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Sample records for active sonar mfas

  1. 75 FR 79342 - Taking and Importing Marine Mammals; Navy Training Activities Conducted Within the Northwest...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-20

    ... exposing them to sound from mid-frequency or high frequency active sonar (MFAS/HFAS) or to underwater... frequency active sonar (MFAS/HFAS) or underwater detonations. After submitting supplemental...

  2. 50 CFR 216.170 - Specified activity and specified geographical region.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... incidental to the following activities: (1) The use of the following mid-frequency active sonar (MFAS) and high frequency active sonar (HFAS) sources, or similar sources, for Navy training activities (estimated amounts below): (1) The use of the following mid-frequency active sonar (MFAS) and high frequency...

  3. 50 CFR 218.100 - Specified activity and specified geographical area.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... active sonar (MFAS) and high frequency active sonar (HFAS) sources, or similar sources, for Navy training...-53 (hull-mounted active sonar)—up to 10865 hours over the course of 5 years (an average of 2173 hours per year); (ii) AN/SQS-56 (hull-mounted active sonar)-up to 705 hours over the course of 5 years...

  4. 50 CFR 218.100 - Specified activity and specified geographical area.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... active sonar (MFAS) and high frequency active sonar (HFAS) sources, or similar sources, for Navy training...-53 (hull-mounted active sonar)—up to 10865 hours over the course of 5 years (an average of 2173 hours per year); (ii) AN/SQS-56 (hull-mounted active sonar)-up to 705 hours over the course of 5 years...

  5. 50 CFR 216.270 - Specified activity and specified geographical region.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... the following mid-frequency active sonar (MFAS) and high frequency active sonar (HFAS) sources, or...) (estimated amounts below): (i) AN/SQS-53 (hull-mounted active sonar)—up to 9885 hours over the course of 5 years (an average of 1977 hours per year) (ii) AN/SQS-56 (hull-mounted active sonar)—up to 2470...

  6. 50 CFR 218.110 - Specified activity and specified geographical area.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... sonar (MFAS) and high frequency active sonar (HFAS) sources, or similar sources, for Navy training...-53 (hull-mounted active sonar)—up to 215 hours over the course of 5 years (an average of 43 hours per year); (ii) AN/SQS-56 (hull-mounted active sonar)—up to 325 hours over the course of 5 years...

  7. 50 CFR 218.110 - Specified activity and specified geographical area.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... sonar (MFAS) and high frequency active sonar (HFAS) sources, or similar sources, for Navy training...-53 (hull-mounted active sonar)—up to 215 hours over the course of 5 years (an average of 43 hours per year); (ii) AN/SQS-56 (hull-mounted active sonar)—up to 325 hours over the course of 5 years...

  8. 50 CFR 216.240 - Specified activity and specified geographical region.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Active Sonar Training (AFAST) § 216.240 Specified activity and specified geographical region. (a... Navy is only authorized if it occurs incidental to the use of the following mid-frequency active sonar (MFAS) sources, high frequency active sonar (HFAS) sources, explosive sonobuoys, or similar sources,...

  9. 50 CFR 216.240 - Specified activity and specified geographical region.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Active Sonar Training (AFAST) § 216.240 Specified activity and specified geographical region. (a... Navy is only authorized if it occurs incidental to the use of the following mid-frequency active sonar (MFAS) sources, high frequency active sonar (HFAS) sources, explosive sonobuoys, or similar sources,...

  10. 50 CFR 216.170 - Specified activity and specified geographical region.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-frequency active sonar (MFAS) and high frequency active sonar (HFAS) sources for U.S. Navy anti-submarine... torpedoes per year) (vi) AN/BQQ-10 (submarine mounted sonar)—up to 1000 hours over the course of 5 years...

  11. 50 CFR 218.120 - Specified activity and geographical area.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the following mid-frequency active sonar (MFAS) sources, high-frequency active sonar (HFAS) sources...-mounted active sonar)—up to 2,890 hours over the course of 5 years (an average of 578 hours per year); (ii) AN/SQS-56 (hull-mounted active sonar)—up to 260 hours over the course of 5 years (an average of...

  12. 50 CFR 218.120 - Specified activity and geographical area.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... the following mid-frequency active sonar (MFAS) sources, high-frequency active sonar (HFAS) sources...-mounted active sonar)—up to 2,890 hours over the course of 5 years (an average of 578 hours per year); (ii) AN/SQS-56 (hull-mounted active sonar)—up to 260 hours over the course of 5 years (an average of...

  13. 3S2: Behavioral Response Studies of Cetaceans to Naval Sonar Signals in Norwegian Waters

    DTIC Science & Technology

    2011-09-30

    species of whales : bottlenose whales , minke whales , and humpback whales to Low Frequency Active Sonar (LFAS) and Mid Frequency Active Sonar (MFAS...our goal is to conduct experiments to test the effectiveness of ramp-up in humpback whales . OBJECTIVES In this research project, our...study of the effectiveness of ramp-up as a mitigation method with abundant and relatively easy-to-study humpback whales , Megaptera novaeangliae; 3

  14. 50 CFR 218.120 - Specified activity and geographical area.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... paragraph (b) of this section and that occur incidental to the activities described in paragraph (c) of this.... long.; 57°16′ N. lat., 151°00′ W. long.; and 55°30′ N. lat., 142°00′ W. long. (c) The taking of marine... the following mid-frequency active sonar (MFAS) sources, high-frequency active sonar (HFAS)...

  15. 50 CFR 218.120 - Specified activity and geographical area.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... paragraph (b) of this section and that occur incidental to the activities described in paragraph (c) of this.... long.; 57°16′ N. lat., 151°00′ W. long.; and 55°30′ N. lat., 142°00′ W. long. (c) The taking of marine... the following mid-frequency active sonar (MFAS) sources, high-frequency active sonar (HFAS)...

  16. Predicting the Environmental Impact of Active Sonar

    NASA Astrophysics Data System (ADS)

    Duncan, Alec J.; McCauley, Robert D.; Maggi, Amos L.

    2004-11-01

    The effect of active sonar on marine animals, particularly mammals, has become a hot topic in recent times. The Australian Environmental Protection and Biodiversity Conservation Act 1999 obligates Defence to avoid significant environmental impacts from Navy activities including those which produce underwater sound such as active sonar. It is in the interests of all parties that these effects be modeled accurately to facilitate both the quantitative evaluation of the consequences of any proposed sonar trials, and the identification of suitable mitigation procedures. This paper discusses the received signal parameters that are of importance when predicting the effect of sonar systems on marine animals and techniques for modeling both the expected values of these parameters and their statistical fluctuations.

  17. 50 CFR 216.270 - Specified activity and specified geographical region.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... the activities described in paragraph (c) of this section. (b) The taking of marine mammals by the.... lat.; 127°10′04″ W. long. and 24°00′01″ N. lat.; 125°00′03″ W. long. (c) The taking of marine mammals... the following mid-frequency active sonar (MFAS) and high frequency active sonar (HFAS) sources,...

  18. 50 CFR 216.270 - Specified activity and specified geographical region.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... the activities described in paragraph (c) of this section. (b) The taking of marine mammals by the.... lat.; 127°10′04″ W. long. and 24°00′01″ N. lat.; 125°00′03″ W. long. (c) The taking of marine mammals... the following mid-frequency active sonar (MFAS) and high frequency active sonar (HFAS) sources,...

  19. 50 CFR 218.110 - Specified activity and specified geographical area.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... paragraph (c) of this section. (b) The taking of marine mammals by the Navy is only authorized if it occurs... not included in the Offshore area). (c) The taking of marine mammals by the Navy is only authorized if... the following mid-frequency active sonar (MFAS) sources, high frequency active sonar (HFAS)...

  20. Changes in dive behavior during naval sonar exposure in killer whales, long-finned pilot whales, and sperm whales.

    PubMed

    Sivle, L D; Kvadsheim, P H; Fahlman, A; Lam, F P A; Tyack, P L; Miller, P J O

    2012-01-01

    Anthropogenic underwater sound in the environment might potentially affect the behavior of marine mammals enough to have an impact on their reproduction and survival. Diving behavior of four killer whales (Orcinus orca), seven long-finned pilot whales (Globicephala melas), and four sperm whales (Physeter macrocephalus) was studied during controlled exposures to naval sonar [low frequency active sonar (LFAS): 1-2 kHz and mid frequency active sonar (MFAS): 6-7 kHz] during three field seasons (2006-2009). Diving behavior was monitored before, during and after sonar exposure using an archival tag placed on the animal with suction cups. The tag recorded the animal's vertical movement, and additional data on horizontal movement and vocalizations were used to determine behavioral modes. Killer whales that were conducting deep dives at sonar onset changed abruptly to shallow diving (ShD) during LFAS, while killer whales conducting deep dives at the onset of MFAS did not alter dive mode. When in ShD mode at sonar onset, killer whales did not change their diving behavior. Pilot and sperm whales performed normal deep dives (NDD) during MFAS exposure. During LFAS exposures, long-finned pilot whales mostly performed fewer deep dives and some sperm whales performed shallower and shorter dives. Acoustic recording data presented previously indicates that deep diving (DD) is associated with feeding. Therefore, the observed changes in dive behavior of the three species could potentially reduce the foraging efficiency of the affected animals.

  1. Changes in dive behavior during naval sonar exposure in killer whales, long-finned pilot whales, and sperm whales

    PubMed Central

    Sivle, L. D.; Kvadsheim, P. H.; Fahlman, A.; Lam, F. P. A.; Tyack, P. L.; Miller, P. J. O.

    2012-01-01

    Anthropogenic underwater sound in the environment might potentially affect the behavior of marine mammals enough to have an impact on their reproduction and survival. Diving behavior of four killer whales (Orcinus orca), seven long-finned pilot whales (Globicephala melas), and four sperm whales (Physeter macrocephalus) was studied during controlled exposures to naval sonar [low frequency active sonar (LFAS): 1–2 kHz and mid frequency active sonar (MFAS): 6–7 kHz] during three field seasons (2006–2009). Diving behavior was monitored before, during and after sonar exposure using an archival tag placed on the animal with suction cups. The tag recorded the animal's vertical movement, and additional data on horizontal movement and vocalizations were used to determine behavioral modes. Killer whales that were conducting deep dives at sonar onset changed abruptly to shallow diving (ShD) during LFAS, while killer whales conducting deep dives at the onset of MFAS did not alter dive mode. When in ShD mode at sonar onset, killer whales did not change their diving behavior. Pilot and sperm whales performed normal deep dives (NDD) during MFAS exposure. During LFAS exposures, long-finned pilot whales mostly performed fewer deep dives and some sperm whales performed shallower and shorter dives. Acoustic recording data presented previously indicates that deep diving (DD) is associated with feeding. Therefore, the observed changes in dive behavior of the three species could potentially reduce the foraging efficiency of the affected animals. PMID:23087648

  2. Enhanced Multistatic Active Sonar via Innovative Signal Processing

    DTIC Science & Technology

    2015-09-30

    Grove, CA, November, 2014. [in press, refereed]. C . Gianelli, L. Xu, and J. Li, " Active Sonar Systems in the Presence of Strong Direct Blast", Oceans...3. DATES COVERED (From - To) Oct. 01, 2014-Sept. 30, 2015 4. TITLE AND SUBTITLE Enhanced Multistatic Active Sonar via Innovative Signal... active sonar (CAS) in the presence of strong direct blast is studied for the Doppler-tolerant linear frequency modulation waveform. A receiver design

  3. Enhanced Multistatic Active Sonar via Innovative Signal Processing

    DTIC Science & Technology

    2014-09-30

    DATES COVERED (From - To) Oct. 01. 2013-Sept. 30, 2014 4. TITLE AND SUBTITLE Enhanced Multistatic Active Sonar via Innovative Signal Processing 5a...DISTRIBUTION AVAILABILITY STATEMENT Approved for Public Release; Distribution is Unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT Pulsed active sonar ...PAS) and continuous active sonar (CAS) in the presence of strong direct blast are studied for the Doppler-tolerant linear frequency modulation

  4. 50 CFR 216.170 - Specified activity and specified geographical region.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... in paragraph (c) of this section. (b) The taking of marine mammals by the Navy is only authorized if... 179° degrees W. long. (c) The taking of marine mammals by the Navy is only authorized if it occurs incidental to the following activities: (1) The use of the following mid-frequency active sonar (MFAS)...

  5. 50 CFR 216.170 - Specified activity and specified geographical region.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... in paragraph (c) of this section. (b) The taking of marine mammals by the Navy is only authorized if... 179° degrees W. long. (c) The taking of marine mammals by the Navy is only authorized if it occurs incidental to the following activities: (1) The use of the following mid-frequency active sonar (MFAS)...

  6. Marine Mammal Active Sonar Test 2004 (MAST 2004)

    NASA Astrophysics Data System (ADS)

    Stein, Peter J.; Vandiver, Amy; Edelson, Geoffrey S.; Frankel, Adam S.; Clark, Christopher W.

    2004-05-01

    The Marine Mammal Active Sonar Test was conducted in January 2004 off the central California coast during the gray whale migration. The purpose of the test was to collect data to significantly advance active sonar detection, classification, and tracking of marine mammals out to ranges of 1 mile. The R/V NEW HORIZON was moored in the migration path. Two different sonar systems operating between 210 and 220 dB were deployed off the vessel, the IMAPS phased array sonar system that operates from 20-30 kHz and the MAST mechanical system that uses rotating parabolic transducers operating from 30 to 40 kHz. Marine mammal observers were deployed on the bluffs overlooking the experiment and aboard the NEW HORIZON. The observers tracked the whales using electronic theodelites, providing ground truth for the sonar systems. They also looked for any severe reactions from the animals, and called for a shutdown if any marine mammals were observed within 100 m of the sonar. Here, we discuss the experiment and the results to date, including any reaction of the whales to the sonar system. We will also touch on the legal battle to conduct the experiment, and lessons learned.

  7. Delphinid behavioral responses to incidental mid-frequency active sonar.

    PubMed

    Henderson, E Elizabeth; Smith, Michael H; Gassmann, Martin; Wiggins, Sean M; Douglas, Annie B; Hildebrand, John A

    2014-10-01

    Opportunistic observations of behavioral responses by delphinids to incidental mid-frequency active (MFA) sonar were recorded in the Southern California Bight from 2004 through 2008 using visual focal follows, static hydrophones, and autonomous recorders. Sound pressure levels were calculated between 2 and 8 kHz. Surface behavioral responses were observed in 26 groups from at least three species of 46 groups out of five species encountered during MFA sonar incidents. Responses included changes in behavioral state or direction of travel, changes in vocalization rates and call intensity, or a lack of vocalizations while MFA sonar occurred. However, 46% of focal groups not exposed to sonar also changed their behavior, and 43% of focal groups exposed to sonar did not change their behavior. Mean peak sound pressure levels when a behavioral response occurred were around 122 dB re: 1 μPa. Acoustic localizations of dolphin groups exhibiting a response gave insight into nighttime movement patterns and provided evidence that impacts of sonar may be mediated by behavioral state. The lack of response in some cases may indicate a tolerance of or habituation to MFA sonar by local populations; however, the responses that occur at lower received levels may point to some sensitization as well.

  8. 50 CFR 218.100 - Specified activity and specified geographical area.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... paragraph (c) of this section. (b) The taking of marine mammals by the Navy may be authorized in a Letter of...°59′24.633″ N. lat, 138°1′29.7228″ E. long. (c) The taking of marine mammals by the Navy may be...: (1) The use of the following mid-frequency active sonar (MFAS) and high frequency active sonar...

  9. 50 CFR 218.100 - Specified activity and specified geographical area.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... paragraph (c) of this section. (b) The taking of marine mammals by the Navy may be authorized in a Letter of...°59′24.633″ N. lat, 138°1′29.7228″ E. long. (c) The taking of marine mammals by the Navy is only... active sonar (MFAS) and high frequency active sonar (HFAS) sources, or similar sources, for Navy...

  10. Method and Apparatus for Improved Active Sonar Using Singular Value Decomposition Filtering

    DTIC Science & Technology

    2007-06-26

    of both projector and receiver of the sonar, type of sonar, range resolution of the sonar, number of eigenrays striking the surface and bottom of the...sonar environment, number of eigenrays striking the target, ray trajectories to the target, and surface and bottom scattering strength as a function...the propagation channel or any other non- homogeneous responses due to channel and/or target interactions. [0052] The system for improved active sonar

  11. Active sonar, beaked whales and European regional policy.

    PubMed

    Dolman, Sarah J; Evans, Peter G H; Notarbartolo-di-Sciara, Giuseppe; Frisch, Heidrun

    2011-01-01

    Various reviews, resolutions and guidance from international and regional fora have been produced in recent years that acknowledge the significance of marine noise and its potential impacts on cetaceans. Within Europe, ACCOBAMS and ASCOBANS have shown increasing attention to the issue. The literature highlights concerns surrounding the negative impacts of active sonar on beaked whales in particular, where concerns primarily relate to the use of mid-frequency active sonar (1-10kHz), as used particularly in military exercises. The authors review the efforts that European regional policies have undertaken to acknowledge and manage possible negative impacts of active sonar and how these might assist the transition from scientific research to policy implementation, including effective management and mitigation measures at a national level.

  12. Trading detection for resolution in active sonar receivers.

    PubMed

    Sharma, Nabin S; Buck, John R; Simmons, James A

    2011-09-01

    This paper proposes an active sonar receivers that offers a smooth trade-off between detection and resolution. A matched filter is the optimal detector of known signals in white Gaussian noise but may fail to resolve the targets if the time separation of targets is less than the mainlobe width of the autocorrelation function of the transmitted signal. An inverse filter achieves optimal resolution performance for multiple targets in the absence of noise, but amplifies the noise outside the signal bandwidth in a manner that makes it impractical in many realistic scenarios. The proposed active sonar receiver, the variable resolution and detection receiver (VRDR) combines the matched and inverse filter properties to achieve a smooth trade-off between detection and resolution. Simulated receiver operating characteristics demonstrate that for a range of dipole sonar targets, the performance of the VRDR is superior to the matched and inverse filter, as well as another previously proposed bandlimited inverse filter.

  13. Digital sonar system

    DOEpatents

    Young, Kenneth K.; Wilkes, R. Jeffrey

    1995-01-01

    A transponder of an active digital sonar system identifies a multifrequency underwater activating sonar signal received from a remote sonar transmitter. The transponder includes a transducer that receives acoustic waves, including the activating sonar signal, and generates an analog electrical receipt signal. The analog electrical receipt signal is converted to a digital receipt signal and cross-correlated with a digital transmission signal pattern corresponding to the activating sonar signal. A relative peak in the cross-correlation value is indicative of the activating sonar signal having been received by the transponder. In response to identifying the activating sonar signal, the transponder transmits a responding multifrequency sonar signal.

  14. Digital sonar system

    DOEpatents

    Young, K.K.; Wilkes, R.J.

    1995-11-21

    A transponder of an active digital sonar system identifies a multifrequency underwater activating sonar signal received from a remote sonar transmitter. The transponder includes a transducer that receives acoustic waves, including the activating sonar signal, and generates an analog electrical receipt signal. The analog electrical receipt signal is converted to a digital receipt signal and cross-correlated with a digital transmission signal pattern corresponding to the activating sonar signal. A relative peak in the cross-correlation value is indicative of the activating sonar signal having been received by the transponder. In response to identifying the activating sonar signal, the transponder transmits a responding multifrequency sonar signal. 4 figs.

  15. 75 FR 5055 - Taking and Importing Marine Mammals; U.S. Navy's Atlantic Fleet Active Sonar Training (AFAST)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-01

    .... Navy's Atlantic Fleet Active Sonar Training (AFAST) AGENCY: National Marine Fisheries Service (NMFS..., testing, and evaluation (RDT&E) activities to be conducted within the Atlantic Fleet Active Sonar Training... side mine hunting sonar in the AFAST Study area, which reduces use from 4474 hours annually to 0....

  16. Application of musical timbre discrimination features to active sonar classification

    NASA Astrophysics Data System (ADS)

    Young, Victor W.; Hines, Paul C.; Pecknold, Sean

    2005-04-01

    In musical acoustics significant effort has been devoted to uncovering the physical basis of timbre perception. Most investigations into timbre rely on multidimensional scaling (MDS), in which different musical sounds are arranged as points in multidimensional space. The Euclidean distance between points corresponds to the perceptual distance between sounds and the multidimensional axes are linked to measurable properties of the sounds. MDS has identified numerous temporal and spectral features believed to be important to timbre perception. There is reason to believe that some of these features may have wider application in the disparate field of underwater acoustics, since anecdotal evidence suggests active sonar returns from metallic objects sound different than natural clutter returns when auralized by human operators. This is particularly encouraging since attempts to develop robust automatic classifiers capable of target-clutter discrimination over a wide range of operational conditions have met with limited success. Spectral features relevant to target-clutter discrimination are believed to include click-pitch and envelope irregularity; relevant temporal features are believed to include duration, sub-band attack/decay time, and time separation pitch. Preliminary results from an investigation into the role of these timbre features in target-clutter discrimination will be presented. [Work supported by NSERC and GDC.

  17. Active Fish Tracking Sonar (AFTS) for Assessing Fish Behavior

    SciTech Connect

    Hedgepeth, J; Johnson, Gary E. ); Skalski, John R.; Burczynski, J

    2002-11-01

    Active fish tracking sonars (AFTS) were used in 2001 to study fish movement in response to intake occlusion plates at The Dalles Dam on the Columbia River. AFTS provides three-dimensional fish tracks by aligning the axis of a split-beam transducer with a fish target. High-speed stepper motors move the transducer so that a tracked target remains on-axis. Occlusion plates with lateral extensions covered the top half of the turbine intakes to produce a fish friendly near-dam environment. Two AFTS were positioned at the center of Main Unit 1, one each for monitoring installed and removed plate conditions. A regression analysis showed that occlusion plates had pronounced effects on fish movement along the dam. The plates appeared to inhibit movement toward the spillway, movement toward the dam (especially in front of the turbine intake), and movement downward toward the turbines. Fish fate (as opposed to movement directions from regression slopes) into particular areas was determined using Markov-chain analysis. The sluiceway (a safer passage route above the turbine intake) zone of influence was larger with the occlusion plates installed, contrary to the regression results. In addition, the probability of passage out the near turbine and bottom sides of the sample volume was about 50% lower with occlusion plates installed.

