460 m 500 to 1 500 ft The SURTASS LFA ship must maintain a minimum speed of approximately 6 kilometres per hour 3 2 knots through the water in order to tow the hydrophone array in the horizontal plane The return signals or echoes which are usually below background or ambient noise level are then processed and evaluated to identify and classify potential underwater targets 7 See also editSonar 2087 low frequency active sonar fitted to British warships the CAPTAS4 derivative is being tested by the US NavyReferences edit 2002 Edition Vision Presence Power Archived from the original on 2006 11 23 Retrieved 2006 12 28 Military Sealift Command Ship Inventory Archived from the original on 2012 02 05 Retrieved 2006 12 30 Surtass Lfa Archived from the original on 2013 09 28 Retrieved 2006 12 30 Federal Register August 25 2005 Volume 70 Number 164 permanent dead link SURTASS LFA Final Report PDF Archived PDF from the original on 2017 01 28 Retrieved 2009 03 28 M A Ainslie Principles of Sonar Performance Modeling Springer 2010 p522 SURTASS LFA FINAL REPORT page 9 PDF Archived PDF from the original on 2017 01 28 Retrieved 2009 03 28 External links editUSN SURTASS LFA page GlobalSecurity org Federation of American Scientists NOAA National Marine Fisheries Service Office of Protected Resources SURTASS LFA page SURTASS Twinline and LFA information Moana Wave specifications Retrieved from https en wikipedia org w index php title Surveillance Towed Array Sensor System amp oldid 1181664110, wikipedia, wiki, book, books, library,