  18. First direct measurements of behavioural responses by Cuvier's beaked whales to mid-frequency active sonar.

    PubMed

    DeRuiter, Stacy L; Southall, Brandon L; Calambokidis, John; Zimmer, Walter M X; Sadykova, Dinara; Falcone, Erin A; Friedlaender, Ari S; Joseph, John E; Moretti, David; Schorr, Gregory S; Thomas, Len; Tyack, Peter L

    2013-08-23

    Most marine mammal- strandings coincident with naval sonar exercises have involved Cuvier's beaked whales (Ziphius cavirostris). We recorded animal movement and acoustic data on two tagged Ziphius and obtained the first direct measurements of behavioural responses of this species to mid-frequency active (MFA) sonar signals. Each recording included a 30-min playback (one 1.6-s simulated MFA sonar signal repeated every 25 s); one whale was also incidentally exposed to MFA sonar from distant naval exercises. Whales responded strongly to playbacks at low received levels (RLs; 89-127 dB re 1 µPa): after ceasing normal fluking and echolocation, they swam rapidly, silently away, extending both dive duration and subsequent non-foraging interval. Distant sonar exercises (78-106 dB re 1 µPa) did not elicit such responses, suggesting that context may moderate reactions. The observed responses to playback occurred at RLs well below current regulatory thresholds; equivalent responses to operational sonars could elevate stranding risk and reduce foraging efficiency.

  19. Examining the robustness of automated aural classification of active sonar echoes.

    PubMed

    Murphy, Stefan M; Hines, Paul C

    2014-02-01

    Active sonar systems are used to detect underwater man-made objects of interest (targets) that are too quiet to be reliably detected with passive sonar. Performance of active sonar can be degraded by false alarms caused by echoes returned from geological seabed structures (clutter) in shallow regions. To reduce false alarms, a method of distinguishing target echoes from clutter echoes is required. Research has demonstrated that perceptual-based signal features similar to those employed in the human auditory system can be used to automatically discriminate between target and clutter echoes, thereby reducing the number of false alarms and improving sonar performance. An active sonar experiment on the Malta Plateau in the Mediterranean Sea was conducted during the Clutter07 sea trial and repeated during the Clutter09 sea trial. The dataset consists of more than 95,000 pulse-compressed echoes returned from two targets and many geological clutter objects. These echoes were processed using an automatic classifier that quantifies the timbre of each echo using a number of perceptual signal features. Using echoes from 2007, the aural classifier was trained to establish a boundary between targets and clutter in the feature space. Temporal robustness was then investigated by testing the classifier on echoes from the 2009 experiment.

  20. Assessing Beaked Whale Reproduction and Stress Response Relative to Sonar Activity at the Atlantic Undersea Test and Evaluation Center

    DTIC Science & Technology

    2014-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Assessing Beaked Whale Reproduction and Stress Response...both groups of animals to investigate whether there is a relationship between sonar activity, stress measures, and reproductive rates, to assess... Reproduction and Stress Response Relative to Sonar Activity at the Atlantic Undersea Test and Evaluation Center (AUTEC) 5a. CONTRACT NUMBER 5b. GRANT

  1. 77 FR 52317 - Record of Decision for Surveillance Towed Array Sensor System Low Frequency Active Sonar

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF DEFENSE Department of the Navy Record of Decision for Surveillance Towed Array Sensor System Low Frequency Active... Array Sensor System Low Frequency Active (SURTASS LFA) sonar systems with certain...

  2. Continuous Active Sonar for Undersea Vehicles Final Report: Input of Factor Graphs into the Detection, Classification, and Localization Chain and Continuous Active SONAR in Undersea Vehicles

    DTIC Science & Technology

    2015-12-31

    simply adding the two branches. Equation 50 gives the final step before substituting the previously found covanances. (50) where G ~ (v3 + crvz( c [) H ... H can be compared to c since they both are matrices relating the measurement to the state. The variable R in the Kalman filter is the covariance...Wakayama, C . (2013). Multistatic Tracking for Continuous Active Sonar using Doppler-Bearing Measurements. 16th International Conference on Information

  3. Patterns of Occurrence and Marine Mammal Acoustic Behavior in Relation to Navy Sonar Activity Off Jacksonville, Florida.

    PubMed

    Oswald, Julie N; Norris, Thomas F; Yack, Tina M; Ferguson, Elizabeth L; Kumar, Anurag; Nissen, Jene; Bell, Joel

    2016-01-01

    Passive acoustic data collected from marine autonomous recording units deployed off Jacksonville, FL (from 13 September to 8 October 2009 and 3 December 2009 to 8 January 2010), were analyzed for detection of cetaceans and Navy sonar. Cetaceans detected included Balaenoptera acutorostrata, Eubalaena glacialis, B. borealis, Physeter macrocephalus, blackfish, and delphinids. E. glacialis were detected at shallow and, somewhat unexpectedly, deep sites. P. macrocephalus were characterized by a strong diel pattern. B. acutorostrata showed the strongest relationship between sonar activity and vocal behavior. These results provide a preliminary assessment of cetacean occurrence off Jacksonville and new insights on vocal responses to sonar.

  4. A Risk Function for Behavioral Disruption of Blainville’s Beaked Whales (Mesoplodon densirostris) from Mid-Frequency Active Sonar

    PubMed Central

    Moretti, David; Thomas, Len; Marques, Tiago; Harwood, John; Dilley, Ashley; Neales, Bert; Shaffer, Jessica; McCarthy, Elena; New, Leslie; Jarvis, Susan; Morrissey, Ronald

    2014-01-01

    There is increasing concern about the potential effects of noise pollution on marine life in the world’s oceans. For marine mammals, anthropogenic sounds may cause behavioral disruption, and this can be quantified using a risk function that relates sound exposure to a measured behavioral response. Beaked whales are a taxon of deep diving whales that may be particularly susceptible to naval sonar as the species has been associated with sonar-related mass stranding events. Here we derive the first empirical risk function for Blainville’s beaked whales (Mesoplodon densirostris) by combining in situ data from passive acoustic monitoring of animal vocalizations and navy sonar operations with precise ship tracks and sound field modeling. The hydrophone array at the Atlantic Undersea Test and Evaluation Center, Bahamas, was used to locate vocalizing groups of Blainville’s beaked whales and identify sonar transmissions before, during, and after Mid-Frequency Active (MFA) sonar operations. Sonar transmission times and source levels were combined with ship tracks using a sound propagation model to estimate the received level (RL) at each hydrophone. A generalized additive model was fitted to data to model the presence or absence of the start of foraging dives in 30-minute periods as a function of the corresponding sonar RL at the hydrophone closest to the center of each group. This model was then used to construct a risk function that can be used to estimate the probability of a behavioral change (cessation of foraging) the individual members of a Blainville’s beaked whale population might experience as a function of sonar RL. The function predicts a 0.5 probability of disturbance at a RL of 150dBrms re µPa (CI: 144 to 155) This is 15dB lower than the level used historically by the US Navy in their risk assessments but 10 dB higher than the current 140 dB step-function. PMID:24465477

  5. A risk function for behavioral disruption of Blainville's beaked whales (Mesoplodon densirostris) from mid-frequency active sonar.

    PubMed

    Moretti, David; Thomas, Len; Marques, Tiago; Harwood, John; Dilley, Ashley; Neales, Bert; Shaffer, Jessica; McCarthy, Elena; New, Leslie; Jarvis, Susan; Morrissey, Ronald

    2014-01-01

    There is increasing concern about the potential effects of noise pollution on marine life in the world's oceans. For marine mammals, anthropogenic sounds may cause behavioral disruption, and this can be quantified using a risk function that relates sound exposure to a measured behavioral response. Beaked whales are a taxon of deep diving whales that may be particularly susceptible to naval sonar as the species has been associated with sonar-related mass stranding events. Here we derive the first empirical risk function for Blainville's beaked whales (Mesoplodon densirostris) by combining in situ data from passive acoustic monitoring of animal vocalizations and navy sonar operations with precise ship tracks and sound field modeling. The hydrophone array at the Atlantic Undersea Test and Evaluation Center, Bahamas, was used to locate vocalizing groups of Blainville's beaked whales and identify sonar transmissions before, during, and after Mid-Frequency Active (MFA) sonar operations. Sonar transmission times and source levels were combined with ship tracks using a sound propagation model to estimate the received level (RL) at each hydrophone. A generalized additive model was fitted to data to model the presence or absence of the start of foraging dives in 30-minute periods as a function of the corresponding sonar RL at the hydrophone closest to the center of each group. This model was then used to construct a risk function that can be used to estimate the probability of a behavioral change (cessation of foraging) the individual members of a Blainville's beaked whale population might experience as a function of sonar RL. The function predicts a 0.5 probability of disturbance at a RL of 150 dBrms re µPa (CI: 144 to 155) This is 15dB lower than the level used historically by the US Navy in their risk assessments but 10 dB higher than the current 140 dB step-function.

  6. The application of m-sequences to bi-static active sonar

    NASA Astrophysics Data System (ADS)

    Deferrari, Harry A.

    2003-10-01

    The m-sequences are ideal pulse compression signals that combine the energy of CW with the resolution of a pulse. Successful applications include numerous acoustic propagation experiments and the Global Positioning System. Yet, early attempts (circa 1960) to apply m-sequences to mono-static active sonar were unsuccessful. Through the years, Birdsall, Metzger and others have developed a body of theory, numerical methods and at-sea demonstrations that establish the feasibility of a novel bi-static approach-one that holds promise in high reverberation shallow water environs. An analysis is presented here. The approach includes (1) continuous transmission of long m-sequences (2) synchronous sampling to form a CON (Complete Ortho-Normal) data set; (3) direct blast removal by HCCO (Hyperspace Cancellation by Coordinate Zeroing); and (4) a full range waveform Doppler search. Ultra-fast Hadamard Transforms speed up the direct waveform pulse m-sequence pulse compression and the inverse pulse waveform transform and thereby allow timely execution of the intensive computational burden. The result is a demonstrable approach that produces a gain of 30 dB over a simple pulse and 10 dB over other sonar signals. In the end, the approach requires continuous transmission and reception as opposed to ping and listen an awkward concept at first.

  7. Sperm whales reduce foraging effort during exposure to 1-2 kHz sonar and killer whale sounds.

    PubMed

    Isojunno, Saana; Cure, Charlotte; Kvadsheim, Petter Helgevold; Lam, Frans-Peter Alexander; Tyack, Peter Lloyd; Wensveen, Paul Jacobus; Miller, Patrick James O'Malley

    2016-01-01

    The time and energetic costs of behavioral responses to incidental and experimental sonar exposures, as well as control stimuli, were quantified using hidden state analysis of time series of acoustic and movement data recorded by tags (DTAG) attached to 12 sperm whales (Physeter macrocephalus) using suction cups. Behavioral state transition modeling showed that tagged whales switched to a non-foraging, non-resting state during both experimental transmissions of low-frequency active sonar from an approaching vessel (LFAS; 1-2 kHz, source level 214 dB re 1 µPa m, four tag records) and playbacks of potential predator (killer whale, Orcinus orca) sounds broadcast at naturally occurring sound levels as a positive control from a drifting boat (five tag records). Time spent in foraging states and the probability of prey capture attempts were reduced during these two types of exposures with little change in overall locomotion activity, suggesting an effect on energy intake with no immediate compensation. Whales switched to the active non-foraging state over received sound pressure levels of 131-165 dB re 1 µPa during LFAS exposure. In contrast, no changes in foraging behavior were detected in response to experimental negative controls (no-sonar ship approach or noise control playback) or to experimental medium-frequency active sonar exposures (MFAS; 6-7 kHz, source level 199 re 1 µPa m, received sound pressure level [SPL] = 73-158 dB re 1 µPa). Similarly, there was no reduction in foraging effort for three whales exposed to incidental, unidentified 4.7-5.1 kHz sonar signals received at lower levels (SPL = 89-133 dB re 1 µPa). These results demonstrate that similar to predation risk, exposure to sonar can affect functional behaviors, and indicate that increased perception of risk with higher source level or lower frequency may modulate how sperm whales respond to anthropogenic sound.

  8. 75 FR 81284 - Nationwide Use of High Frequency and Ultra High Frequency Active SONAR Technology; Draft...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-27

    ... SONAR technologies that operate at frequencies of 50 kiloHertz (kHz) and greater from mobile platforms... proposes to use HF and UHF SONAR technology from mobile platforms nationwide. Mobile platforms include...-specific, non-mobile operating scenarios or newly developed technologies fall outside of the scope of...

  9. Potential Population Consequences of Active Sonar Disturbance in Atlantic Herring: Estimating the Maximum Risk.

    PubMed

    Sivle, Lise Doksæter; Kvadsheim, Petter Helgevold; Ainslie, Michael

    2016-01-01

    Effects of noise on fish populations may be predicted by the population consequence of acoustic disturbance (PCAD) model. We have predicted the potential risk of population disturbance when the highest sound exposure level (SEL) at which adult herring do not respond to naval sonar (SEL(0)) is exceeded. When the population density is low (feeding), the risk is low even at high sonar source levels and long-duration exercises (>24 h). With densely packed populations (overwintering), a sonar exercise might expose the entire population to levels >SEL(0) within a 24-h exercise period. However, the disturbance will be short and the response threshold used here is highly conservative. It is therefore unlikely that naval sonar will significantly impact the herring population.

  10. 78 FR 70567 - Nationwide Use of High Frequency and Ultra High Frequency Active SONAR Technology; Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ... Frequency (UHF) Sound Navigation and Ranging (SONAR) Technology and Finding of No Significant Impact (FONSI..., day or night regardless of visibility and in air and water temperatures and thermoclines normal...

  11. The effect of active sonar for the protection of moored and anchored warships on the human hearing.

    PubMed

    Salami, Angelo; Dellepiane, Massimo; Barbierato, Mauro; Freda, Pierluigi; Crippa, Barbara; Guastini, Luca; Mora, Renzo

    2010-02-01

    This study wants to show the effects of active middle frequency sonar on a selected group of Italian Navy divers. Ten male divers with normal hearing were exposed to active sonar of the Italian Navy for more than 100 exposures, each of at least 1-h duration, in the course of 6 months. Before, at the end, and six months after the end of noise exposure, we performed pure-tone audiometry, Carhart test, Peyser test, thresholds of discomfort test (TDT), tympanometry, transient evoked otoacoustic emissions (TEOAE), distortion product otoacoustic emissions (DPOAE), and auditory brainstem response (ABR). At the end of the noise exposure, the audiological tests showed a worsening of the mean air and bone audiometric thresholds at the 2,000 (1/10), 4,000 (7/10), and 8,000 Hz (6/10); a fail status of the TEOAE and DPOAE, which were previously present, in all the divers; temporary threshold shift, at the Peyser test, in 9/10 divers; discomfort for pulse tone presented at the TDT test, in all the divers; no post exposure significant differences at the Carhart and ABR tests, in any of the divers. Six months after the end of noise exposure, all the divers presented a complete recovery of their audio-vestibular functions. Our results show the temporary negative effects of repeated and lasting exposure to active sonar (Hull MF) on the divers; the last control demonstrate the absence of permanent noise-induced hearing loss in divers exposed to active sonar.

  12. Assessing Beaked Whale Reproduction and Stress Response Relative to Sonar Activity at the Atlantic Undersea Test and Evaluation Center (AUTEC)

    DTIC Science & Technology

    2011-09-30

    England. (2001) Joint interim report Bahamas marine mammal stranding event of 15 – 16 March 2000. National Oceanographic and Atmospheric Administration...Relative to Sonar Activity at the Atlantic Undersea Test and Evaluation Center (AUTEC) Diane Elaine Claridge Bahamas Marine Mammal Research...ADDRESS(ES) Bahamas Marine Mammal Research Organisation,P.O. Box AB-20714,Marsh Harbour,Abaco, Bahamas, 8. PERFORMING ORGANIZATION REPORT NUMBER 9

  13. Target-depth estimation in active sonar: Cramer-Rao bounds for a bilinear sound-speed profile.

    PubMed

    Mours, Alexis; Ioana, Cornel; Mars, Jérôme I; Josso, Nicolas F; Doisy, Yves

    2016-09-01

    This paper develops a localization method to estimate the depth of a target in the context of active sonar, at long ranges. The target depth is tactical information for both strategy and classification purposes. The Cramer-Rao lower bounds for the target position as range and depth are derived for a bilinear profile. The influence of sonar parameters on the standard deviations of the target range and depth are studied. A localization method based on ray back-propagation with a probabilistic approach is then investigated. Monte-Carlo simulations applied to a summer Mediterranean sound-speed profile are performed to evaluate the efficiency of the estimator. This method is finally validated on data in an experimental tank.

  14. Effects of surveillance towed array sensor system (SURTASS) low frequency active sonar on fish

    NASA Astrophysics Data System (ADS)

    Popper, Arthur N.; Halvorsen, Michele B.; Miller, Diane; Smith, Michael E.; Song, Jiakun; Wysocki, Lidia E.; Hastings, Mardi C.; Kane, Andrew S.; Stein, Peter

    2005-04-01

    We investigated the effects of exposure to Low Frequency Active (LFA) sonar on rainbow trout (a hearing non-specialist related to several endangered salmonids) and channel catfish (a hearing specialist), using an element of the standard SURTASS LFA source array. We measured hearing sensitivity using auditory brainstem response, effects on inner ear structure using scanning electron microscopy, effects on non-auditory tissues using general pathology and histopathology, and behavioral effects with video monitoring. Exposure to 193 dB re 1 microPa (rms received level) in the LFA frequency band for 324 seconds resulted in a TTS of 20 dB at 400 Hz in rainbow trout, with less TTS at 100 and 200 Hz. TTS in catfish ranged from 6 to 12 dB at frequencies from 200 to 1000 Hz. Both species recovered from hearing loss in several days. Inner ears sensory tissues appeared unaffected by acoustic exposure. Gross pathology indicated no damage to non-auditory tissues, including the swim bladder. Both species showed consistent startle responses at sound onsets and changed their position relative to the sound source during exposures. There was no fish death attributable to sound exposure even up to four days post-exposure. [Work supported by Chief of Naval Operations.

  15. Sidescan sonar imagery of widespread fossil and active cold seeps along the central Chilean continental margin

    NASA Astrophysics Data System (ADS)

    Klaucke, Ingo; Weinrebe, Wilhelm; Linke, Peter; Kläschen, Dirk; Bialas, Jörg

    2012-12-01

    The central Chilean subduction zone between 35°S and 37°S was investigated in order to identify, document and possibly understand fluid flow and fluid venting within the forearc region. Several areas were mapped using multibeam bathymetry and backscatter, high-resolution sidescan sonar, chirp subbottom profiling and reflection seismic data. On a subsequent cruise ground-truthing observations were made using a video sled. In general, this dataset shows surprisingly little evidence of fluid venting along the mid-slope region, in contrast to other subduction zones such as Central America and New Zealand. There were abundant indications of active and predominantly fossil fluid venting along the upper slope between 36.5°S and 36.8°S at the seaward margin of an intraslope basin. Here, backscatter anomalies suggest widespread authigenic carbonate deposits, likely the result of methane-rich fluid expulsion. There is unpublished evidence that these fluids are of biogenic origin and generated within the slope sediments, similar to other accretionary margins but in contrast to the erosional margin off Central America, where fluids have geochemical signals indicating an origin from the subducting plate.

  16. Classification of elastic objects by active sonar in the vicinity of shallow sea boundaries

    NASA Astrophysics Data System (ADS)

    Gaunaurd, Guillermo C.; Werby, Michael F.

    1992-09-01

    Active sonar classification of submerged elastic structures becomes increasingly difficult when the structure is close to the bottom or surface of the sea. The backscattering cross-section (BSCS) of any target, which is relatively simpler to determine in deep waters, away from boundaries, becomes substantially distorted as the structure approaches either one of these environmental boundaries. Near these interfaces the classification methodology based on echo resonances that we have used in the past (viz., Appl. Mechanics Reviews 43, 171-208, (1990)) can no longer be used. By means of the examples of a spherical shell and an elastic solid sphere insonified by plane waves, we study the above mentioned degradation in BSCS in order to assess how distant the structure should be from these boundaries before the resonance features become discernible again in the echoes, and object recognition is again possible. Our approach is based on the method of images for the construction of the appropriate Green's functions, combined with a very involved two-body scattering formulation that determines the combined T-Matrix of two insonified objects, when the T-Matrix of each individual object is known. The method is extended to the time domain. We present form-functions in the frequency domain, as well as late-time responses in the time domain for both sphere and shell as they approach the mentioned boundaries. Boundary effects seem to be confined to a 'skin layer' bounded by R

  17. Digitally controlled sonars

    NASA Technical Reports Server (NTRS)

    Hansen, G. R.

    1983-01-01

    Sonars are usually designed and constructed as stand alone instruments. That is, all elements or subsystems of the sonar are provided: power conditioning, displays, intercommunications, control, receiver, transmitter, and transducer. The sonars which are a part of the Advanced Ocean Test Development Platform (AOTDP) represent a departure from this manner of implementation and are configured more like an instrumentation system. Only the transducer, transmitter, and receiver which are unique to a particular sonar function; Up, Down, Side Scan, exist as separable subsystems. The remaining functions are reserved to the AOTDP and serve all sonars and other instrumentation in a shared manner. The organization and functions of the common AOTDP elements were described and then the interface with the sonars discussed. The techniques for software control of the sonar parameters were explained followed by the details of the realization of the sonar functions and some discussion of the performance of the side scan sonars.

  18. An Improved Azimuth Angle Estimation Method with a Single Acoustic Vector Sensor Based on an Active Sonar Detection System.

    PubMed

    Zhao, Anbang; Ma, Lin; Ma, Xuefei; Hui, Juan

    2017-02-20

    In this paper, an improved azimuth angle estimation method with a single acoustic vector sensor (AVS) is proposed based on matched filtering theory. The proposed method is mainly applied in an active sonar detection system. According to the conventional passive method based on complex acoustic intensity measurement, the mathematical and physical model of this proposed method is described in detail. The computer simulation and lake experiments results indicate that this method can realize the azimuth angle estimation with high precision by using only a single AVS. Compared with the conventional method, the proposed method achieves better estimation performance. Moreover, the proposed method does not require complex operations in frequencydomain and achieves computational complexity reduction.

  19. An Improved Azimuth Angle Estimation Method with a Single Acoustic Vector Sensor Based on an Active Sonar Detection System

    PubMed Central

    Zhao, Anbang; Ma, Lin; Ma, Xuefei; Hui, Juan

    2017-01-01

    In this paper, an improved azimuth angle estimation method with a single acoustic vector sensor (AVS) is proposed based on matched filtering theory. The proposed method is mainly applied in an active sonar detection system. According to the conventional passive method based on complex acoustic intensity measurement, the mathematical and physical model of this proposed method is described in detail. The computer simulation and lake experiments results indicate that this method can realize the azimuth angle estimation with high precision by using only a single AVS. Compared with the conventional method, the proposed method achieves better estimation performance. Moreover, the proposed method does not require complex operations in frequency-domain and achieves computational complexity reduction. PMID:28230763

  20. Imaging Active and Relict Seafloor Methane Seep Sites: a Comparison of Seafloor 3D Seismic Reflectivity and Multibeam Sonar Backscatter Intensity at Omakere Ridge, Hikurangi Margin, New Zealand

    NASA Astrophysics Data System (ADS)

    Golding, T. V.; Pecher, I. A.; Crutchley, G. J.; Klaeschen, D.; Papenberg, C. A.; Bialas, J.; Greinert, J.; Townend, J.; SO214 Shipboard Scientific Party

    2011-12-01

    Omakere Ridge is an anticlinal thrust ridge in water depths of 1100-1700 m on the Hikurangi Margin, east of the North Island of New Zealand, and an area of active seafloor methane seepage associated with an extensive gas hydrate province. Methane seep sites on the Hikurangi Margin are characterised by localised build-ups of hard authigenic carbonate and chemosynthetic seep fauna that exist on a seafloor otherwise characterised by soft, muddy sediments. Previous studies have shown that these seep sites appear as areas of high backscatter in sonar images, but backscatter data alone do not provide detailed information on the present level of activity of a seep site, or the thickness of the carbonate build-up. Here we present a comparison of seafloor seismic reflectivity and multibeam sonar backscatter intensity data collected from active and relict methane seep sites on Omakere Ridge. High-resolution P-Cable 3D seismic reflection data and 12 kHz EM120 multibeam sonar data were collected in March 2011 during the RV Sonne cruise SO214. Seafloor seismic amplitude maps have been derived from the shipboard post-stack migrated data cube. A pronounced acquisition artifact is manifest in the seafloor horizon slice as high and low amplitude stripes that alternate periodically in the crossline direction. We have removed this artifact from the seafloor horizon slice using Kx-Ky filtering, followed by direct sampling and deterministic removal of the very-low-frequency components in the spatial domain. The seismic amplitude map has then been transformed into a calibrated seafloor reflection coefficient map. Sonar backscatter mosaics have been created after correcting for instrument response, angular variation in backscatter and bathymetry. Several backscatter mosaics were incorporated into a stacked mosaic over the study area to attenuate random noise. The high sonar backscatter response at the seep sites is generally accompanied by high seismic reflectivity. However, the

  1. Active part of Charlie--Gibbs fracture zone: A study using sonar and other geophysical techniques

    SciTech Connect

    Searle, R.

    1981-01-10

    A short survey with Gloria side-scan sonar and other geophysical instruments has revealed new information about Charlie--Gibbs fracture zone between 29/sup 0/ and 36 /sup 0/W. The traces of two transform faults have been clearly delineated. They fit small circles about the pole of rotation with an rms error of only about 1 km, but they do not always follow the deepest parts of the transform valleys. The transforms are joined by a short spreading center at 31 /sup 0/45 'W. The median transverse ridge appears to have been produced by normal seafloor spreading at this center and bears identifiable Vine-Matthews magnetic anomalies. A transverse ridge along the eastern inactive part of the northern transform may be an intrusive feature. Considerable thickness of sediment appear to have been deposited in the northern transform valley from Norwegian Sea overflow water passing through the fracture zone, but transverse ridges have prevented the sediment reaching the southern valley.

  2. Navigation Hazard Survey Sonar.

    DTIC Science & Technology

    1982-04-01

    NSTL Station, Miss., NORDA Technical Note 17. Flemming, B.W. (1976). Side Scan Sonar: A Practical Guide. Int. Hydrog . Rev., 53(1), p. 65-92. Harris...Corporation, Harris Division, Westwoo, Mass., 02090, manufacturer brochure. Leenhardt, 0. (1975). Side canning Sonar -- A Theoretical Study. Int. Hydrog . Rev

  3. A Robust and Fast Method for Sidescan Sonar Image Segmentation Using Nonlocal Despeckling and Active Contour Model.

    PubMed

    Huo, Guanying; Yang, Simon X; Li, Qingwu; Zhou, Yan

    2017-04-01

    Sidescan sonar image segmentation is a very important issue in underwater object detection and recognition. In this paper, a robust and fast method for sidescan sonar image segmentation is proposed, which deals with both speckle noise and intensity inhomogeneity that may cause considerable difficulties in image segmentation. The proposed method integrates the nonlocal means-based speckle filtering (NLMSF), coarse segmentation using k -means clustering, and fine segmentation using an improved region-scalable fitting (RSF) model. The NLMSF is used before the segmentation to effectively remove speckle noise while preserving meaningful details such as edges and fine features, which can make the segmentation easier and more accurate. After despeckling, a coarse segmentation is obtained by using k -means clustering, which can reduce the number of iterations. In the fine segmentation, to better deal with possible intensity inhomogeneity, an edge-driven constraint is combined with the RSF model, which can not only accelerate the convergence speed but also avoid trapping into local minima. The proposed method has been successfully applied to both noisy and inhomogeneous sonar images. Experimental and comparative results on real and synthetic sonar images demonstrate that the proposed method is robust against noise and intensity inhomogeneity, and is also fast and accurate.

  4. Application of the T-Matrix Method to the Numerical Modeling of a Linear Active Sonar Array

    DTIC Science & Technology

    2013-06-01

    5 2.1 COMSOL Finite Element Analysis . . . . . . . . . . . . . . . . . . . 5 2.2 Piezoelectric Spherical Thin-Shell Transducer...maximize the directionality and steer optimum acoustic beams . Figure 1.1 shows two examples of volumetric sonar array applications. (a) (b) Figure 1.1...single-transducer, from such as a finite -element model (FEM). This thesis focuses on building a three- dimensional (3D) FEM of a volumetric

  5. Measurement of fish movements at depths to 6000 m using a deep-ocean lander incorporating a short base-line sonar utilizing miniature code-activated transponder technology

    NASA Astrophysics Data System (ADS)

    Bagley, P. M.; Bradley, S.; Priede, I. G.; Gray, P.

    1999-12-01

    Most research on animal behaviour in the deep ocean (to depths of 6000 m) is restricted to the capture of dead specimens or viewing activity over small areas of the sea floor by means of cameras or submersibles. This paper describes the use of a miniature acoustic code-activated transponder (CAT) tag and short base-line sonar to track the movements of deep-sea fish in two dimensions over an area 1 km in diameter centred on a lander platform. The CAT tags and sonar are transported to the deep-sea floor by means of a subsea mooring which is ballasted so that it lands and remains on the sea floor for the duration of the tracking experiment (the lander). A description of the CAT, lander and short base-line sonar is given. Results are presented to illustrate the operation of the system.

  6. Behavioral responses by grey seals (Halichoerus grypus) to high frequency sonar.

    PubMed

    Hastie, Gordon D; Donovan, Carl; Götz, Thomas; Janik, Vincent M

    2014-02-15

    The use of high frequency sonar is now commonplace in the marine environment. Most marine mammals rely on sound to navigate, and for detecting prey, and there is the potential that the acoustic signals of sonar could cause behavioral responses. To investigate this, we carried out behavioral response tests with grey seals to two sonar systems (200 and 375 kHz systems). Results showed that both systems had significant effects on the seals behavior; when the 200 kHz sonar was active, seals spent significantly more time hauled out and, although seals remained swimming during operation of the 375 kHz sonar, they were distributed further from the sonar. The results show that although peak sonar frequencies may be above marine mammal hearing ranges, high levels of sound can be produced within their hearing ranges that elicit behavioral responses; this has clear implications for the widespread use of sonar in the marine environment.

  7. Gain control in the sonar of odontocetes.

    PubMed

    Ya Supin, Alexander; Nachtigall, Paul E

    2013-06-01

    The sonar of odontocetes processes echo-signals within a wide range of echo levels. The level of echoes varies widely by tens of decibels depending on the level of the emitted sonar pulse, the target strength, the distance to the target, and the sound absorption by the water media. The auditory system of odontocetes must be capable of effective perception, analysis, and discrimination of echo-signals within all this variability. The sonar of odontocetes has several mechanisms to compensate for the echo-level variation (gain control). To date, several mechanisms of the biosonar gain control have been revealed in odontocetes: (1) adjustment of emitted sonar pulse levels (the longer the distance to the target, the higher the level of the emitted pulse), (2) short-term variation of hearing sensitivity based on forward masking of the echo by the preceding self-heard emitted pulse and subsequent release from the masking, and (3) active long-term control of hearing sensitivity. Recent investigations with the use of the auditory evoked-potential technique have demonstrated that these mechanisms effectively minimize the variation of the response to the echo when either the emitted sonar pulse level, or the target distance, or both vary within a wide range. A short review of these data is presented herein.

  8. Multiple Frequency Parametric Sonar

    DTIC Science & Technology

    2015-09-28

    300003 1 MULTIPLE FREQUENCY PARAMETRIC SONAR STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured and...beams. However, the multiple nonlinear interactions are not taken advantage of in order to generate additional efficiencies, bandwidth, and SNR...array. [0050] It will be understood that many additional changes in details, materials , steps, and arrangements of parts which have been described

  9. Miniature sonar fish tag

    NASA Technical Reports Server (NTRS)

    Lovelady, R. W.; Ferguson, R. L.

    1975-01-01

    Self-powered sonar device may be implanted in body of fish. It transmits signal that can be detected with portable tracking gear or by automatic detection-and-tracking system. Operating life of over 4000 hours may be expected. Device itself may be used almost indefinitely.

  10. Obstacle avoidance sonar for submarines

    NASA Astrophysics Data System (ADS)

    Dugas, Albert C.; Webman, Kenneth M.

    2002-05-01

    The Advanced Mine Detection Sonar (AMDS) system was designed to operate in poor environments with high biological and/or shallow-water boundary conditions. It provides increased capability for active detection of volume, close-tethered, and bottom mines, as well as submarine and surface target active/passive detection for ASW and collision avoidance. It also provides bottom topography mapping capability for precise submarine navigation in uncharted littoral waters. It accomplishes this by using advanced processing techniques with extremely narrow beamwidths. The receive array consists of 36 modules arranged in a 15-ft-diameter semicircle at the bottom of the submarine sonar dome to form a chin-mounted array. Each module consists of 40 piezoelectric rubber elements. The modules provide the necessary signal conditioning to the element data prior to signal transmission (uplink) through the hull. The elements are amplified, filtered, converted to digital signals by an A/D converter, and multiplexed prior to uplink to the inboard receiver. Each module also has a downlink over which it receives synchronization and mode/gain control. Uplink and downlink transmission is done using fiberoptic telemetry. AMDS was installed on the USS Asheville. The high-frequency chin array for Virginia class submarines is based on the Asheville design.

  11. Principles of Sonar Installation

    DTIC Science & Technology

    1982-01-26

    4) sonar release mechanisms, (5) fish finders, (6) counter«; and trackers, and (7) telemetry systems that use acoustic beams in- stead of wire ...multiplexing (CDM). When multiplexing is not employed, a pair of twisted wires is used for each hydrophone but the method creates a very bulky cable ...the necessity of auxiliary beamforming electronics . A typical beam pattern is shown in figure 1.48; it was obtained Figure 1.47. Focusing using a

  12. Observing Ocean Ecosystems with Sonar

    SciTech Connect

    Matzner, Shari; Maxwell, Adam R.; Ham, Kenneth D.; Hytnen, Ross D.; Horne, John

    2016-12-01

    We present a real-time processing system for sonar to detect and track animals, and to extract water column biomass statistics in order to facilitate continuous monitoring of an underwater environment. The Nekton Interaction Monitoring System (NIMS) is built to connect to an instrumentation network, where it consumes a real-time stream of sonar data and archives tracking and biomass data.

  13. Security sonar for water intakes

    SciTech Connect

    Rothenbuhler, D.E.

    1987-07-01

    The security of the water approaches to nuclear facilities has been largely neglected because of the lack of solutions to the intrusion problem. This paper reviews underwater scanning sonar in general, highlights a number of problems encountered in a threat detection system using sonar and suggests some procedures that can help make such a system workable. Information is drawn from recent experience with several security projects in the governmental and private sectors, one of which was a nuclear facility.

  14. Bats coordinate sonar and flight behavior as they forage in open and cluttered environments.

    PubMed

    Falk, Benjamin; Jakobsen, Lasse; Surlykke, Annemarie; Moss, Cynthia F

    2014-12-15

    Echolocating bats use active sensing as they emit sounds and listen to the returning echoes to probe their environment for navigation, obstacle avoidance and pursuit of prey. The sensing behavior of bats includes the planning of 3D spatial trajectory paths, which are guided by echo information. In this study, we examined the relationship between active sonar sampling and flight motor output as bats changed environments from open space to an artificial forest in a laboratory flight room. Using high-speed video and audio recordings, we reconstructed and analyzed 3D flight trajectories, sonar beam aim and acoustic sonar emission patterns as the bats captured prey. We found that big brown bats adjusted their sonar call structure, temporal patterning and flight speed in response to environmental change. The sonar beam aim of the bats predicted the flight turn rate in both the open room and the forest. However, the relationship between sonar beam aim and turn rate changed in the forest during the final stage of prey pursuit, during which the bat made shallower turns. We found flight stereotypy developed over multiple days in the forest, but did not find evidence for a reduction in active sonar sampling with experience. The temporal patterning of sonar sound groups was related to path planning around obstacles in the forest. Together, these results contribute to our understanding of how bats coordinate echolocation and flight behavior to represent and navigate their environment.

  15. Bats coordinate sonar and flight behavior as they forage in open and cluttered environments

    PubMed Central

    Falk, Benjamin; Jakobsen, Lasse; Surlykke, Annemarie; Moss, Cynthia F.

    2014-01-01

    Echolocating bats use active sensing as they emit sounds and listen to the returning echoes to probe their environment for navigation, obstacle avoidance and pursuit of prey. The sensing behavior of bats includes the planning of 3D spatial trajectory paths, which are guided by echo information. In this study, we examined the relationship between active sonar sampling and flight motor output as bats changed environments from open space to an artificial forest in a laboratory flight room. Using high-speed video and audio recordings, we reconstructed and analyzed 3D flight trajectories, sonar beam aim and acoustic sonar emission patterns as the bats captured prey. We found that big brown bats adjusted their sonar call structure, temporal patterning and flight speed in response to environmental change. The sonar beam aim of the bats predicted the flight turn rate in both the open room and the forest. However, the relationship between sonar beam aim and turn rate changed in the forest during the final stage of prey pursuit, during which the bat made shallower turns. We found flight stereotypy developed over multiple days in the forest, but did not find evidence for a reduction in active sonar sampling with experience. The temporal patterning of sonar sound groups was related to path planning around obstacles in the forest. Together, these results contribute to our understanding of how bats coordinate echolocation and flight behavior to represent and navigate their environment. PMID:25394632

  16. High-resolution seismic and side scan sonar imaging of active structures and Quaternary channels on the shallow shelf of Otago, southeastern New Zealand

    NASA Astrophysics Data System (ADS)

    Gorman, A. R.; Bruce, C.; Preskett, S. A.; Norris, R.; Choveaux, R.; Flemish, H.; Green, C.

    2011-12-01

    The shallow and narrow continental shelf off the coast of Otago has unique geological characteristics due to the juxtaposition of active coast-parallel contractional faults related to the nearby Pacific-Australian plate boundary and late-Miocene shield volcanism that affects the structural and sedimentological regimes of the region. For example, the offshore extent of the active Akatore Fault, a NE-SW trending reverse fault that runs along the coast SW of Dunedin, is poorly constrained to the northeast where is intersects the Dunedin Volcanic Complex. This fault is possibly associated with several other offshore coast-parallel faults based on shallow controlled-source seismic data. Historical earthquakes, including those of 1974 and 1989, are attributed these faults. The Dunedin Volcanic Complex also has impacted Quaternary erosional and sedimentation patterns on the shelf as a result of topographical features that affect drainage and sediment transport patterns. Single-channel electro-acoustic boomer seismic reflection data and side scan sonar profiles have been collected along a ~35-km-long section of the shallow shelf SW of Dunedin over the last three years. The majority of lines were collected along NW-SE azimuths (perpendicular to the coast), running from just outside the surf zone (<10 m water depth) to a maximum of 28 km offshore (~75 m water depth). Survey lines were ~250 m apart near shore and up to 5 km apart offshore. Boomer subsurface penetration is limited, primarily by the presence of multiple reflections. However, primary reflections were recorded from sub-seafloor depths of up to 100 m. Several significant structures have been imaged within the survey area, principally the Akatore and Green Island Faults. The Akatore Fault is imaged very near shore in the southern portion of the survey, and a minimum post-Miocene displacement of 55 m was calculated. Offset on the Green Island Fault, a high-angle reverse fault, was relatively well constrained to ~200

  17. Sonar equations for planetary exploration.

    PubMed

    Ainslie, Michael A; Leighton, Timothy G

    2016-08-01

    The set of formulations commonly known as "the sonar equations" have for many decades been used to quantify the performance of sonar systems in terms of their ability to detect and localize objects submerged in seawater. The efficacy of the sonar equations, with individual terms evaluated in decibels, is well established in Earth's oceans. The sonar equations have been used in the past for missions to other planets and moons in the solar system, for which they are shown to be less suitable. While it would be preferable to undertake high-fidelity acoustical calculations to support planning, execution, and interpretation of acoustic data from planetary probes, to avoid possible errors for planned missions to such extraterrestrial bodies in future, doing so requires awareness of the pitfalls pointed out in this paper. There is a need to reexamine the assumptions, practices, and calibrations that work well for Earth to ensure that the sonar equations can be accurately applied in combination with the decibel to extraterrestrial scenarios. Examples are given for icy oceans such as exist on Europa and Ganymede, Titan's hydrocarbon lakes, and for the gaseous atmospheres of (for example) Jupiter and Venus.

  18. Stability augmentation and mosaic method of forward-scan sonar images

    NASA Astrophysics Data System (ADS)

    Xie, Shaorong; Luo, Jun; Chen, Jinbo; Xu, Yuanyu

    2012-06-01

    In recent years, forward-scan sonar is widely applied to the underwater inspection, which is not subject to the influence of light and turbidity. For expanding the monitoring scope, the image sonar is generally mounted on the pan-tilt platform of a ROV (Remotely Operated Vehicle) or survey boat. However, there are still some problems such as: 1) The field-of-view is narrow, i.e. the horizontal view angle of DIDSON (Dual-frequency identification sonar) is 29° 2) The dynamic change of a ROV or survey boat by the water disturbances will cause the target to escape from the sonar image easily; 3) The image sonar is fixed on the pan-tilt platform, and its position and posture are unceasingly changed. As a result of these problems, the obtained images may be distorted and not on the same plane. To solve the above problems, stability augmentation of pan-tilt platform based on the principle of bionic eye movements and a mosaic method of sonar images are presented. According to the principle of the vestibule-ocular reflex, an active compensation control system of the mechanical pan-tilt platform is developed. It can compensate the sonar image instability resulting from attitude variation of a ROV or survey boat during operation. Applying multi-sensor fusion technology can rectify the sonar images with different position and posture to be on a single geodetic coordinate frame for image matching. Finally, sonar images can be mosaic. A stable large-scale sonar image can be obtained. The experimental results validate that the presented method is valid.

  19. Marine Mammals and Active Sonar

    DTIC Science & Technology

    2005-10-01

    small effort to look at noise impacts on Beluga whales also serves to build expertise and an understanding of the general complexities. A new...Thomas, and R. A. Kastelein. 1988. Low-frequency underwater hearing sensitivity in belugas , Delphinapterus leucas. Journal of the Acoustical Society of...C. and Farmer, D. M. 2000. Zones of impact around icebreakers affecting beluga whales in the Beaufort Sea. Journal of the Acoustical Society of

  20. A Study to Interpret the Biological Significance of Behavior Associated with 3S Experimental Sonar Exposures

    DTIC Science & Technology

    2015-09-30

    playback of killer whale sounds across the 3S species; and 3.) quantification of the possible impacts of sonar exposure on energy expenditure by linking respiration behavior and underwater activity recorded by Dtags.

  1. Cetacean Social Behavioral Response to Sonar Exposure

    DTIC Science & Technology

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Cetacean social behavioral response to sonar exposure Dr...TERM GOALS The goal of this effort is to investigate cetacean social behavioral response to sonar signals. OBJECTIVES The scientific objectives...of this effort are to determine: 1) social behavioral responses of cetaceans to sonar and to tagging, to investigate the biological relevance and

  2. Sonar Test and Test Instrumentation Support.

    DTIC Science & Technology

    1976-11-10

    6487 < rM SEL ECTE CO, BU 9 1 Approved for public release;distribution unlimited. 611 095 A DNAR IA ST WI EST INSTRUMENTATIONJUPPORT.J ) Quaterly ...INSTRUMENTATION TEST AND EVALUATION 17 A. Introduction 17 B. Operational Testing of the AN/WQM-7 Sonar Test Set 17 C. AN/SQM-( ) Feasibility Study 19 VII. STUDY ...AN/WQM-5 Sonar Test Set Field Support IV. Special Purpose Passive Sonar Systems Support V. Sonar Instrumentation Test and Evaluation VI. Study of

  3. Place recognition using batlike sonar.

    PubMed

    Vanderelst, Dieter; Steckel, Jan; Boen, Andre; Peremans, Herbert; Holderied, Marc W

    2016-08-02

    Echolocating bats have excellent spatial memory and are able to navigate to salient locations using bio-sonar. Navigating and route-following require animals to recognize places. Currently, it is mostly unknown how bats recognize places using echolocation. In this paper, we propose template based place recognition might underlie sonar-based navigation in bats. Under this hypothesis, bats recognize places by remembering their echo signature - rather than their 3D layout. Using a large body of ensonification data collected in three different habitats, we test the viability of this hypothesis assessing two critical properties of the proposed echo signatures: (1) they can be uniquely classified and (2) they vary continuously across space. Based on the results presented, we conclude that the proposed echo signatures satisfy both criteria. We discuss how these two properties of the echo signatures can support navigation and building a cognitive map.

  4. Low Frequency Sonar Signal Simulation

    DTIC Science & Technology

    2010-04-14

    participating in workshops. Task 3, Assess SST Propagation Accuracy at Low Frequencies: Determine accuracy domain of SST eigenray -based propagation model at... eigenrays ). The new algorithm, which is conceptually similar to the “point scatterer” approach, generates uncorrelated random Gaussian scattering...amplitudes for many cells (smaller than the sonar resolution) covering the bottom. These are combined with eigenray pairs and weighted by the angle

  5. Echo Statistics of Aggregations of Scatterers in a Random Waveguide: Application to Biologic Sonar Clutter

    DTIC Science & Technology

    2012-09-01

    matched-filtered data, while lower panels show matched-filtered, split - window-normalized results. An echo that is likely from a fish school is...and non-target scatterers within the water column, often limits active sonar system performance. Fish can constitute a significant portion of sonar...by fish with resonant gas-filled swimbladders can dominate over bottom or surface reverberation. This study examines the contributions of various

  6. Cetaceans and Naval Sonar: Behavioral Response as a Function of Sonar Frequency

    DTIC Science & Technology

    2008-01-01

    to the tag during launch suggested that use would be safe with the Dtag, but a test-Dtag package containing a TDR of identical weight and size to the...the six tags deployed with the pneumatic launch system, 3 were of the test-Dtag TDR , and 3 were with the Dtag. One Dtag was lost after deployment on...the MFAS exposure to whale subject gm08_150c. The whales positions are shown as filled circled, color-coded by the phase of the experiment. Note

  7. Computers improves sonar seabed maps

    SciTech Connect

    Not Available

    1984-05-01

    A software package for computer aided mapping of sonar (CAMOS) has been developed in Norway. It has automatic mosaic presentation, which produces fully scale-rectified side scan sonograms automatically plotted on geographical and UTM map grids. The program is the first of its kind in the world. The maps produced by this method are more accurate and detailed than those produced by conventional methods. The main applications of CAMOS are: seafloor mapping; pipeline route surveys; pipeline inspection surveys; platform site surveys; geological mapping and geotechnical investigations. With the aerial-photograph quality of the CAMOS maps, a more accurate and visual representation of the seabed is achieved.

  8. Place recognition using batlike sonar

    PubMed Central

    Vanderelst, Dieter; Steckel, Jan; Boen, Andre; Peremans, Herbert; Holderied, Marc W

    2016-01-01

    Echolocating bats have excellent spatial memory and are able to navigate to salient locations using bio-sonar. Navigating and route-following require animals to recognize places. Currently, it is mostly unknown how bats recognize places using echolocation. In this paper, we propose template based place recognition might underlie sonar-based navigation in bats. Under this hypothesis, bats recognize places by remembering their echo signature - rather than their 3D layout. Using a large body of ensonification data collected in three different habitats, we test the viability of this hypothesis assessing two critical properties of the proposed echo signatures: (1) they can be uniquely classified and (2) they vary continuously across space. Based on the results presented, we conclude that the proposed echo signatures satisfy both criteria. We discuss how these two properties of the echo signatures can support navigation and building a cognitive map. DOI: http://dx.doi.org/10.7554/eLife.14188.001 PMID:27481189

  9. Sonar Locator Systems

    NASA Technical Reports Server (NTRS)

    1985-01-01

    An underwater locator device called a Pinger is attached to an airplane's flight recorder for recovery in case of a crash. Burnett Electronics Pinger Model 512 resulted from a Burnett Electronics Laboratory, Inc./Langley Research Center contract for development of a search system for underwater mines. The Pinger's battery-powered transmitter is activated when immersed in water, and sends multidirectional signals for up to 500 hours. When a surface receiver picks up the signal, a diver can retrieve the pinger and the attached airplane flight recorder. Other pingers are used to track whales, mark underwater discoveries and assist oil drilling vessels.

  10. Using vertical Sidescan Sonar as a tool for seagrass cartography

    NASA Astrophysics Data System (ADS)

    Sánchez-Carnero, N.; Rodríguez-Pérez, D.; Couñago, E.; Aceña, S.; Freire, J.

    2012-12-01

    An acoustic method, a vertically oriented Sidescan Sonar (SSSv), is used to detect and map Posidonia oceanica meadows in the bay of Agua Amarga (SE of the Mediterranean coast of Spain). Sidescan sonar, among other active hydroacoustic techniques, has shown its ability to detect, map and monitor seagrass based on its acoustic backscatter; however, some limitations linked to its power based approach have been reported in the literature. Our method is based on the SSSv measurement of canopy height distribution, making the most use of the SSSv acoustic data and using existing algorithms as statistical mapping methods. The results show a spatially coherent and statistically consistent classification. The comparison with groundtruthing is difficult due to the steep variations in the seafloor cover found in the area of interest, nevertheless the validation is successful (proving low-order discrimination) in a zone with a large range of depth variations (0-25 m).

  11. Evolution: Fossil Ears and Underwater Sonar.

    PubMed

    Lambert, Olivier

    2016-08-22

    A key innovation in the history of whales was the evolution of a sonar system together with high-frequency hearing. Fossils of an archaic toothed whale's inner ear bones provide clues for a stepwise emergence of underwater echolocation ability.

  12. Remote characterizing diffuse hydrothermal flows using multi-beam sonar

    NASA Astrophysics Data System (ADS)

    Ivakin, A. N.; Jackson, D. R.; Bemis, K. G.; Xu, G.

    2015-12-01

    Multi-beam sonars are normally used for bottom bathymetry and backscatter intensity measurements, which provide a base for remotely characterizing the seabed. If not only sonar echo intensity (squared magnitude of acoustic pressure) but also the cross-correlation between successive echoes is measured, then temporal changes in sound speed in the near-bottom environment can be determined. This, in turn, allows estimation of the change of environmental parameters, e.g. temperature variations, as there is a simple linear relationship between sound speed and temperature changes. Stochastic modeling shows that the dependence of the echo decorrelation on the lag time has a relationship with the statistics of temperature variations above the seabed that determine their spatial and temporal scales, power spectra, and structure functions. This approach has been applied to quantify the bottom diffuse hydrothermal flow activity at the Main Endeavour Field on the Juan de Fuca Ridge using the Cabled Observatory Vent Imaging Sonar (COVIS) connected to the Ocean Network Canada's NEPTUNE observatory. In contrast to our previous work, which was focused on spatial imaging of acoustic decorrelation at fixed lag, here the lag dependence of the acoustic structure function is measured and analyzed. This allows extraction of additional parameters of temperature fluctuation statistics. A potential to map diffuse flow using a ROV/HOV is discussed.

  13. Ceteacean Social Behavioral Response to Sonar

    DTIC Science & Technology

    2014-09-30

    experimental sonar exposure in SOCAL-BRS (Risso’s dolphin )  Data-collection: Baseline social behavior - SOCAL-BRS projects (Risso’s dolphin ...playbacks using visual observation techniques 3 - Species evaluated: long-beaked common dolphin , bottlenose dolphin , killer whale - 2014: Design...data processing and analysis for Risso’s dolphin sonar response (SOCAL-BRS, Azores-Baseline) - Cross-study cooperation in data processing and analysis

  14. Reported Modality Preferences of Sonar Operators

    DTIC Science & Technology

    1991-02-01

    indicated a preference for the visual modality, which was similar in proportion for both STS and STG groups. On questions pertinent to sonar operation...most operators indicated a visual preference. However, on two of these items, proportionally more STS than STG operators showed an auditory...preference. Interestingly, 99% of all the subjects reported that present sonar systems are biased toward visual information. Yet, this survey showed that only

  15. AUV-12 Sonar Integration and Evaluation

    DTIC Science & Technology

    2010-02-26

    extension has been granted. Expenditures Authorized Title Labor ODC Com- mitted Total Funding Balance Start End AUV Sonar - CLIN-1 $214,144...36,520 $0 $250,664 $357,473 $106,809 01/29/09 01/29/10 AUV Sonar - CLIN-2 $869 $0 $0 $869 $74,385 $73,516 11/23/09 07/22/10 Total $215,012 $36,520 $0

  16. Parametric sonars for seafloor characterization

    NASA Astrophysics Data System (ADS)

    Caiti, Andrea; Bergem, Oddbjorn; Dybedal, Johnny

    1999-12-01

    Parametric sonars are instruments capable of transmitting acoustic signals in the water with a very narrow beam and almost no sidelobes. These features are exploited in this paper to define a methodology for quantitative estimation of the geo-acoustic and morphological properties of the uppermost seafloor sediment layer. The three major components of the approach are the parametric instrument itself; the modelling of the forward-propagation problem, with the use of the Kirchhoff approximation for surface scattering and of the small-perturbation theory for the volume scattering; and the definition of a criterion for comparison between data and model predictions, which is accomplished by a generalized time-frequency analysis. In this way the estimation becomes one of a model-based identification, or a model-based inverse problem. Results from a field trial in a shallow water area of the Mediterranean are shown, and compared with independently gathered ground truth.

  17. Source ranging with an underwater geographic point in non-cooperative bistatic sonar

    NASA Astrophysics Data System (ADS)

    Lee, Donghwa; Jung, Tae Jin; Lee, Kyun Kyung; Myung, Hyun

    2014-01-01

    Active sonar is divided into monostatic and bistatic sonar according to the relative positions of the source and the receiver. Bistatic sonar on modern submarines is classified into cooperative and non-cooperative operations. Cooperative operation uses an active signal of a friendly ship; therefore, source information is known a priori, whereas non-cooperative operation utilizes an active signal of the enemy, and hence, it is difficult to acquire source information, such as a source range, which is important for bistatic sonar operation. In order to overcome this difficulty, this paper proposes an estimation method for the source range that employs geographic information, and the utility of the source range estimation is evaluated. For the evaluation, we consider three error components. Then, the validity of the scheme is confirmed through theoretical error analysis and simulation study. The results show that geographic points that satisfy certain specific conditions can be used to estimate the source range within a range of tens of km in the simulation. Finally, we confirm that the receiver could estimate the source range from far away using non-cooperative bistatic sonar.

  18. Swath sonar mapping of Earth's submarine plate boundaries

    NASA Astrophysics Data System (ADS)

    Carbotte, S. M.; Ferrini, V. L.; Celnick, M.; Nitsche, F. O.; Ryan, W. B. F.

    2014-12-01

    The recent loss of Malaysia Airlines flight MH370 in an area of the Indian Ocean where less than 5% of the seafloor is mapped with depth sounding data (Smith and Marks, EOS 2014) highlights the striking lack of detailed knowledge of the topography of the seabed for much of the worlds' oceans. Advances in swath sonar mapping technology over the past 30 years have led to dramatic improvements in our capability to map the seabed. However, the oceans are vast and only an estimated 10% of the seafloor has been mapped with these systems. Furthermore, the available coverage is highly heterogeneous and focused within areas of national strategic priority and community scientific interest. The major plate boundaries that encircle the globe, most of which are located in the submarine environment, have been a significant focus of marine geoscience research since the advent of swath sonar mapping. While the location of these plate boundaries are well defined from satellite-derived bathymetry, significant regions remain unmapped at the high-resolutions provided by swath sonars and that are needed to study active volcanic and tectonic plate boundary processes. Within the plate interiors, some fossil plate boundary zones, major hotspot volcanoes, and other volcanic provinces have been the focus of dedicated research programs. Away from these major tectonic structures, swath mapping coverage is limited to sparse ocean transit lines which often reveal previously unknown deep-sea channels and other little studied sedimentary structures not resolvable in existing low-resolution global compilations, highlighting the value of these data even in the tectonically quiet plate interiors. Here, we give an overview of multibeam swath sonar mapping of the major plate boundaries of the globe as extracted from public archives. Significant quantities of swath sonar data acquired from deep-sea regions are in restricted-access international archives. Open access to more of these data sets would

  19. Automated Change Detection Using Synthetic Aperture Sonar Imagery

    DTIC Science & Technology

    2010-06-01

    using shadow outlining, scene matching using control-point matching, and visualization capabilities. This system was developed for sidescan sonar ...surveys using instrumentation such as the high-frequency Marine Sonic Technology sidescan sonar . In this paper, the authors describe modifications to...the sidescan -based system required to perform change detection using Synthetic Aperture Sonar (SAS) bottom imagery. Index Terms—Acoustic signal

  20. Experiments in Coherent Change Detection for Synthetic Aperture Sonar

    DTIC Science & Technology

    2010-06-01

    over time. ACD techniques, long used in airborne radar applications, are just beginning to be applied to sidescan sonar . In Coherent Change Detection...accurate geo- registration), the complexity of the propagation environment, and the radiometric inconsistencies of conventional sidescan sonars ...will follow suit. As conventional sidescan sonars exhibit resolution that degrades with range and are typically limited to creation of backscatter

  1. An autocorrelation model of bat sonar.

    PubMed

    Wiegrebe, Lutz

    2008-06-01

    Their sonar system allows echolocating bats to navigate with high skill through a complex, three- dimensional environment at high speed and low light. The auditory analysis of the echoes of their ultrasonic sounds requires a detailed comparison of the emission and echoes. Here an auditory model of bat sonar is introduced and evaluated against a set of psychophysical phantom-target, echo-acoustic experiments. The model consists of a relatively detailed simulation of auditory peripheral processing in the bat, Phyllostomus discolor, followed by a functional module consisting of a strobed, normalised, autocorrelation in each frequency channel. The model output is accumulated in a sonar image buffer. The model evaluation is based on the comparison of the image-buffer contents generated in individually simulated psychophysical trials. The model provides reasonably good predictions for both temporal and spectral behavioural sonar processing in terms of sonar delay-, roughness, and phase sensitivity and in terms of sensitivity to the temporal separations in two-front targets and the classification of spectrally divergent phantom targets.

  2. Representational learning for sonar ATR

    NASA Astrophysics Data System (ADS)

    Isaacs, Jason C.

    2014-06-01

    Learned representations have been shown to give hopeful results for solving a multitude of novel learning tasks, even though these tasks may be unknown when the model is being trained. A few notable examples include the techniques of topic models, deep belief networks, deep Boltzmann machines, and local discriminative Gaussians, all inspired by human learning. This self-learning of new concepts via rich generative models has emerged as a promising area of research in machine learning. Although there has been recent progress, existing computational models are still far from being able to represent, identify and learn the wide variety of possible patterns and struc- ture in real-world data. An important issue for further consideration is the use of unsupervised representations for novel underwater target recognition applications. This work will discuss and demonstrate the use of latent Dirichlet allocation and autoencoders for learning unsupervised representations of objects in sonar imagery. The objective is to make these representations more abstract and invariant to noise in the training distribution and improve performance.

  3. Prospects for using sonar for underwater archeology on the Yenisei: surveying a 19th century shipwreck

    NASA Astrophysics Data System (ADS)

    Goncharov, A. E.; Mednikov, D. M.; Karelin, N. M.; Nasyrov, I. R.

    2016-11-01

    Current progress in underwater archeology is based on a rich arsenal of high-tech appliances, among which sonar technology plays a key role; it enables scientists not only to detect submerged archeological objects, but to examine them in high definition without having to conduct diving operations or use expensive underwater unmanned vehicles. While the majority of sensational scientific discoveries using sonar have been made in saltwater environments, freshwater ones, rivers in particular, have seen limited activity. The river Yenisei in central Siberia contains an unrecorded number of shipwrecks that await being discovered and studied. In this article we focus on the peculiarities of using sonar for detecting archeological sites on the Yenisei. This article is based on the results of the 2016 expedition, which has determined the location of Thames, a 19th century British steam schooner which was wrecked on the Yenisei.

  4. Directional Receiver for Biomimetic Sonar System

    NASA Astrophysics Data System (ADS)

    Guarato, Francesco; Andrews, Heather; Windmill, James F.; Jackson, Joseph; Gachagan, Anthony

    An ultrasonic localization method for a sonar system equipped with an emitter and two directional receivers and inspired by bat echolocation uses knowledge of the beam pattern of the receivers to estimate target orientation. Rousettus leschenaultii's left ear constitutes the model for the design of the optimal receiver for this sonar system and 3D printing was used to fabricate receiver structures comprising of two truncated cones with an elliptical external perimeter and a parabolic flare rate in the upper part. Measurements show one receiver has a predominant lobe in the same region and with similar attenuation values as the bat ear model. The final sonar system is to be mounted on vehicular and aerial robots which require remote control for motion and sensors for estimation of each robot's location.

  5. Aerial ultrasonic micro Doppler sonar detection range in outdoor environments.

    PubMed

    Bradley, Marshall; Sabatier, James M

    2012-03-01

    Current research demonstrates that micro Doppler sonar has the capability to uniquely identify the presence of a moving human, making it an attractive component in surveillance systems for border security applications. Primary environmental factors that limit sonar performance are two-way spreading losses, ultrasonic absorption, and backscattered energy from the ground that appears at zero Doppler shift in the sonar signal processor. Spectral leakage from the backscatter component has a significant effect on sonar performance for slow moving targets. Sonar performance is shown to rapidly decay as the sensor is moved closer to the ground due to increasing surface backscatter levels.

  6. Sonar array processing borrows from geophysics

    SciTech Connect

    Chen, K.

    1989-09-01

    The author reports a recent advance in sonar signal processing that has potential military application. It improves signal extraction by modifying a technique devised by a geophysicist. Sonar signal processing is used to track submarine and surface targets, such as aircraft carriers, oil tankers, and, in commercial applications, schools of fish or sunken treasure. Similar signal-processing techniques help radio astronomers track galaxies, physicians see images of the body interior, and geophysicists map the ocean floor or find oil. This hydrid technique, applied in an experimental system, can help resolve strong signals as well as weak ones in the same step.

  7. High thresholds for avoidance of sonar by free-ranging long-finned pilot whales (Globicephala melas).

    PubMed

    Antunes, R; Kvadsheim, P H; Lam, F P A; Tyack, P L; Thomas, L; Wensveen, P J; Miller, P J O

    2014-06-15

    The potential effects of exposing marine mammals to military sonar is a current concern. Dose-response relationships are useful for predicting potential environmental impacts of specific operations. To reveal behavioral response thresholds of exposure to sonar, we conducted 18 exposure/control approaches to 6 long-finned pilot whales. Source level and proximity of sonar transmitting one of two frequency bands (1-2 kHz and 6-7 kHz) were increased during exposure sessions. The 2-dimensional movement tracks were analyzed using a changepoint method to identify the avoidance response thresholds which were used to estimate dose-response relationships. No support for an effect of sonar frequency or previous exposures on the probability of response was found. Estimated response thresholds at which 50% of population show avoidance (SPLmax=170 dB re 1 μPa, SELcum=173 dB re 1 μPa(2) s) were higher than previously found for other cetaceans. The US Navy currently uses a generic dose-response relationship to predict the responses of cetaceans to naval active sonar, which has been found to underestimate behavioural impacts on killer whales and beaked whales. The navy curve appears to match more closely our results with long-finned pilot whales, though it might underestimate the probability of avoidance for pilot-whales at long distances from sonar sources.

  8. Spatial perception and adaptive sonar behavior.

    PubMed

    Aytekin, Murat; Mao, Beatrice; Moss, Cynthia F

    2010-12-01

    Bat echolocation is a dynamic behavior that allows for real-time adaptations in the timing and spectro-temporal design of sonar signals in response to a particular task and environment. To enable detailed, quantitative analyses of adaptive sonar behavior, echolocation call design was investigated in big brown bats, trained to rest on a stationary platform and track a tethered mealworm that approached from a starting distance of about 170 cm in the presence of a stationary sonar distracter. The distracter was presented at different angular offsets and distances from the bat. The results of this study show that the distance and the angular offset of the distracter influence sonar vocalization parameters of the big brown bat, Eptesicus fuscus. Specifically, the bat adjusted its call duration to the closer of two objects, distracter or insect target, and the magnitude of the adjustment depended on the angular offset of the distracter. In contrast, the bat consistently adjusted its call rate to the distance of the insect, even when this target was positioned behind the distracter. The results hold implications for understanding spatial information processing and perception by echolocation.

  9. Trajectory Sonar Perception in the Ligurian Sea

    DTIC Science & Technology

    2006-01-01

    A typical marine robot displaces 50-500kg, transmits its sonar 3-10 times per second, and is perturbed by waves with periods on the order of 5-30...Transactions on Pattern Analysis and Machine Intelligence, PAMI-12(6):560–569, June 1990. 2. R. A. Brooks. Cambrian Intelligence: The Early History of the New

  10. Automatic seagrass pattern identification on sonar images

    NASA Astrophysics Data System (ADS)

    Rahnemoonfar, Maryam; Rahman, Abdullah

    2016-05-01

    Natural and human-induced disturbances are resulting in degradation and loss of seagrass. Freshwater flooding, severe meteorological events and invasive species are among the major natural disturbances. Human-induced disturbances are mainly due to boat propeller scars in the shallow seagrass meadows and anchor scars in the deeper areas. Therefore, there is a vital need to map seagrass ecosystems in order to determine worldwide abundance and distribution. Currently there is no established method for mapping the pothole or scars in seagrass. One of the most precise sensors to map the seagrass disturbance is side scan sonar. Here we propose an automatic method which detects seagrass potholes in sonar images. Side scan sonar images are notorious for having speckle noise and uneven illumination across the image. Moreover, disturbance presents complex patterns where most segmentation techniques will fail. In this paper, by applying mathematical morphology technique and calculating the local standard deviation of the image, the images were enhanced and the pothole patterns were identified. The proposed method was applied on sonar images taken from Laguna Madre in Texas. Experimental results show the effectiveness of the proposed method.

  11. Introduction to Sonar, Navy Training Course.

    ERIC Educational Resources Information Center

    Naval Personnel Program Support Activity, Washington, DC.

    Fundamentals of sonar systems are presented in this book, prepared for both regular navy and naval reserve personnel who are seeking advancement in rating. An introductory description is first made of submarines and antisubmarine units. Determination of underwater targets is analyzed from the background of true and relative bearings, true and…

  12. How do tiger moths jam bat sonar?

    PubMed

    Corcoran, Aaron J; Barber, Jesse R; Hristov, Nickolay I; Conner, William E

    2011-07-15

    The tiger moth Bertholdia trigona is the only animal in nature known to defend itself by jamming the sonar of its predators - bats. In this study we analyzed the three-dimensional flight paths and echolocation behavior of big brown bats (Eptesicus fuscus) attacking B. trigona in a flight room over seven consecutive nights to determine the acoustic mechanism of the sonar-jamming defense. Three mechanisms have been proposed: (1) the phantom echo hypothesis, which states that bats misinterpret moth clicks as echoes; (2) the ranging interference hypothesis, which states that moth clicks degrade the bats' precision in determining target distance; and (3) the masking hypothesis, which states that moth clicks mask the moth echoes entirely, making the moth temporarily invisible. On nights one and two of the experiment, the bats appeared startled by the clicks; however, on nights three through seven, the bats frequently missed their prey by a distance predicted by the ranging interference hypothesis (∼15-20 cm). Three-dimensional simulations show that bats did not avoid phantom targets, and the bats' ability to track clicking prey contradicts the predictions of the masking hypothesis. The moth clicks also forced the bats to reverse their stereotyped pattern of echolocation emissions during attack, even while bats continued pursuit of the moths. This likely further hinders the bats' ability to track prey. These results have implications for the evolution of sonar jamming in tiger moths, and we suggest evolutionary pathways by which sonar jamming may have evolved from other tiger moth defense mechanisms.

  13. Assessment of Modeled Received Sound Pressure Levels and Movements of Satellite-Tagged Odontocetes Exposed to Mid-Frequency Active Sonar at the Pacific Missile Range Facility: February 2011 Through February 2013

    DTIC Science & Technology

    2014-05-30

    PMRF so that animal movements and diving behavior could be measured both before and during sonar use. PMRF PAM data and tag data were used in this...initial analysis to estimate exposure levels for tagged animals and determine whether any large-scale movements of these animals may have occurred in...range hydrophones), ship positions at time of transmissions (provided by PMRF) and animal locations (determined from satellite tag positions) allowed

  14. Suppression of emission rates improves sonar performance by flying bats.

    PubMed

    Adams, Amanda M; Davis, Kaylee; Smotherman, Michael

    2017-01-31

    Echolocating bats face the challenge of actively sensing their environment through their own emissions, while also hearing calls and echoes of nearby conspecifics. How bats mitigate interference is a long-standing question that has both ecological and technological implications, as biosonar systems continue to outperform man-made sonar systems in noisy, cluttered environments. We recently showed that perched bats decreased calling rates in groups, displaying a behavioral strategy resembling the back-off algorithms used in artificial communication networks to optimize information throughput at the group level. We tested whether free-tailed bats (Tadarida brasiliensis) would employ such a coordinated strategy while performing challenging flight maneuvers, and report here that bats navigating obstacles lowered emission rates when hearing artificial playback of another bat's calls. We measured the impact of acoustic interference on navigation performance and show that the calculated reductions in interference rates are sufficient to reduce interference and improve obstacle avoidance. When bats flew in pairs, each bat responded to the presence of the other as an obstacle by increasing emissions, but hearing the sonar emissions of the nearby bat partially suppressed this response. This behavior supports social cohesion by providing a key mechanism for minimizing mutual interference.

  15. Suppression of emission rates improves sonar performance by flying bats

    PubMed Central

    Adams, Amanda M.; Davis, Kaylee; Smotherman, Michael

    2017-01-01

    Echolocating bats face the challenge of actively sensing their environment through their own emissions, while also hearing calls and echoes of nearby conspecifics. How bats mitigate interference is a long-standing question that has both ecological and technological implications, as biosonar systems continue to outperform man-made sonar systems in noisy, cluttered environments. We recently showed that perched bats decreased calling rates in groups, displaying a behavioral strategy resembling the back-off algorithms used in artificial communication networks to optimize information throughput at the group level. We tested whether free-tailed bats (Tadarida brasiliensis) would employ such a coordinated strategy while performing challenging flight maneuvers, and report here that bats navigating obstacles lowered emission rates when hearing artificial playback of another bat’s calls. We measured the impact of acoustic interference on navigation performance and show that the calculated reductions in interference rates are sufficient to reduce interference and improve obstacle avoidance. When bats flew in pairs, each bat responded to the presence of the other as an obstacle by increasing emissions, but hearing the sonar emissions of the nearby bat partially suppressed this response. This behavior supports social cohesion by providing a key mechanism for minimizing mutual interference. PMID:28139707

  16. Acoustic Image Models for Navigation with Forward-Looking Sonars

    DTIC Science & Technology

    2008-12-01

    used for altitude and velocity over ground estimation. For mapping, the REMUS uses a Marine Sonics 900 kHz sidescan sonar . The Marine Sonics 900 has...and J. Bell. An Automatic Approach to the Detection and Extraction of Mine Features in Sidescan Sonar . IEEE Journal of Oceanic Engineering, 28:90–105...2003. [18] S. Reed, Y. Petillot, and J. Bell. Automated approach to classication of mine-like objects in sidescan sonar using highlight and shadow

  17. Bearing Estimation Uncertainties for the Volume Search Sonar

    DTIC Science & Technology

    2009-08-31

    II bathymetric sidescan sonar system”, IEEE Journal of Oceanic Engineering, 17(3), 239-251, 1992. R. O. Nielsen, “Accuracy of angle estimation with...shows potential for detecting variations in sediment type in much the same manner that a sidescan sonar detects these variations. However, this data...code) 31/08/2009 Final / Technical 2003 - Aug. 2008 Acoustic Signal Processing for Ocean Mapping Applications With The Volume Search Sonar (VSS

  18. Modeling a 300 kHz Bathymetric Sonar System

    DTIC Science & Technology

    1992-09-01

    AD-A257 378 /7 Modeling A 300 kHz Bathymetric Sonar System by Kenneth Alan Malmquist B.S., Drexel University, Philadelphia (1985) Submitted in...Massachusetts Institute of Technology/ Woods Hole Oceanographic Institution 92-28033 Vll1 Nlf • 92 BLANK PAR Modeling A 300 kIz Bathymetric Sonar System by...Deep Submergence Laboratory has developed a family of calibrated high frequency bathymetric sonar systems for underwater survey. It is useful to have a

  19. Sonar sensor models and their application to mobile robot localization.

    PubMed

    Burguera, Antoni; González, Yolanda; Oliver, Gabriel

    2009-01-01

    This paper presents a novel approach to mobile robot localization using sonar sensors. This approach is based on the use of particle filters. Each particle is augmented with local environment information which is updated during the mission execution. An experimental characterization of the sonar sensors used is provided in the paper. A probabilistic measurement model that takes into account the sonar uncertainties is defined according to the experimental characterization. The experimental results quantitatively evaluate the presented approach and provide a comparison with other localization strategies based on both the sonar and the laser. Some qualitative results are also provided for visual inspection.

  20. The sonar aperture and its neural representation in bats.

    PubMed

    Heinrich, Melina; Warmbold, Alexander; Hoffmann, Susanne; Firzlaff, Uwe; Wiegrebe, Lutz

    2011-10-26

    As opposed to visual imaging, biosonar imaging of spatial object properties represents a challenge for the auditory system because its sensory epithelium is not arranged along space axes. For echolocating bats, object width is encoded by the amplitude of its echo (echo intensity) but also by the naturally covarying spread of angles of incidence from which the echoes impinge on the bat's ears (sonar aperture). It is unclear whether bats use the echo intensity and/or the sonar aperture to estimate an object's width. We addressed this question in a combined psychophysical and electrophysiological approach. In three virtual-object playback experiments, bats of the species Phyllostomus discolor had to discriminate simple reflections of their own echolocation calls differing in echo intensity, sonar aperture, or both. Discrimination performance for objects with physically correct covariation of sonar aperture and echo intensity ("object width") did not differ from discrimination performances when only the sonar aperture was varied. Thus, the bats were able to detect changes in object width in the absence of intensity cues. The psychophysical results are reflected in the responses of a population of units in the auditory midbrain and cortex that responded strongest to echoes from objects with a specific sonar aperture, regardless of variations in echo intensity. Neurometric functions obtained from cortical units encoding the sonar aperture are sufficient to explain the behavioral performance of the bats. These current data show that the sonar aperture is a behaviorally relevant and reliably encoded cue for object size in bat sonar.

  1. Color and Grey Scale in Sonar Displays

    NASA Technical Reports Server (NTRS)

    Kraiss, K. F.; Kuettelwesch, K. H.

    1984-01-01

    In spite of numerous publications 1 it is still rather unclear, whether color is of any help in sonar displays. The work presented here deals with a particular type of sonar data, i.e., LOFAR-grams (low frequency analysing and recording) where acoustic sensor data are continuously written as a time-frequency plot. The question to be answered quantitatively is, whether color coding does improve target detection when compared with a grey scale code. The data show significant differences in receiver-operating characteristics performance for the selected codes. In addition it turned out, that the background noise level affects the performance dramatically for some color codes, while others remain stable or even improve. Generally valid rules are presented on how to generate useful color scales for this particular application.

  2. Mapping with side-scan sonar

    SciTech Connect

    Prior, D.B.; Coleman, J.M.; Roberts, H.H.

    1981-04-01

    The use of sideways scanning sonar as a technique for detailed sea-floor mapping is described in this article. Sea-floor mapping of the continental shelf is becoming increasingly necessary for the development of oil and gas resources. More recently attempts are being made to extend the survey capabilities to deeper water shelf margins, slopes, and basins. Conventional systems, digital systems, survey ranges, data processing, mosaics, and applications are discussed. (DMC)

  3. Ceteacean Social Behavioral Response to Sonar

    DTIC Science & Technology

    2013-09-30

    responses to sonar signals and other stimuli (tagging effort, killer whale playbacks) as well as baseline behavior, are studied within the larger... killer whale vocalizations in 3S2 - Response to tagging and vessel noise exposure in Azores-Baseline - Species: Northern bottlenose whale , Risso’s...common dolphin, bottlenose dolphin, killer whale  Cross-study implementation of group sampling methodology - Protocols used in four BRS studies

  4. Sonar Transducer Reliability Improvement Program (STRIP).

    DTIC Science & Technology

    1981-04-01

    surfaces of PZT ceramic. The ceramic surface tends to be the weakest part of the insulation system of a sonar transducer. The highest typical electrical...comparable value obtained with uncoated ceramic. Also, the breakdown voltage on the surface ( flashover ) was increased only a small amount, typically less...coating/ surface interface, and some were combinations. A coating material often touted as exceptionally 3ood is Parylene, which is vacuum deposited

  5. Sonar Transducer Reliability Improvement Program FY80.

    DTIC Science & Technology

    1980-01-01

    band Threshold - less than ±2 dB variation from the specified value over operational frequency band The Sonar Transducer Reliability Improvement...were Qetiker preformed clamps, Band -It preformed clamps, and Band -It Scru-Loct retrofittable clamps. *TASK 5: Manufacture Instrumented Connectors Under...cycle 6 PRE-kORM 10 PU-U Cable bond failure, Remove from test after DSS-3 under gap in clamp cycle 5 OETIKER 11 N-G " ring leakage was Removed from

  6. Field Calibration Procedures for Multibeam Sonar Systems

    DTIC Science & Technology

    1998-06-01

    include multibeam sonar transducers, light detection and ranging ( LIDAR ) surveys, acoustic seafloor classification systems, sub-bottom profilers, and... DTM ) of the reference surface is created from the cleaned data, and an averaging gridding algorithm is used to smooth the data. The gridding size...should be no larger than the average footprint of the inner beams. Using large vertical exaggeration, the DTM should be observed on 3-D visualization

  7. Velocity Estimation Using Forward Looking Sonar

    DTIC Science & Technology

    2007-03-01

    Looking Sonar GPS Global Positioning System GWOT Global War on Terrorism ISR Intelligence, Surveillance, and Reconnaissance LBL Long Base-Line NL...inputs from equipment such as long base-line ( LBL ) transponders, accelerometers, and gyroscopes to track how the vehicle has moved from the last known...includes a compass, the above-mentioned ADCP to provide speed over ground when ground lock is available, and an acoustic LBL system to correct

  8. Radar and sonar probing of rocks

    SciTech Connect

    Unterberger, R.R.

    1983-03-01

    The purpose of this paper is to summarize the research of the past sixteen years on methods of probing into solid rock. For these purposes, there are three completely different systems: radar, sonar, and nonlinear sonar. In dry salt all of the systems work. Five radar systems of different frequencies have been used to probe salt for different purposes and with different resolutions. Distances penetrated were from almost 2000 meters to under one 1 meter. With some moisture in the rock, the low frequency Alpha radar system is best because it operates at the frequency of the minimum in loss tangent for water. Sonar systems are used for even more water in the rock. Ranges of one to 300 meters have been obtained in salt with the lower ranges (to 100m) being obtainable is salt with the most water in it. Using one or more of the probing systems, the authors have detected, and ranged to, salt dome flanks, the top of salt, sandstone, anhydrite and sylvite stringers in salt, fractures in salt and water-filled fractures. We have also detected old boreholes in salt pillars, and measured the range and direction to them.

  9. Measurement of stream channel habitat using sonar

    USGS Publications Warehouse

    Flug, M.; Seitz, H.; Scott, J.

    1998-01-01

    An efficient and low cost technique using a sonar system was evaluated for describing channel geometry and quantifying inundated area in a large river. The boat-mounted portable sonar equipment was used to record water depths and river width measurements for direct storage on a laptop computer. The field data collected from repeated traverses at a cross-section were evaluated to determine the precision of the system and field technique. Results from validation at two different sites showed average sample standard deviations (S.D.s) of 0.12 m for these complete cross-sections, with coefficient of variations of 10%. Validation using only the mid-channel river cross-section data yields an average sample S.D. of 0.05 m, with a coefficient of variation below 5%, at a stable and gauged river site using only measurements of water depths greater than 0.6 m. Accuracy of the sonar system was evaluated by comparison to traditionally surveyed transect data from a regularly gauged site. We observed an average mean squared deviation of 46.0 cm2, considering only that portion of the cross-section inundated by more than 0.6 m of water. Our procedure proved to be a reliable, accurate, safe, quick, and economic method to record river depths, discharges, bed conditions, and substratum composition necessary for stream habitat studies. ?? 1998 John Wiley & Sons, Ltd.

  10. Phase sensitivity in bat sonar revisited.

    PubMed

    Schörnich, Sven; Wiegrebe, Lutz

    2008-01-01

    An echolocating bat produces echoes consisting of the convolution of echolocation call and the impulse response (IR) of the ensonified object. A crucial question in animal sonar is whether bats are able to extract this IR from the echo. The bat inner ear generates a frequency representation of call and echo and IR extraction in the frequency domain requires accurate analysis of both magnitude and phase information. Previous studies investigating the phase sensitivity of bats using a jitter paradigm reported a temporal acuity down to 10 ns, suggesting perfect sonar phase representation. In a phantom-target playback experiment, we investigate the perceptual phase sensitivity of the bat Phyllostomus discolor using a novel approach: instead of manipulating IR phase by changing IR delay (jitter paradigm), we randomized IR phase and thus lengthened the IR over time, leaving the magnitude spectrum unchanged. Our results show that phase sensitivity, as reflected in the analysis of signal duration, appears to be much lower than phase sensitivity, as reflected in the analysis of signal onset. The current data indicate that different temporal aspects of sonar processing are encoded with very different temporal resolution and thus an overall claim of "phase sensitivity" as such cannot be maintained.

  11. Processing of SeaMARC swath sonar imagery

    SciTech Connect

    Pratson, L.; Malinverno, A.; Edwards, M.; Ryan, W. )

    1990-05-01

    Side-scan swath sonar systems have become an increasingly important means of mapping the sea floor. Two such systems are the deep-towed, high-resolution SeaMARC I sonar, which has a variable swath width of up to 5 km, and the shallow-towed, lower-resolution SeaMARC II sonar, which has a swath width of 10 km. The sea-floor imagery of acoustic backscatter output by the SeaMARC sonars is analogous to aerial photographs and airborne side-looking radar images of continental topography. Geologic interpretation of the sea-floor imagery is greatly facilitated by image processing. Image processing of the digital backscatter data involves removal of noise by median filtering, spatial filtering to remove sonar scans of anomalous intensity, across-track corrections to remove beam patterns caused by nonuniform response of the sonar transducers to changes in incident angle, and contrast enhancement by histogram equalization to maximize the available dynamic range. Correct geologic interpretation requires submarine structural fabrics to be displayed in their proper locations and orientations. Geographic projection of sea-floor imagery is achieved by merging the enhanced imagery with the sonar vehicle navigation and correcting for vehicle attitude. Co-registration of bathymetry with sonar imagery introduces sea-floor relief and permits the imagery to be displayed in three-dimensional perspectives, furthering the ability of the marine geologist to infer the processes shaping formerly hidden subsea terrains.

  12. Introduction to Sonar, Naval Education and Training Command. Revised Edition.

    ERIC Educational Resources Information Center

    Naval Education and Training Command, Pensacola, FL.

    This Rate Training Manual (RTM) and Nonresident Career Course form a self-study package for those U.S. Navy personnel who are seeking advancement in the Sonar Technician Rating. Among the requirements of the rating are the abilities to obtain and interpret underwater data, operate and maintain upkeep of sonar equipment, and interpret target and…

  13. Timing matters: sonar call groups facilitate target localization in bats.

    PubMed

    Kothari, Ninad B; Wohlgemuth, Melville J; Hulgard, Katrine; Surlykke, Annemarie; Moss, Cynthia F

    2014-01-01

    To successfully negotiate a cluttered environment, an echolocating bat must control the timing of motor behaviors in response to dynamic sensory information. Here we detail the big brown bat's adaptive temporal control over sonar call production for tracking prey, moving predictably or unpredictably, under different experimental conditions. We studied the adaptive control of vocal-motor behaviors in free-flying big brown bats, Eptesicus fuscus, as they captured tethered and free-flying insects, in open and cluttered environments. We also studied adaptive sonar behavior in bats trained to track moving targets from a resting position. In each of these experiments, bats adjusted the features of their calls to separate target and clutter. Under many task conditions, flying bats produced prominent sonar sound groups identified as clusters of echolocation pulses with relatively stable intervals, surrounded by longer pulse intervals. In experiments where bats tracked approaching targets from a resting position, bats also produced sonar sound groups, and the prevalence of these sonar sound groups increased when motion of the target was unpredictable. We hypothesize that sonar sound groups produced during flight, and the sonar call doublets produced by a bat tracking a target from a resting position, help the animal resolve dynamic target location and represent the echo scene in greater detail. Collectively, our data reveal adaptive temporal control over sonar call production that allows the bat to negotiate a complex and dynamic environment.

  14. Timing matters: sonar call groups facilitate target localization in bats

    PubMed Central

    Kothari, Ninad B.; Wohlgemuth, Melville J.; Hulgard, Katrine; Surlykke, Annemarie; Moss, Cynthia F.

    2014-01-01

    To successfully negotiate a cluttered environment, an echolocating bat must control the timing of motor behaviors in response to dynamic sensory information. Here we detail the big brown bat's adaptive temporal control over sonar call production for tracking prey, moving predictably or unpredictably, under different experimental conditions. We studied the adaptive control of vocal-motor behaviors in free-flying big brown bats, Eptesicus fuscus, as they captured tethered and free-flying insects, in open and cluttered environments. We also studied adaptive sonar behavior in bats trained to track moving targets from a resting position. In each of these experiments, bats adjusted the features of their calls to separate target and clutter. Under many task conditions, flying bats produced prominent sonar sound groups identified as clusters of echolocation pulses with relatively stable intervals, surrounded by longer pulse intervals. In experiments where bats tracked approaching targets from a resting position, bats also produced sonar sound groups, and the prevalence of these sonar sound groups increased when motion of the target was unpredictable. We hypothesize that sonar sound groups produced during flight, and the sonar call doublets produced by a bat tracking a target from a resting position, help the animal resolve dynamic target location and represent the echo scene in greater detail. Collectively, our data reveal adaptive temporal control over sonar call production that allows the bat to negotiate a complex and dynamic environment. PMID:24860509

  15. Cetaceans and Naval Sonar: Behavioral Response as a Function of Sonar Frequency

    DTIC Science & Technology

    2010-09-30

    labeled on the left, and the type of sonar exposure is shown by color. The dose - response curve below each histogram is the harassment dose - response curve currently...1) with indications that weighting the received levels do not improve the steepness of the dose - response curve . The results of this dose-response

  16. Cetaceans and Naval Sonar: Behavioral Response as a Function of Sonar Frequency

    DTIC Science & Technology

    2011-09-30

    Nowacek, D. P., Thorne , L. H., Johnston, D. W., Tyack, P. L. 2007. Responses of cetaceans to anthropogenic noise. Mammal Review 37, 81-115...Tyack PL, Bird A, Miller PJO. (submitted) Vocal matching of sonar signals by long-finned pilot whales (Globicephala melas). Naturwissenschaften

  17. Offshore exploration and platform siting by imaging Sonar

    SciTech Connect

    Feder, A.M.

    1986-03-17

    Sonar, an acronym for sonic azimuth and ranging (some say ''sonic detection and ranging''), is the name of a type of remote sensor that was developed in World War II for antisubmarine warfare purposes. The principles of the sensor system are simple in that it broadcasts a focused (shaped) sonic pulse through the water (transmission medium), then receives the echo of that pulse and processes this signal for its information content. Hence, Sonar system principles are highly analagous to those of radar. Post-World War II saw development of Sonar probes that provided some success in determining sea floor materials composition and condition (e.g., subbottom profilers). The major advance, however, was with the advent of digital computation systems. These permitted the coupling of Sonar azimuth and range components to provide ''x'' and ''y'' coordinates for each echo location, or ''z'' value. This advance is seeing a proliferation of different types of imaging Sonar systems and performances.

  18. Spawning behaviour of Allis shad Alosa alosa: new insights based on imaging sonar data.

    PubMed

    Langkau, M C; Clavé, D; Schmidt, M B; Borcherding, J

    2016-06-01

    Spawning behaviour of Alosa alosa was observed by high resolution imaging sonar. Detected clouds of sexual products and micro bubbles served as a potential indicator of spawning activity. Peak spawning time was between 0130 and 0200 hours at night. Increasing detections over three consecutive nights were consistent with sounds of mating events (bulls) assessed in hearing surveys in parallel to the hydro acoustic detection. In 70% of the analysed mating events there were no additional A. alosa joining the event whilst 70% of the mating events showed one or two A. alosa leaving the cloud. In 31% of the analysed mating events, however, three or more A. alosa were leaving the clouds, indicating that matings are not restricted to a pair. Imaging sonar is suitable for monitoring spawning activity and behaviour of anadromous clupeids in their spawning habitats.

  19. Mechanical charactization of sonar window materials

    SciTech Connect

    DeTeresa, S.J.; Groves, S.E.; Harwood, P.J.; Sanchez, R.J.

    1996-03-25

    The three-dimensional mechanical behavior of thick Spectra/epoxy sonar window materials containing various special materials is summarized in this report. Three different materials, which were fabricated by two companies known as `A` and `B` were received from the Naval Warfare Center. The three materials designated `A with microspheres (A micron),` `A without microspheres (A),` and `B` were measured for all properties. The total number of tests was reduced through the assumption that the two orthogonal, in-place directions were identical. Consequently, these materials should have only six independent elastic variables. The measured constants and strengths are given.

  20. Sonar Transducer Reliability Improvement Program FY 80

    DTIC Science & Technology

    1980-10-01

    Polyphenylene Sulfide 15,320 23,000 Nylon 6/10 14,070 26,000 High-Strength Nylon (ZYTEL) 11,270 24,000 Amorphous Nylon 14,139 25,000 PBT Polyester...transducer receiving sensitivity Goal -- less than ±1 dB variation from the specified value over operational frequency band . Threshold - less than ±2 dB...variation from the specified value over operational feequency band . rhe Sonar Transducer Reliability Impruvemen: Program (STRIP) is a part of Program

  1. Sonar Test and Test Instrumentation Support.

    DTIC Science & Technology

    1979-03-29

    CONTRACT OR GRANT NUMBER(s) Nool40-76-c-6487 Dudley D. Baker et al. S. PERFORMING ORGANIZATION NAME AND ADDRESS 10 . PROGRAM ELEMENT. PROJECT, TASK AREA...Date Entered) TABLE OF CONTENTS Page I. INTRODUCTION 1 II. TRF, AN/FQM- 10 (V), AND AN/WQM-5 FIELD SUPPORT 3 A. Pressure Vessel Stuffing Tubes 3 B. AN/FQM...Test Set 9 * , D. SACS Support 10 1. Hardware Documentation 10 2. Software Documentation 10 3. Sonar Controller Installation 10 4. AN/SQS-35/38 Study 11

  2. Detecting Atlantic herring by parametric sonar.

    PubMed

    Godo, Olav Rune; Foote, Kenneth G; Dybedal, Johnny; Tenningen, Eirik; Patel, Ruben

    2010-04-01

    The difference-frequency band of the Kongsberg TOPAS PS18 parametric sub-bottom profiling sonar, nominally 1-6 kHz, is being used to observe Atlantic herring. Representative TOPAS echograms of herring layers and schools observed in situ in December 2008 and November 2009 are presented. These agree well with echograms of volume backscattering strength derived simultaneously with the narrowband Simrad EK60/18- and 38-kHz scientific echo sounder, also giving insight into herring avoidance behavior in relation to survey vessel passage. Progress in rendering the TOPAS echograms quantitative is described.

  3. Sonar beam dynamics in leaf-nosed bats.

    PubMed

    Linnenschmidt, Meike; Wiegrebe, Lutz

    2016-07-07

    Ultrasonic emissions of bats are directional and delimit the echo-acoustic space. Directionality is quantified by the aperture of the sonar beam. Recent work has shown that bats often widen their sonar beam when approaching movable prey or sharpen their sonar beam when navigating through cluttered habitats. Here we report how nose-emitting bats, Phyllostomus discolor, adjust their sonar beam to object distance. First, we show that the height and width of the bats sonar beam, as imprinted on a parabolic 45 channel microphone array, varies even within each animal and this variation is unrelated to changes in call level or spectral content. Second, we show that these animals are able to systematically decrease height and width of their sonar beam while focusing on the approaching object. Thus it appears that sonar beam sharpening is a further, facultative means of reducing search volume, likely to be employed by stationary animals when the object position is close and unambiguous. As only half of our individuals sharpened their beam onto the approaching object we suggest that this strategy is facultative, under voluntary control, and that beam formation is likely mediated by muscular control of the acoustic aperture of the bats' nose leaf.

  4. Sonar beam dynamics in leaf-nosed bats

    PubMed Central

    Linnenschmidt, Meike; Wiegrebe, Lutz

    2016-01-01

    Ultrasonic emissions of bats are directional and delimit the echo-acoustic space. Directionality is quantified by the aperture of the sonar beam. Recent work has shown that bats often widen their sonar beam when approaching movable prey or sharpen their sonar beam when navigating through cluttered habitats. Here we report how nose-emitting bats, Phyllostomus discolor, adjust their sonar beam to object distance. First, we show that the height and width of the bats sonar beam, as imprinted on a parabolic 45 channel microphone array, varies even within each animal and this variation is unrelated to changes in call level or spectral content. Second, we show that these animals are able to systematically decrease height and width of their sonar beam while focusing on the approaching object. Thus it appears that sonar beam sharpening is a further, facultative means of reducing search volume, likely to be employed by stationary animals when the object position is close and unambiguous. As only half of our individuals sharpened their beam onto the approaching object we suggest that this strategy is facultative, under voluntary control, and that beam formation is likely mediated by muscular control of the acoustic aperture of the bats’ nose leaf. PMID:27384865

  5. Sonar target enhancement by shrinkage of incoherent wavelet coefficients.

    PubMed

    Hunter, Alan J; van Vossen, Robbert

    2014-01-01

    Background reverberation can obscure useful features of the target echo response in broadband low-frequency sonar images, adversely affecting detection and classification performance. This paper describes a resolution and phase-preserving means of separating the target response from the background reverberation noise using a coherence-based wavelet shrinkage method proposed recently for de-noising magnetic resonance images. The algorithm weights the image wavelet coefficients in proportion to their coherence between different looks under the assumption that the target response is more coherent than the background. The algorithm is demonstrated successfully on experimental synthetic aperture sonar data from a broadband low-frequency sonar developed for buried object detection.

  6. Cetaceans and Naval Sonar: Behavioral Response as a Function of Sonar Frequency

    DTIC Science & Technology

    2009-09-30

    initially motivated by observations of possible killer whale (Orcinus orca) reactions to sonars, in the Vestfjord basin of Norway and the USS Shoup...that works with killer whales . The high public profile of killer whales and the overlap of their habitats with operational areas make it likely...that incidents will continue to occur worldwide. The killer whale population involved in the USS Shoup incident has been listed as endangered under the

  7. A micro-Doppler sonar for acoustic surveillance in sensor networks

    NASA Astrophysics Data System (ADS)

    Zhang, Zhaonian

    Wireless sensor networks have been employed in a wide variety of applications, despite the limited energy and communication resources at each sensor node. Low power custom VLSI chips implementing passive acoustic sensing algorithms have been successfully integrated into an acoustic surveillance unit and demonstrated for detection and location of sound sources. In this dissertation, I explore active and passive acoustic sensing techniques, signal processing and classification algorithms for detection and classification in a multinodal sensor network environment. I will present the design and characterization of a continuous-wave micro-Doppler sonar to image objects with articulated moving components. As an example application for this system, we use it to image gaits of humans and four-legged animals. I will present the micro-Doppler gait signatures of a walking person, a dog and a horse. I will discuss the resolution and range of this micro-Doppler sonar and use experimental results to support the theoretical analyses. In order to reduce the data rate and make the system amenable to wireless sensor networks, I will present a second micro-Doppler sonar that uses bandpass sampling for data acquisition. Speech recognition algorithms are explored for biometric identifications from one's gait, and I will present and compare the classification performance of the two systems. The acoustic micro-Doppler sonar design and biometric identification results are the first in the field as the previous work used either video camera or microwave technology. I will also review bearing estimation algorithms and present results of applying these algorithms for bearing estimation and tracking of moving vehicles. Another major source of the power consumption at each sensor node is the wireless interface. To address the need of low power communications in a wireless sensor network, I will also discuss the design and implementation of ultra wideband transmitters in a three dimensional

  8. Multimodal integration of micro-Doppler sonar and auditory signals for behavior classification with convolutional networks.

    PubMed

    Dura-Bernal, Salvador; Garreau, Guillaume; Georgiou, Julius; Andreou, Andreas G; Denham, Susan L; Wennekers, Thomas

    2013-10-01

    The ability to recognize the behavior of individuals is of great interest in the general field of safety (e.g. building security, crowd control, transport analysis, independent living for the elderly). Here we report a new real-time acoustic system for human action and behavior recognition that integrates passive audio and active micro-Doppler sonar signatures over multiple time scales. The system architecture is based on a six-layer convolutional neural network, trained and evaluated using a dataset of 10 subjects performing seven different behaviors. Probabilistic combination of system output through time for each modality separately yields 94% (passive audio) and 91% (micro-Doppler sonar) correct behavior classification; probabilistic multimodal integration increases classification performance to 98%. This study supports the efficacy of micro-Doppler sonar systems in characterizing human actions, which can then be efficiently classified using ConvNets. It also demonstrates that the integration of multiple sources of acoustic information can significantly improve the system's performance.

  9. Phase calibration of sonar systems using standard targets and dual-frequency transmission pulses.

    PubMed

    Islas-Cital, Alan; Atkins, Philip R; Foo, Kae Y; Picó, Ruben

    2011-10-01

    The phase angle component of the complex frequency response of a sonar system operating near transducer resonance is usually distorted. Interpretation and classification of the received sonar signal benefits from the preservation of waveform fidelity over the full bandwidth. A calibration process that measures the phase response in addition to the amplitude response is thus required. This paper describes an extension to the standard-target calibration method to include phase angle, without affecting the experimental apparatus, by using dual-frequency transmission pulses and frequency-domain data processing. This approach reduces the impact of unknown range and sound speed parameters upon phase calibration accuracy, as target phase is determined from the relationship of the two frequency components instead of relying on a local phase reference. Tungsten carbide spheres of various sizes were used to simultaneously calibrate the amplitude and phase response of an active sonar system in a laboratory tank. Experimental measurements of target phase spectra are in good agreement with values predicted from a theoretical model based upon full-wave analysis, over an operating frequency of 50-125 kHz.

  10. A Mobile Robot Sonar System with Obstacle Avoidance.

    DTIC Science & Technology

    1994-03-01

    vehicle, robot, obstacle avoidance, sonar sensing 102 17. SECURITY CLASSWIFCATION 1S. SECURITY CLASINFICATION I& SECURITY CLASSIFICATION 20. UMITATION...WITH OBSTACLE - AVOIDANCE __ by __ Patrick Gerard Byrne March 1994 Thesis Advisor: Yutaka Kanayama Approved for public release; distribution is...SEOLY(Lae anO r Iff TDT, Master’s Thesis _____________ 4. TITLE AND SUBTITLE L FUMNING NUMBR A Mobile Robot Sonar System With Obstacle Avoidance (U

  11. Computer Model of a High-Resolution Imaging Sonar

    DTIC Science & Technology

    1990-07-01

    This is a very efficient method of obtaining imagcs in near-real-time. These sonars have found wide use in underwater vehicles and submersibles...perceived by an optical camera at the sonar location is generated by the method of range shading. This image serves as a reference for the subsequent efforts...Bhawan New Delhi, 110003 INDIA 10. Dr. V.P. Kodali Adviser Electronics Commission Lok Nayak Bhawan New Delhi, 110003 INDIA 11. Professor A.K. Jain

  12. Beaked Whales Respond to Simulated and Actual Navy Sonar

    PubMed Central

    Tyack, Peter L.; Zimmer, Walter M. X.; Moretti, David; Southall, Brandon L.; Claridge, Diane E.; Durban, John W.; Clark, Christopher W.; D'Amico, Angela; DiMarzio, Nancy; Jarvis, Susan; McCarthy, Elena; Morrissey, Ronald; Ward, Jessica; Boyd, Ian L.

    2011-01-01

    Beaked whales have mass stranded during some naval sonar exercises, but the cause is unknown. They are difficult to sight but can reliably be detected by listening for echolocation clicks produced during deep foraging dives. Listening for these clicks, we documented Blainville's beaked whales, Mesoplodon densirostris, in a naval underwater range where sonars are in regular use near Andros Island, Bahamas. An array of bottom-mounted hydrophones can detect beaked whales when they click anywhere within the range. We used two complementary methods to investigate behavioral responses of beaked whales to sonar: an opportunistic approach that monitored whale responses to multi-day naval exercises involving tactical mid-frequency sonars, and an experimental approach using playbacks of simulated sonar and control sounds to whales tagged with a device that records sound, movement, and orientation. Here we show that in both exposure conditions beaked whales stopped echolocating during deep foraging dives and moved away. During actual sonar exercises, beaked whales were primarily detected near the periphery of the range, on average 16 km away from the sonar transmissions. Once the exercise stopped, beaked whales gradually filled in the center of the range over 2–3 days. A satellite tagged whale moved outside the range during an exercise, returning over 2–3 days post-exercise. The experimental approach used tags to measure acoustic exposure and behavioral reactions of beaked whales to one controlled exposure each of simulated military sonar, killer whale calls, and band-limited noise. The beaked whales reacted to these three sound playbacks at sound pressure levels below 142 dB re 1 µPa by stopping echolocation followed by unusually long and slow ascents from their foraging dives. The combined results indicate similar disruption of foraging behavior and avoidance by beaked whales in the two different contexts, at exposures well below those used by regulators to define

  13. Development of Castor-Oil-Resistant Polyurethane Sonar Encapsulants.

    DTIC Science & Technology

    2014-09-26

    7D-S? 576 DEVELOPMENT OF CASTOR- OIL -RESISTANT POLYURETHANE SONAR 1/1 ENCRPSULANTS(U) NRVAL RESEARCH LAB MASHINGTON DC UNCLSSIFED T MA3URICE ET AL. 30...ACCESSION NO. Washington, DC 23062 64503N I S0219AS (59)0584 i1 TITLE (Include Security Classification) Development of Castor- Oil -Resistant...identify by block number) FIELD GROUP SUB-GROUP Castor oil -- Sonar transducer encapsulants 11 07 - Polyurethane\\ K , 19. ABSTRACT (Continue on reverse if

  14. Beaked whales respond to simulated and actual navy sonar.

    PubMed

    Tyack, Peter L; Zimmer, Walter M X; Moretti, David; Southall, Brandon L; Claridge, Diane E; Durban, John W; Clark, Christopher W; D'Amico, Angela; DiMarzio, Nancy; Jarvis, Susan; McCarthy, Elena; Morrissey, Ronald; Ward, Jessica; Boyd, Ian L

    2011-03-14

    Beaked whales have mass stranded during some naval sonar exercises, but the cause is unknown. They are difficult to sight but can reliably be detected by listening for echolocation clicks produced during deep foraging dives. Listening for these clicks, we documented Blainville's beaked whales, Mesoplodon densirostris, in a naval underwater range where sonars are in regular use near Andros Island, Bahamas. An array of bottom-mounted hydrophones can detect beaked whales when they click anywhere within the range. We used two complementary methods to investigate behavioral responses of beaked whales to sonar: an opportunistic approach that monitored whale responses to multi-day naval exercises involving tactical mid-frequency sonars, and an experimental approach using playbacks of simulated sonar and control sounds to whales tagged with a device that records sound, movement, and orientation. Here we show that in both exposure conditions beaked whales stopped echolocating during deep foraging dives and moved away. During actual sonar exercises, beaked whales were primarily detected near the periphery of the range, on average 16 km away from the sonar transmissions. Once the exercise stopped, beaked whales gradually filled in the center of the range over 2-3 days. A satellite tagged whale moved outside the range during an exercise, returning over 2-3 days post-exercise. The experimental approach used tags to measure acoustic exposure and behavioral reactions of beaked whales to one controlled exposure each of simulated military sonar, killer whale calls, and band-limited noise. The beaked whales reacted to these three sound playbacks at sound pressure levels below 142 dB re 1 µPa by stopping echolocation followed by unusually long and slow ascents from their foraging dives. The combined results indicate similar disruption of foraging behavior and avoidance by beaked whales in the two different contexts, at exposures well below those used by regulators to define

  15. Application of mobile robot localization using sonar

    SciTech Connect

    Byrd, J.S.; Hill, K.H.

    1994-12-31

    A sonar-based mobile robot has been developed for inspection of low-level radioactive waste drums. An algorithm was developed which gives the robot the ability to refence itself to cylindrical objects. The drum-following algorithm has been demonstrated in 4-ft drum aisles at the Mobile Robotics Laboratory at the University of South Carolina. The final version has proven to be robust through extensive long-term navigation tests. Future enhancements will employ a narrow-aisle version of the Nav-master to allow navigation in 3-ft drum aisles. The final version of the inspection robot will include the drum-navigation algorithm as a low-level primitive instruction. The onboard management system will be dedicated to more of the high-level functions, such as planning, now provided by the offboard supervisory system.

  16. Automated change detection for synthetic aperture sonar

    NASA Astrophysics Data System (ADS)

    G-Michael, Tesfaye; Marchand, Bradley; Tucker, J. D.; Sternlicht, Daniel D.; Marston, Timothy M.; Azimi-Sadjadi, Mahmood R.

    2014-05-01

    In this paper, an automated change detection technique is presented that compares new and historical seafloor images created with sidescan synthetic aperture sonar (SAS) for changes occurring over time. The method consists of a four stage process: a coarse navigational alignment; fine-scale co-registration using the scale invariant feature transform (SIFT) algorithm to match features between overlapping images; sub-pixel co-registration to improves phase coherence; and finally, change detection utilizing canonical correlation analysis (CCA). The method was tested using data collected with a high-frequency SAS in a sandy shallow-water environment. By using precise co-registration tools and change detection algorithms, it is shown that the coherent nature of the SAS data can be exploited and utilized in this environment over time scales ranging from hours through several days.

  17. Bistatic Sonar and Quantification of Seafloor Processes

    NASA Astrophysics Data System (ADS)

    McCloghrie, P.; BLONDEL, P.; Pace, N. G.; Heald, G. J.; Brothers, R.

    2001-12-01

    Sonar has proved the best tool for investigation of seafloor processes. Calibrated sonars provide a wealth of quantitative information unattainable through other means, but are limited to backscattering geometries, where the acoustic source and receiver are on the same platform. Recent developments in acoustic theory and design have shown the advantage of bistatic instruments, where the source and receiver(s) are physically decoupled and can be anywhere in the water column. Although there are many theoretical studies of bistatic scattering, their applicability is limited by the very low number of actual experiments. Using the large tank facilities at the University of Bath, we are currently investigating the bistatic scattering from several realistic types of seabeds and different morphologies, at high frequency (250 kHz). These studies are used in conjunction with state-of-the-art acoustic models (Blondel et al., 2001), and compared with data from complementary sea trials (Pace et al., in prep.). The results show the huge potential of bistatic systems for accurate and detailed mapping of seafloor structures and their topography. We also demonstrate how the relative contributions of surface and volume processes to acoustic scattering change with the imaging geometry, and how this can be used to maximise the information gained during mapping. Versatile and efficient, bistatic systems can be deployed from surface vessels, ROVs or AUVs. These new tools can be used for Rapid Environmental Assessment, to study sediment transport and deposition, and to access the detailed morphology of the seabed and the near sub-surface. They can in particular be used for the investigation of the small-scale structure of sand ridges and ripples, the distribution of tidal or glacial deposits on the seabed, and the quantification of multi-scale surface roughness in sedimentary and non-sedimentary terrains alike. Crown Copyright 2001 DERA. Published with the permission of the Defence

  18. BatSLAM: Simultaneous localization and mapping using biomimetic sonar.

    PubMed

    Steckel, Jan; Peremans, Herbert

    2013-01-01

    We propose to combine a biomimetic navigation model which solves a simultaneous localization and mapping task with a biomimetic sonar mounted on a mobile robot to address two related questions. First, can robotic sonar sensing lead to intelligent interactions with complex environments? Second, can we model sonar based spatial orientation and the construction of spatial maps by bats? To address these questions we adapt the mapping module of RatSLAM, a previously published navigation system based on computational models of the rodent hippocampus. We analyze the performance of the proposed robotic implementation operating in the real world. We conclude that the biomimetic navigation model operating on the information from the biomimetic sonar allows an autonomous agent to map unmodified (office) environments efficiently and consistently. Furthermore, these results also show that successful navigation does not require the readings of the biomimetic sonar to be interpreted in terms of individual objects/landmarks in the environment. We argue that the system has applications in robotics as well as in the field of biology as a simple, first order, model for sonar based spatial orientation and map building.

  19. Statistically normalized coherent change detection for synthetic aperture sonar imagery

    NASA Astrophysics Data System (ADS)

    G-Michael, Tesfaye; Tucker, J. D.; Roberts, Rodney G.

    2016-05-01

    Coherent Change Detection (CCD) is a process of highlighting an area of activity in scenes (seafloor) under survey and generated from pairs of synthetic aperture sonar (SAS) images of approximately the same location observed at two different time instances. The problem of CCD and subsequent anomaly feature extraction/detection is complicated due to several factors such as the presence of random speckle pattern in the images, changing environmental conditions, and platform instabilities. These complications make the detection of weak target activities even more difficult. Typically, the degree of similarity between two images measured at each pixel locations is the coherence between the complex pixel values in the two images. Higher coherence indicates little change in the scene represented by the pixel and lower coherence indicates change activity in the scene. Such coherence estimation scheme based on the pixel intensity correlation is an ad-hoc procedure where the effectiveness of the change detection is determined by the choice of threshold which can lead to high false alarm rates. In this paper, we propose a novel approach for anomalous change pattern detection using the statistical normalized coherence and multi-pass coherent processing. This method may be used to mitigate shadows by reducing the false alarms resulting in the coherent map due to speckles and shadows. Test results of the proposed methods on a data set of SAS images will be presented, illustrating the effectiveness of the normalized coherence in terms statistics from multi-pass survey of the same scene.

  20. "Gas and fat embolic syndrome" involving a mass stranding of beaked whales (family Ziphiidae) exposed to anthropogenic sonar signals.

    PubMed

    Fernández, A; Edwards, J F; Rodríguez, F; Espinosa de los Monteros, A; Herráez, P; Castro, P; Jaber, J R; Martín, V; Arbelo, M

    2005-07-01

    A study of the lesions of beaked whales (BWs) in a recent mass stranding in the Canary Islands following naval exercises provides a possible explanation of the relationship between anthropogenic, acoustic (sonar) activities and the stranding and death of marine mammals. Fourteen BWs were stranded in the Canary Islands close to the site of an international naval exercise (Neo-Tapon 2002) held on 24 September 2002. Strandings began about 4 hours after the onset of midfrequency sonar activity. Eight Cuvier's BWs (Ziphius cavirostris), one Blainville's BW (Mesoplodon densirostris), and one Gervais' BW (Mesoplodon europaeus) were examined postmortem and studied histopathologically. No inflammatory or neoplastic processes were noted, and no pathogens were identified. Macroscopically, whales had severe, diffuse congestion and hemorrhage, especially around the acoustic jaw fat, ears, brain, and kidneys. Gas bubble-associated lesions and fat embolism were observed in the vessels and parenchyma of vital organs. In vivo bubble formation associated with sonar exposure that may have been exacerbated by modified diving behavior caused nitrogen supersaturation above a threshold value normally tolerated by the tissues (as occurs in decompression sickness). Alternatively, the effect that sonar has on tissues that have been supersaturated with nitrogen gas could be such that it lowers the threshold for the expansion of in vivo bubble precursors (gas nuclei). Exclusively or in combination, these mechanisms may enhance and maintain bubble growth or initiate embolism. Severely injured whales died or became stranded and died due to cardiovascular collapse during beaching. The present study demonstrates a new pathologic entity in cetaceans. The syndrome is apparently induced by exposure to mid-frequency sonar signals and particularly affects deep, long-duration, repetitive-diving species like BWs.

  1. Implementation and testing of a Deep Water Correlation Velocity Sonar

    SciTech Connect

    Dickey, F.R.; Bookheimer, W.C.; Rhoades, K.W.

    1983-05-01

    The paper describes a new sonar designated the Magnavox MX 810 Deep Water Correlation Sonar which is under development by the General Electric Company and the Magnavox Advanced Products and Systems Company. The sonar measures ship's velocity relative to the bottom but instead of using the conventional doppler effect, it uses the correlation method described by Dickey and Edward in 1978. In this method, the narrow beams required for doppler are not needed and a low frequency that penetrates to the bottom in deep water is used. The sonar was designed with the constraint that it use a transducer that mounts through a single 12 inch gate valve. Most offshore geophysical surveys at present make use of an integrated navigation system with bottom referenced velocity input from a doppler sonar which, because of limitations on the sonar bottomtracking range, has difficulty in areas where the water depth is greater than about 500 meters. The MX 810 provides bottom tracking in regions of much greater water depth. It also may be applied as an aid in continuous positioning of a vessel over a fixed location. It also should prove useful as a more general navigation aid. The sonar is undergoing a series of tests using Magnavox's facilities for the purpose of verifying the performance and obtaining data to support and quantify planned improvements in both software and hardware. A prototype transducer of only 5 watts power output was used, but in spite of this low power, successful operation to depths of 1900 meters was obtained. Extrapolation to system parameters to be implemented in production models predicts operation to depths of 5000 meters.

  2. Performance and Preference on a Sonar Detection Task under Various Colors of Ambient Illumination

    DTIC Science & Technology

    1984-05-17

    fine acuity , color vision, and dark adaptation. Due to the additional advantages of subdued white illumination, it is recommended for use in sonar...sonar systems of the increase in the number of provided primarily auditory signals visual displays. The change to for the cperator to use in the blue, in...which tried blue was so much more important than the sleeves over the light bulbs in the visual , lighting in the sonar shack sonar control room and

  3. Modeling interface roughness scattering in a layered seabed for normal-incident chirp sonar signals.

    PubMed

    Tang, Dajun; Hefner, Brian T

    2012-04-01

    Downward looking sonar, such as the chirp sonar, is widely used as a sediment survey tool in shallow water environments. Inversion of geo-acoustic parameters from such sonar data precedes the availability of forward models. An exact numerical model is developed to initiate the simulation of the acoustic field produced by such a sonar in the presence of multiple rough interfaces. The sediment layers are assumed to be fluid layers with non-intercepting rough interfaces.

  4. A Computer Simulation Study of Station Keeping by an Autonomous Submersible Using Bottom-Tracking Sonar

    DTIC Science & Technology

    1988-06-01

    63 Figure 5.1 "Lock On" Illustration .................................................................... 68 Figure 5.2 Depth Below AUV / Sonar Range... AUV sonar scan mechanism in Earth coordinates. Given Equation (3.2), from Figure 3.8, the transformation from AUV coordinates to beam tip (end effector...0Cells inside circle = accessible cells =pi* r2 15 2 * pi = 706 accessible cells Depth Below AUV / Sonar Range Sonar Range 14.1 cell radius i RI 150 m depth

  5. Mitigation Modelling of the Leeuwin Class Hydrographic Sonars in Shoalwater Bay

    DTIC Science & Technology

    2009-12-01

    The welfare of dolphins and dugongs is the main concern in Shoalwater Bay in reference to hydrographic sonar frequencies. Modelling therefore...considered all sonars capable of radiating signals within the auditory frequency range of dolphins, 1 to 150 kHz, and dugongs , 1 to 8 kHz. Sonar operations...at frequencies above 200 kHz were not considered since the effects on dolphins and dugongs were assumed inconsequential. The sonar with the lowest

  6. Sodar - PNNL Scintec MFAS, Oregon Raceway Park - Raw Data

    SciTech Connect

    Pekour, Mikhail

    2016-10-25

    Provide measurements of wind speed and direction up to 400 m AGL (max). The data are stored in 2 forms: ASCII and raw (binary). ASCII files contain averaged data (currently -- 15 min time step and 10 m range gate); raw files could be reprocessed with the sodar software (APRun by Scintec) to produce ASCII files with different time and/or height averaging settings (highest resolution is approx. 90 sec and 10 m).

  7. Sonar-induced temporary hearing loss in dolphins.

    PubMed

    Mooney, T Aran; Nachtigall, Paul E; Vlachos, Stephanie

    2009-08-23

    There is increasing concern that human-produced ocean noise is adversely affecting marine mammals, as several recent cetacean mass strandings may have been caused by animals' interactions with naval 'mid-frequency' sonar. However, it has yet to be empirically demonstrated how sonar could induce these strandings or cause physiological effects. In controlled experimental studies, we show that mid-frequency sonar can induce temporary hearing loss in a bottlenose dolphin (Tursiops truncatus). Mild-behavioural alterations were also associated with the exposures. The auditory effects were induced only by repeated exposures to intense sonar pings with total sound exposure levels of 214 dB re: 1 microPa(2) s. Data support an increasing energy model to predict temporary noise-induced hearing loss and indicate that odontocete noise exposure effects bear trends similar to terrestrial mammals. Thus, sonar can induce physiological and behavioural effects in at least one species of odontocete; however, exposures must be of prolonged, high sound exposures levels to generate these effects.

  8. Validating side scan sonar as a fish survey tool

    NASA Astrophysics Data System (ADS)

    Bollinger, Michael A.

    Hydroacoustic methods can be used to answer a variety of questions regarding fish populations and behavior. In this study, side scan sonar methodology was developed to quantify abundance and biomass and compared to established visual observation methods on SCUBA over artificial reef structures in the western Gulf of Mexico. Side scan sonar methods were equivalent to SCUBA surveys for measuring fish abundance over the same reef areas, however, abundances were significantly higher when the larger area sampled by side scan was utilized. Side scan sonar methods were also more time efficient than SCUBA, ROV and long line fishing methods (66.7%, 33.3%, 25.9% respectively). In addition, side scan methods allowed biomass and fish size class categories to be estimated over reef sites. Side scan methods allowed five reef sites to be surveyed in one day, demonstrating the capability for macro scale comparisons of fish abundance, biomass and behavior among sites.

  9. Sonar surveys used in gas-storage cavern analysis

    SciTech Connect

    Crossley, N.G.

    1998-05-04

    Natural-gas storage cavern internal configuration, inspection information, and cavern integrity data can be obtained during high-pressure operations with specialized gas-sonar survey logging techniques. TransGas Ltd., Regina, Sask., has successfully performed these operations on several of its deepest and highest pressurized caverns. The data can determine gas-in-place inventory and assess changes in spatial volumes. These changes can result from cavern creep, shrinkage, or closure or from various downhole abnormalities such as fluid infill or collapse of the sidewall or roof. The paper discusses conventional surveys with sonar, running surveys in pressurized caverns, accuracy of the sonar survey, initial development of Cavern 5, a roof fall, Cavern 4 development, and a damaged string.

  10. Quantification of Diffuse Hydrothermal Flows Using Multibeam Sonar

    NASA Astrophysics Data System (ADS)

    Ivakin, A. N.; Jackson, D. R.; Bemis, K. G.; Xu, G.

    2014-12-01

    The Cabled Observatory Vent Imaging Sonar (COVIS) deployed at the Main Endeavour node of the NEPTUNE Canada observatory has provided acoustic time series extending over 2 years. This includes 3D images of plume scattering strength and Doppler velocity measurements as well as 2D images showing regions of diffuse flow. The diffuse-flow images display the level of decorrelation between sonar echos with transmissions separated by 0.2 s. The present work aims to provide further information on the strength of diffuse flows. Two approaches are used: Measurement of the dependence of decorrelation on lag and measurement of phase shift of sonar echos, with lags in 3-hour increments up to several days. The phase shifts and decorrelation are linked to variations of temperature above the seabed, which allows quantification of those variations, their magnitudes, spatial and temporal scales, and energy spectra. These techniques are illustrated using COVIS data obtained near the Grotto vent complex.

  11. Ecological echoes observed by moving biomimetic sonar characterize objects

    NASA Astrophysics Data System (ADS)

    Kuc, Roman

    2001-05-01

    This paper examines echoes from in situ foliage, similar to those observed by flying bats. A moving sonar converts echoes into spike sequences and applies neural-computational methods to estimate passing range and travel speed. Retro-reflectors and favorably oriented planar patches generate strong echoes (SEs), identified by spike firing rate. Linear sonar trajectories cause SEs to form hyperbolic patterns, termed glints, specified by passing range and travel speed. Passing-range specific detectors compare successive SE times with values in a table and tally coincidences. A glint terminates after a sufficient number of coincidences are tallied and two consecutive mismatches occur in the maximum-count detector. SE arrival jitter necessitates a coincidence window. Short windows identify individual glints while long windows generalize extended objects. SEs from distant objects exhibit almost constant incremental delays, used to estimate sonar travel speed, necessary for robust glint detection. Passing-range estimates may explain how bats can fly through small openings without collision.

  12. Quantifying methane flux from lake sediments using multibeam sonar

    NASA Astrophysics Data System (ADS)

    Scandella, B.; Urban, P.; Delwiche, K.; Greinert, J.; Hemond, H.; Ruppel, C. D.; Juanes, R.

    2013-12-01

    Methane is a potent greenhouse gas, and the production and emission of methane from sediments in wetlands, lakes and rivers both contributes to and may be exacerbated by climate change. In some of these shallow-water settings, methane fluxes may be largely controlled by episodic venting that can be triggered by drops in hydrostatic pressure. Even with better constraints on the mechanisms for gas release, quantifying these fluxes has remained a challenge due to rapid spatiotemporal changes in the patterns of bubble emissions from the sediments. The research presented here uses a fixed-location Imagenex DeltaT 837B multibeam sonar to estimate methane-venting fluxes from organic-rich lake sediments over a large area (~400 m2) and over a multi-season deployment period with unprecedented spatial and temporal resolution. Simpler, single-beam sonar systems have been used in the past to estimate bubble fluxes in a variety of settings. Here we extend this methodology to a multibeam system by means of: (1) detailed calibration of the sonar signal against imposed bubble streams, and (2) validation against an in situ independent record of gas flux captured by overlying bubble traps. The calibrated sonar signals then yield estimates of the methane flux with high spatial resolution (~1 m) and temporal frequency (6 Hz) from a portion of the deepwater basin of Upper Mystic Lake, MA, USA, a temperate eutrophic kettle lake. These results in turn inform mathematical models of methane transport and release from the sediments, which reproduce with high fidelity the ebullitive response to hydrostatic pressure variations. In addition, the detailed information about spatial variability of methane flux derived from sonar records is used to estimate the uncertainty associated with upscaling flux measurements from bubble traps to the scale of the sonar observation area. Taken together, these multibeam sonar measurements and analysis provide a novel quantitative approach for the assessment of

  13. SONAR Discovers RNA-Binding Proteins from Analysis of Large-Scale Protein-Protein Interactomes.

    PubMed

    Brannan, Kristopher W; Jin, Wenhao; Huelga, Stephanie C; Banks, Charles A S; Gilmore, Joshua M; Florens, Laurence; Washburn, Michael P; Van Nostrand, Eric L; Pratt, Gabriel A; Schwinn, Marie K; Daniels, Danette L; Yeo, Gene W

    2016-10-20

    RNA metabolism is controlled by an expanding, yet incomplete, catalog of RNA-binding proteins (RBPs), many of which lack characterized RNA binding domains. Approaches to expand the RBP repertoire to discover non-canonical RBPs are currently needed. Here, HaloTag fusion pull down of 12 nuclear and cytoplasmic RBPs followed by quantitative mass spectrometry (MS) demonstrates that proteins interacting with multiple RBPs in an RNA-dependent manner are enriched for RBPs. This motivated SONAR, a computational approach that predicts RNA binding activity by analyzing large-scale affinity precipitation-MS protein-protein interactomes. Without relying on sequence or structure information, SONAR identifies 1,923 human, 489 fly, and 745 yeast RBPs, including over 100 human candidate RBPs that contain zinc finger domains. Enhanced CLIP confirms RNA binding activity and identifies transcriptome-wide RNA binding sites for SONAR-predicted RBPs, revealing unexpected RNA binding activity for disease-relevant proteins and DNA binding proteins.

  14. GM-PHD filter multitarget tracking in sonar images

    NASA Astrophysics Data System (ADS)

    Clark, Daniel; Vo, Ba-Ngu; Bell, Judith

    2006-05-01

    The Gaussian Mixure Probability Hypothesis Density (GM-PHD) Multi-target Tracker was developed as an extension to the GM-PHD filter to provide track continuity. The algorithm is demonstrated on forward-looking sonar data with clutter and is compared with the results from the Particle PHD filter.

  15. Wreck finding and classifying with a sonar filter

    NASA Astrophysics Data System (ADS)

    Agehed, Kenneth I.; Padgett, Mary Lou; Becanovic, Vlatko; Bornich, C.; Eide, Age J.; Engman, Per; Globoden, O.; Lindblad, Thomas; Lodgberg, K.; Waldemark, Karina E.

    1999-03-01

    Sonar detection and classification of sunken wrecks and other objects is of keen interest to many. This paper describes the use of neural networks (NN) for locating, classifying and determining the alignment of objects on a lakebed in Sweden. A complex program for data preprocessing and visualization was developed. Part of this program, The Sonar Viewer, facilitates training and testing of the NN using (1) the MATLAB Neural Networks Toolbox for multilayer perceptrons with backpropagation (BP) and (2) the neural network O-Algorithm (OA) developed by Age Eide and Thomas Lindblad. Comparison of the performance of the two neural networks approaches indicates that, for this data BP generalizes better than OA, but use of OA eliminates the need for training on non-target (lake bed) images. The OA algorithm does not work well with the smaller ships. Increasing the resolution to counteract this problem would slow down processing and require interpolation to suggest data values between the actual sonar measurements. In general, good results were obtained for recognizing large wrecks and determining their alignment. The programs developed a useful tool for further study of sonar signals in many environments. Recent developments in pulse coupled neural networks techniques provide an opportunity to extend the use in real-world applications where experimental data is difficult, expensive or time consuming to obtain.

  16. A Rolling Line Source for a Seismic Sonar

    DTIC Science & Technology

    2002-06-01

    first used for bottom sounding and echolocation in the early 20th century by the French scientist Paul Langevin, a friend of the famous chemist Madam ...Marie Curie . Now acoustic sonars are well developed, and are an integral part of every warship, worldwide. Seismic interface waves, such as

  17. Hulu Sungai Perak Bed Sediment Mapping Using Underwater Acoustic Sonar

    NASA Astrophysics Data System (ADS)

    Arriafdi, N.; Zainon, O.; Din, U.; Rasid, A. W.; Mat Amin, Z.; Othman, R.; Mardi, A. S.; Mahmud, R.; Sulaiman, N.

    2016-09-01

    Development in acoustic survey techniques in particular side scan sonar have revolutionized the way we are able to image, map and understand the riverbed environment. It is now cost effective to image large areas of the riverbed using these techniques and the backscatter image created from surveys provides base line data from which thematic maps of the riverbed environment including maps of morphological geology, can be derived when interpreted in conjunction with in situ sampling data. This article focuses on investigation characteristics of sediments and correlation of side scan backscatter image with signal strength. The interpretation of acoustic backscatter rely on experienced interpretation by eye of grey scale images produced from the data. A 990F Starfish Side Scan Sonar was used to collect and develop a series of sonar images along 6 km of Hulu Sungai Perak. Background sediments could be delineated accurately and the image textures could be linked to the actual river floor appearance through grab sampling. A major difference was found in the acoustic returns from the two research area studies: the upstream area shows much rougher textures. This is due to an actual differences in riverbed roughness, caused by a difference in bottom currents and sediment dynamics in the two areas. The highest backscatter correlates with coarsest and roughness sediment. Result suggest that image based backscatter classification shows considerable promise for interpretation of side scan sonar data for the production of geological maps.

  18. Enhanced Sidescan-Sonar Imagery Offshore of Southeastern Massachusetts

    USGS Publications Warehouse

    Poppe, Lawrence J.; McMullen, Kate Y.; Williams, S. Jeffress; Ackerman, Seth D.; Glomb, K.A.; Forfinski, N.A.

    2008-01-01

    The U.S. Geological Survey (USGS), National Oceanic and Atmospheric Administration (NOAA), and Massachusetts Office of Coastal Zone Management (CZM) have been working cooperatively to map and study the coastal sea floor. The sidescan-sonar imagery collected during NOAA hydrographic surveys has been included as part of these studies. However, the original sonar imagery contains tonal artifacts from environmental noise (for example, sea state), equipment settings (for example, power and gain changes), and processing (for example, inaccurate cross-track and line-to-line normalization), which impart a quilt-like patchwork appearance to the mosaics. These artifacts can obscure the normalized backscatter properties of the sea floor. To address this issue, sidescan-sonar imagery from surveys H11076 and H11079 offshore of southeastern Massachusetts was enhanced by matching backscatter tones of adjacent sidescan-sonar lines. These mosaics provide continuous grayscale perspectives of the backscatter, more accurately reveal the sea-floor geologic trends, and minimize the environment-, acquisition-, and processing-related noise.

  19. Estimated Tissue and Blood N(2) Levels and Risk of Decompression Sickness in Deep-, Intermediate-, and Shallow-Diving Toothed Whales during Exposure to Naval Sonar.

    PubMed

    Kvadsheim, P H; Miller, P J O; Tyack, P L; Sivle, L D; Lam, F P A; Fahlman, A

    2012-01-01

    Naval sonar has been accused of causing whale stranding by a mechanism which increases formation of tissue N(2) gas bubbles. Increased tissue and blood N(2) levels, and thereby increased risk of decompression sickness (DCS), is thought to result from changes in behavior or physiological responses during diving. Previous theoretical studies have used hypothetical sonar-induced changes in both behavior and physiology to model blood and tissue N(2) tension [Formula: see text], but this is the first attempt to estimate the changes during actual behavioral responses to sonar. We used an existing mathematical model to estimate blood and tissue N(2) tension [Formula: see text] from dive data recorded from sperm, killer, long-finned pilot, Blainville's beaked, and Cuvier's beaked whales before and during exposure to Low- (1-2 kHz) and Mid- (2-7 kHz) frequency active sonar. Our objectives were: (1) to determine if differences in dive behavior affects risk of bubble formation, and if (2) behavioral- or (3) physiological responses to sonar are plausible risk factors. Our results suggest that all species have natural high N(2) levels, with deep diving generally resulting in higher end-dive [Formula: see text] as compared with shallow diving. Sonar exposure caused some changes in dive behavior in both killer whales, pilot whales and beaked whales, but this did not lead to any increased risk of DCS. However, in three of eight exposure session with sperm whales, the animal changed to shallower diving, and in all these cases this seem to result in an increased risk of DCS, although risk was still within the normal risk range of this species. When a hypothetical removal of the normal dive response (bradycardia and peripheral vasoconstriction), was added to the behavioral response during model simulations, this led to an increased variance in the estimated end-dive N(2) levels, but no consistent change of risk. In conclusion, we cannot rule out the possibility that a combination

  20. Estimated Tissue and Blood N2 Levels and Risk of Decompression Sickness in Deep-, Intermediate-, and Shallow-Diving Toothed Whales during Exposure to Naval Sonar

    PubMed Central

    Kvadsheim, P. H.; Miller, P. J. O.; Tyack, P. L.; Sivle, L. D.; Lam, F. P. A.; Fahlman, A.

    2012-01-01

    Naval sonar has been accused of causing whale stranding by a mechanism which increases formation of tissue N2 gas bubbles. Increased tissue and blood N2 levels, and thereby increased risk of decompression sickness (DCS), is thought to result from changes in behavior or physiological responses during diving. Previous theoretical studies have used hypothetical sonar-induced changes in both behavior and physiology to model blood and tissue N2 tension PN2, but this is the first attempt to estimate the changes during actual behavioral responses to sonar. We used an existing mathematical model to estimate blood and tissue N2 tension PN2 from dive data recorded from sperm, killer, long-finned pilot, Blainville’s beaked, and Cuvier’s beaked whales before and during exposure to Low- (1–2 kHz) and Mid- (2–7 kHz) frequency active sonar. Our objectives were: (1) to determine if differences in dive behavior affects risk of bubble formation, and if (2) behavioral- or (3) physiological responses to sonar are plausible risk factors. Our results suggest that all species have natural high N2 levels, with deep diving generally resulting in higher end-dive PN2 as compared with shallow diving. Sonar exposure caused some changes in dive behavior in both killer whales, pilot whales and beaked whales, but this did not lead to any increased risk of DCS. However, in three of eight exposure session with sperm whales, the animal changed to shallower diving, and in all these cases this seem to result in an increased risk of DCS, although risk was still within the normal risk range of this species. When a hypothetical removal of the normal dive response (bradycardia and peripheral vasoconstriction), was added to the behavioral response during model simulations, this led to an increased variance in the estimated end-dive N2 levels, but no consistent change of risk. In conclusion, we cannot rule out the possibility that a combination of behavioral and physiological responses to sonar

  1. Reliability of fish size estimates obtained from multibeam imaging sonar

    USGS Publications Warehouse

    Hightower, Joseph E.; Magowan, Kevin J.; Brown, Lori M.; Fox, Dewayne A.

    2013-01-01

    Multibeam imaging sonars have considerable potential for use in fisheries surveys because the video-like images are easy to interpret, and they contain information about fish size, shape, and swimming behavior, as well as characteristics of occupied habitats. We examined images obtained using a dual-frequency identification sonar (DIDSON) multibeam sonar for Atlantic sturgeon Acipenser oxyrinchus oxyrinchus, striped bass Morone saxatilis, white perch M. americana, and channel catfish Ictalurus punctatus of known size (20–141 cm) to determine the reliability of length estimates. For ranges up to 11 m, percent measurement error (sonar estimate – total length)/total length × 100 varied by species but was not related to the fish's range or aspect angle (orientation relative to the sonar beam). Least-square mean percent error was significantly different from 0.0 for Atlantic sturgeon (x̄  =  −8.34, SE  =  2.39) and white perch (x̄  = 14.48, SE  =  3.99) but not striped bass (x̄  =  3.71, SE  =  2.58) or channel catfish (x̄  = 3.97, SE  =  5.16). Underestimating lengths of Atlantic sturgeon may be due to difficulty in detecting the snout or the longer dorsal lobe of the heterocercal tail. White perch was the smallest species tested, and it had the largest percent measurement errors (both positive and negative) and the lowest percentage of images classified as good or acceptable. Automated length estimates for the four species using Echoview software varied with position in the view-field. Estimates tended to be low at more extreme azimuthal angles (fish's angle off-axis within the view-field), but mean and maximum estimates were highly correlated with total length. Software estimates also were biased by fish images partially outside the view-field and when acoustic crosstalk occurred (when a fish perpendicular to the sonar and at relatively close range is detected in the side lobes of adjacent beams). These sources of

  2. 3D Chirp Sonar Images on Fluid Migration Pathways and Their Implications on Seafloor Stability East of the Fangliao Submarine Canyon Offshore SW Taiwan

    NASA Astrophysics Data System (ADS)

    Lu, Y. W.; Liu, C. S.; Su, C. C.; Hsu, H. H.; Chen, Y. H.

    2015-12-01

    This study utilizes both chirp sonar images and coring results to investigate the unstable seafloor strata east of the Fangliao Submarine Canyon offshore southwestern Taiwan. We have constructed 3D chirp sonar images from a densely surveyed block to trace the attitude of an acoustic transparent layer and features caused by fluid activities. Based on the distribution of this transparent layer and fluid-related features, we suggest that this transparent layer forms a pathway for fluid migration which induces fluid-related characters such as acoustic blanking and fluid chimneys in the 3D chirp sonar images. Cored seafloor samples are used in this study to investigate the sediment compositions. The 210Pb activity profiles of the cores show oscillating and unsteady values at about 20~25 cm from core top. The bulk densities of the core samples in the same section (about 20~25 cm from core top) give values lower than those at deeper parts of the cores. These results indicate that the water content is much higher in the shallow sediments than in the deeper strata. From core sample analyses, we deduce that the local sediments are disturbed by liquefaction. From the analyses of 3D chirp sonar images and core data, we suggest that the seafloor east of the Fangliao Submarine Canyon is in an unstable condition, if disturbed by earthquakes, submarine landslides and gravity flows could be easily triggered and cause some geohazards, like breaking submarine cables during the 2006 Pingtung earthquake event.

  3. Big brown bats (Eptesicus fuscus) reveal diverse strategies for sonar target tracking in clutter.

    PubMed

    Mao, Beatrice; Aytekin, Murat; Wilkinson, Gerald S; Moss, Cynthia F

    2016-09-01

    Bats actively adjust the acoustic features of their sonar calls to control echo information specific to a given task and environment. A previous study investigated how bats adapted their echolocation behavior when tracking a moving target in the presence of a stationary distracter at different distances and angular offsets. The use of only one distracter, however, left open the possibility that a bat could reduce the interference of the distracter by turning its head. Here, bats tracked a moving target in the presence of one or two symmetrically placed distracters to investigate adaptive echolocation behavior in a situation where vocalizing off-axis would result in increased interference from distracter echoes. Both bats reduced bandwidth and duration but increased sweep rate in more challenging distracter conditions, and surprisingly, made more head turns in the two-distracter condition compared to one, but only when distracters were placed at large angular offsets. However, for most variables examined, subjects showed distinct strategies to reduce clutter interference, either by (1) changing spectral or temporal features of their calls, or (2) producing large numbers of sonar sound groups and consistent head-turning behavior. The results suggest that individual bats can use different strategies for target tracking in cluttered environments.

  4. Acoustic and foraging behavior of a Baird's beaked whale, Berardius bairdii, exposed to simulated sonar.

    PubMed

    Stimpert, A K; DeRuiter, S L; Southall, B L; Moretti, D J; Falcone, E A; Goldbogen, J A; Friedlaender, A; Schorr, G S; Calambokidis, J

    2014-11-13

    Beaked whales are hypothesized to be particularly sensitive to anthropogenic noise, based on previous strandings and limited experimental and observational data. However, few species have been studied in detail. We describe the underwater behavior of a Baird's beaked whale (Berardius bairdii) from the first deployment of a multi-sensor acoustic tag on this species. The animal exhibited shallow (23 ± 15 m max depth), intermediate (324 ± 49 m), and deep (1138 ± 243 m) dives. Echolocation clicks were produced with a mean inter-click interval of approximately 300 ms and peak frequency of 25 kHz. Two deep dives included presumed foraging behavior, with echolocation pulsed sounds (presumed prey capture attempts) associated with increased maneuvering, and sustained inverted swimming during the bottom phase of the dive. A controlled exposure to simulated mid-frequency active sonar (3.5-4 kHz) was conducted 4 hours after tag deployment, and within 3 minutes of exposure onset, the tagged whale increased swim speed and body movement, and continued to show unusual dive behavior for each of its next three dives, one of each type. These are the first data on the acoustic foraging behavior in this largest beaked whale species, and the first experimental demonstration of a response to simulated sonar.

  5. Acoustic and foraging behavior of a Baird's beaked whale, Berardius bairdii, exposed to simulated sonar

    PubMed Central

    Stimpert, A. K.; DeRuiter, S. L.; Southall, B. L.; Moretti, D. J.; Falcone, E. A.; Goldbogen, J. A.; Friedlaender, A.; Schorr, G. S.; Calambokidis, J.

    2014-01-01

    Beaked whales are hypothesized to be particularly sensitive to anthropogenic noise, based on previous strandings and limited experimental and observational data. However, few species have been studied in detail. We describe the underwater behavior of a Baird's beaked whale (Berardius bairdii) from the first deployment of a multi-sensor acoustic tag on this species. The animal exhibited shallow (23 ± 15 m max depth), intermediate (324 ± 49 m), and deep (1138 ± 243 m) dives. Echolocation clicks were produced with a mean inter-click interval of approximately 300 ms and peak frequency of 25 kHz. Two deep dives included presumed foraging behavior, with echolocation pulsed sounds (presumed prey capture attempts) associated with increased maneuvering, and sustained inverted swimming during the bottom phase of the dive. A controlled exposure to simulated mid-frequency active sonar (3.5–4 kHz) was conducted 4 hours after tag deployment, and within 3 minutes of exposure onset, the tagged whale increased swim speed and body movement, and continued to show unusual dive behavior for each of its next three dives, one of each type. These are the first data on the acoustic foraging behavior in this largest beaked whale species, and the first experimental demonstration of a response to simulated sonar. PMID:25391309

  6. Synthetic Aperture Sonar Low Frequency vs. High Frequency Automatic Contact Generation

    DTIC Science & Technology

    2010-06-01

    resurveyed the harbor with both sidescan sonar (on REMUS) and SAS (on the SSAM AUV) provided by NAVSEA Costal Systems Command. NOMWC, NAVOCEANO and...Synthetic Aperture Sonar Low Frequency vs. High Frequency Automatic Contact Generation J. R. Dubberley and M. L. Gendron Naval Research...Laboratory Code 7440.1 Building 1005 Stennis Space Center, MS 39529 USA Abstract- Synthetic Aperture Sonar (SAS) bottom mapping sensors are on the

  7. Frequency Domain Beamformer for a 3-D Sediment Volume Imaging Synthetic Aperture Sonar

    DTIC Science & Technology

    2010-06-01

    Frequency Domain Beamformer for a 3-D Sediment Volume Imaging Synthetic Aperture Sonar Jonathan R. Pearson Magoon,a Matthew A. Nelson,a Daniel D...synthetic aperture sonars (SAS). The beamformer, designed for systems with receiver arrays oriented transverse to the vehicle, performs standard delay and...volume imaging synthetic aperture sonars (SAS). The beamformer is designed for systems with receiver arrays oriented transverse to the vehicle such

  8. Technology Infusion of CodeSonar into the Space Network Ground Segment

    NASA Technical Reports Server (NTRS)

    Benson, Markland J.

    2009-01-01

    This slide presentation reviews the applicability of CodeSonar to the Space Network software. CodeSonar is a commercial off the shelf system that analyzes programs written in C, C++ or Ada for defects in the code. Software engineers use CodeSonar results as an input to the existing source code inspection process. The study is focused on large scale software developed using formal processes. The systems studied are mission critical in nature but some use commodity computer systems.

  9. Bedform Parameterization and Object Detection from Sonar Data- Application of Finger Print Algorithms

    DTIC Science & Technology

    2012-09-30

    areas with dynamic ripple bedforms and manmade structures. Our approach is to gather (1) the optical and acoustic backscatter properties of surface...sediment layers from an autonomous underwater platform and from surface vessel multibeam echosounder sonar, (2) the small scale (sub-meter) bathymetry...outputs from the finger print code (Figure 1) for use in a variety of sonar image formats (i.e. side-scan mosaic, rotary sonar images, multibeam

  10. Assessment of Marine Mammal Impact Zones for Use of Military Sonar in the Baltic Sea.

    PubMed

    Andersson, Mathias H; Johansson, Torbjörn

    2016-01-01

    Military sonars are known to have caused cetaceans to strand. Navies in shallow seas use different frequencies and sonar pulses, commonly frequencies between 25 and 100 kHz, compared with most studied NATO sonar systems that have been evaluated for their environmental impact. These frequencies match the frequencies of best hearing in the harbor porpoises and seals resident in the Baltic Sea. This study uses published temporary and permanent threshold shifts, measured behavioral response thresholds, technical specifications of a sonar system, and environmental parameters affecting sound propagation common for the Baltic Sea to estimate the impact zones for harbor porpoises and seals.

  11. Algorithms for the Fusion of Two Sets of (Sonar) Data

    DTIC Science & Technology

    2006-12-01

    dB ifDT= 10. ONGERUBRICEERD ONGERUBRICEERD I TNO reportI TNO-DV 2006 A518 33/51 S........ .... -@"Z sonar 2 -> sonar 1so rI- 0.9 ... theory 0.8. 0.7...pings. ONGERUBRICEERD ONGERUBRICEERD I TNO reportI TNO-DV 2006 A518 37/51 •+• -0- Fade. - false SFire.- true 0.16 -=- True-fiji.-0= Tiuesi- trus -0...assumed SNRs. ONGERUBRICEERD ONGERUBRICEERD I TNO reportI TNO-DV 2006 A518 47/51 1 t m 1 0.0 -.-.- 4 1 o,::---::: ::.: :---’ • -’"o0

  12. Novel sonar signal processing tool using Shannon entropy

    SciTech Connect

    Quazi, A.H.

    1996-06-01

    Traditionally, conventional signal processing extracts information from sonar signals using amplitude, signal energy or frequency domain quantities obtained using spectral analysis techniques. The object is to investigate an alternate approach which is entirely different than that of traditional signal processing. This alternate approach is to utilize the Shannon entropy as a tool for the processing of sonar signals with emphasis on detection, classification, and localization leading to superior sonar system performance. Traditionally, sonar signals are processed coherently, semi-coherently, and incoherently, depending upon the a priori knowledge of the signals and noise. Here, the detection, classification, and localization technique will be based on the concept of the entropy of the random process. Under a constant energy constraint, the entropy of a received process bearing finite number of sample points is maximum when hypothesis H{sub 0} (that the received process consists of noise alone) is true and decreases when correlated signal is present (H{sub 1}). Therefore, the strategy used for detection is: (I) Calculate the entropy of the received data; then, (II) compare the entropy with the maximum value; and, finally, (III) make decision: H{sub 1} is assumed if the difference is large compared to pre-assigned threshold and H{sub 0} is otherwise assumed. The test statistics will be different between entropies under H{sub 0} and H{sub 1}. Here, we shall show the simulated results for detecting stationary and non-stationary signals in noise, and results on detection of defects in a Plexiglas bar using an ultrasonic experiment conducted by Hughes. {copyright} {ital 1996 American Institute of Physics.}

  13. Neural networks for improved target differentiation and localization with sonar.

    PubMed

    Ayrulu, B; Barshan, B

    2001-04-01

    This study investigates the processing of sonar signals using neural networks for robust differentiation of commonly encountered features in indoor robot environments. Differentiation of such features is of interest for intelligent systems in a variety of applications. Different representations of amplitude and time-of-flight measurement patterns acquired from a real sonar system are processed. In most cases, best results are obtained with the low-frequency component of the discrete wavelet transform of these patterns. Modular and non-modular neural network structures trained with the back-propagation and generating-shrinking algorithms are used to incorporate learning in the identification of parameter relations for target primitives. Networks trained with the generating-shrinking algorithm demonstrate better generalization and interpolation capability and faster convergence rate. Neural networks can differentiate more targets employing only a single sensor node, with a higher correct differentiation percentage (99%) than achieved with previously reported methods (61-90%) employing multiple sensor nodes. A sensor node is a pair of transducers with fixed separation, that can rotate and scan the target to collect data. Had the number of sensing nodes been reduced in the other methods, their performance would have been even worse. The success of the neural network approach shows that the sonar signals do contain sufficient information to differentiate all target types, but the previously reported methods are unable to resolve this identifying information. This work can find application in areas where recognition of patterns hidden in sonar signals is required. Some examples are system control based on acoustic signal detection and identification, map building, navigation, obstacle avoidance, and target-tracking applications for mobile robots and other intelligent systems.

  14. Beaked Whales Respond to Simulated and Actual Navy Sonar

    DTIC Science & Technology

    2011-03-14

    fundamental frequency of MFA sonars, and it is possible that these harmonics may be involved in the response. Another hypothesis for why these tonal ... tonal components in the 3– 4 kHz band, a pseudorandom noise signal (PRN) with overall bandwidth and timing similar to MFA, and killer whale (ORCA...sufficient signal to noise ratio to use as stimuli. Harbor seals react to the calls of strange killer whales as a predator [33], and this is typical

  15. Function Analysis of AN/SQS-510 Hull Mounted Sonar

    DTIC Science & Technology

    2001-12-01

    Which Support Behavioural Function The hardware dependency of a function will be considered in general this is the AN SQS 510 system Superordinate...Identifying mission types • Using the preliminary function list to identify all major system functions • Organising the functions into a relationship...Humansystems Incorporated® AN SQSSlO Sonar: Function Analysis Page9 P517348.PDF [Page: 20 of 91] 4. Results The results are organised as follows

  16. Wideband Sonar Arrays for UUV and Weapon System Applications

    DTIC Science & Technology

    2012-11-01

    transducers find many applications in underwater vehicles. Two methods can be used to design wideband acoustic transducers . The multiply resonant transducer ...differences, and none has investigated the possible additional benefits of combining the two methods in a single transducer element for greater benefit than is...Medeiros CO-PI Information: None Abstract Wideband sonar transducers find many applications in underwater vehicles. Two methods can be used to

  17. Qualitative and quantitative processing of side-scan sonar data

    SciTech Connect

    Dwan, F.S.; Anderson, A.L.; Hilde, T.W.C. )

    1990-06-01

    Modern side-scan sonar systems allow vast areas of seafloor to be rapidly imaged and quantitatively mapped in detail. The application of remote sensing image processing techniques can be used to correct for various distortions inherent in raw sonography. Corrections are possible for water column, slant-range, aspect ratio, speckle and striping noise, multiple returns, power drop-off, and for georeferencing. The final products reveal seafloor features and patterns that are geometrically correct, georeferenced, and have improved signal/noise ratio. These products can be merged with other georeferenced data bases for further database management and information extraction. In order to compare data collected by different systems from a common area and to ground truth measurements and geoacoustic models, quantitative correction must be made for calibrated sonar system and bathymetry effects. Such data inversion must account for system source level, beam pattern, time-varying gain, processing gain, transmission loss, absorption, insonified area, and grazing angle effects. Seafloor classification can then be performed on the calculated back-scattering strength using Lambert's Law and regression analysis. Examples are given using both approaches: image analysis and inversion of data based on the sonar equation.

  18. Estimation and simulation of multi-beam sonar noise.

    PubMed

    Holmin, Arne Johannes; Korneliussen, Rolf J; Tjøstheim, Dag

    2016-02-01

    Methods for the estimation and modeling of noise present in multi-beam sonar data, including the magnitude, probability distribution, and spatial correlation of the noise, are developed. The methods consider individual acoustic samples and facilitate compensation of highly localized noise as well as subtraction of noise estimates averaged over time. The modeled noise is included in an existing multi-beam sonar simulation model [Holmin, Handegard, Korneliussen, and Tjøstheim, J. Acoust. Soc. Am. 132, 3720-3734 (2012)], resulting in an improved model that can be used to strengthen interpretation of data collected in situ at any signal to noise ratio. Two experiments, from the former study in which multi-beam sonar data of herring schools were simulated, are repeated with inclusion of noise. These experiments demonstrate (1) the potentially large effect of changes in fish orientation on the backscatter from a school, and (2) the estimation of behavioral characteristics such as the polarization and packing density of fish schools. The latter is achieved by comparing real data with simulated data for different polarizations and packing densities.

  19. Blue whales respond to simulated mid-frequency military sonar.

    PubMed

    Goldbogen, Jeremy A; Southall, Brandon L; DeRuiter, Stacy L; Calambokidis, John; Friedlaender, Ari S; Hazen, Elliott L; Falcone, Erin A; Schorr, Gregory S; Douglas, Annie; Moretti, David J; Kyburg, Chris; McKenna, Megan F; Tyack, Peter L

    2013-08-22

    Mid-frequency military (1-10 kHz) sonars have been associated with lethal mass strandings of deep-diving toothed whales, but the effects on endangered baleen whale species are virtually unknown. Here, we used controlled exposure experiments with simulated military sonar and other mid-frequency sounds to measure behavioural responses of tagged blue whales (Balaenoptera musculus) in feeding areas within the Southern California Bight. Despite using source levels orders of magnitude below some operational military systems, our results demonstrate that mid-frequency sound can significantly affect blue whale behaviour, especially during deep feeding modes. When a response occurred, behavioural changes varied widely from cessation of deep feeding to increased swimming speed and directed travel away from the sound source. The variability of these behavioural responses was largely influenced by a complex interaction of behavioural state, the type of mid-frequency sound and received sound level. Sonar-induced disruption of feeding and displacement from high-quality prey patches could have significant and previously undocumented impacts on baleen whale foraging ecology, individual fitness and population health.

  20. Blue whales respond to simulated mid-frequency military sonar

    PubMed Central

    Goldbogen, Jeremy A.; Southall, Brandon L.; DeRuiter, Stacy L.; Calambokidis, John; Friedlaender, Ari S.; Hazen, Elliott L.; Falcone, Erin A.; Schorr, Gregory S.; Douglas, Annie; Moretti, David J.; Kyburg, Chris; McKenna, Megan F.; Tyack, Peter L.

    2013-01-01

    Mid-frequency military (1–10 kHz) sonars have been associated with lethal mass strandings of deep-diving toothed whales, but the effects on endangered baleen whale species are virtually unknown. Here, we used controlled exposure experiments with simulated military sonar and other mid-frequency sounds to measure behavioural responses of tagged blue whales (Balaenoptera musculus) in feeding areas within the Southern California Bight. Despite using source levels orders of magnitude below some operational military systems, our results demonstrate that mid-frequency sound can significantly affect blue whale behaviour, especially during deep feeding modes. When a response occurred, behavioural changes varied widely from cessation of deep feeding to increased swimming speed and directed travel away from the sound source. The variability of these behavioural responses was largely influenced by a complex interaction of behavioural state, the type of mid-frequency sound and received sound level. Sonar-induced disruption of feeding and displacement from high-quality prey patches could have significant and previously undocumented impacts on baleen whale foraging ecology, individual fitness and population health. PMID:23825206

  1. Application of acoustic reflection tomography to sonar imaging.

    PubMed

    Ferguson, Brian G; Wyber, Ron J

    2005-05-01

    Computer-aided tomography is a technique for providing a two-dimensional cross-sectional view of a three-dimensional object through the digital processing of many one-dimensional views (or projections) taken at different look directions. In acoustic reflection tomography, insonifying the object and then recording the backscattered signal provides the projection information for a given look direction (or aspect angle). Processing the projection information for all possible aspect angles enables an image to be reconstructed that represents the two-dimensional spatial distribution of the object's acoustic reflectivity function when projected on the imaging plane. The shape of an idealized object, which is an elliptical cylinder, is reconstructed by applying standard backprojection, Radon transform inversion (using both convolution and filtered backprojections), and direct Fourier inversion to simulated projection data. The relative merits of the various reconstruction algorithms are assessed and the resulting shape estimates compared. For bandpass sonar data, however, the wave number components of the acoustic reflectivity function that are outside the passband are absent. This leads to the consideration of image reconstruction for bandpass data. Tomographic image reconstruction is applied to real data collected with an ultra-wideband sonar transducer to form high-resolution acoustic images of various underwater objects when the sonar and object are widely separated.

  2. Sonar Dome Reliability XVIII: Measured Deflections of the USS Kauffman Sonar Rubber Dome, 15-25 November 1992

    DTIC Science & Technology

    1994-01-07

    there was insufficient room left in the existing cableways for the addition of our system control cables. Thus, we requested a new cableway be installed...between the SRD area and the sonar equipment room, shown in Figures 6 and 7, to provide a pathway for these new cables. The new cableway would also...decided that a new separate cableway was not needed; the installation of the wave height sensors was made parallel with the ships rail instead of the

  3. Range compensation for backscattering measurements in the difference-frequency nearfield of a parametric sonar.

    PubMed

    Foote, Kenneth G

    2012-05-01

    Measurement of acoustic backscattering properties of targets requires removal of the range dependence of echoes. This process is called range compensation. For conventional sonars making measurements in the transducer farfield, the compensation removes effects of geometrical spreading and absorption. For parametric sonars consisting of a parametric acoustic transmitter and a conventional-sonar receiver, two additional range dependences require compensation when making measurements in the nonlinearly generated difference-frequency nearfield: an apparently increasing source level and a changing beamwidth. General expressions are derived for range compensation functions in the difference-frequency nearfield of parametric sonars. These are evaluated numerically for a parametric sonar whose difference-frequency band, effectively 1-6 kHz, is being used to observe Atlantic herring (Clupea harengus) in situ. Range compensation functions for this sonar are compared with corresponding functions for conventional sonars for the cases of single and multiple scatterers. Dependences of these range compensation functions on the parametric sonar transducer shape, size, acoustic power density, and hydrography are investigated. Parametric range compensation functions, when applied with calibration data, will enable difference-frequency echoes to be expressed in physical units of volume backscattering, and backscattering spectra, including fish-swimbladder-resonances, to be analyzed.

  4. Quantifying Effects of Mid-Frequency Sonar Transmissions on Fish and Whale

    DTIC Science & Technology

    2010-09-30

    different cruises with different vessels and TOPAS parametric sonars. The first calibration trial was conducted with R/V “G. O. Sars” in the Sørfolla fjord ...sonar during the calibration exercise with R/V “G. O. Sars” in Sørfolla fjord on 10 December 2008 has been addressed in a preliminary study (Foote et al

  5. Binaural sonar electronic travel aid provides vibrotactile cues for landmark, reflector motion and surface texture classification.

    PubMed

    Kuc, Roman

    2002-10-01

    Electronic travel aids (ETAs) for the blind commonly employ conventional time-of-flight sonars to provide range measurements, but their wide beams prevent accurate determination of object bearing. We describe a binaural sonar that detects objects over a wider bearing interval compared with a single transducer and also determines if the object lies to the left or right of the sonar axis in a robust manner. The sonar employs a pair of Polaroid 6500 ranging modules connected to Polaroid 7000 transducers operating simultaneously in a binaural array configuration. The sonar determines which transducer detects the echo first. An outward vergence angle between the transducers improves the first-echo detection reliability by increasing the delay between the two detected echoes, a consequence of threshold detection. We exploit this left/right detection capability in an ETA that provides vibrotactile feedback. Pager motors mount on both sides of the sonar, possibly worn on the user's wrists. The motor on the same side as the reflecting object vibrates with speed inversely related to range. As the sonar or object moves, vibration patterns provide landmark, motion and texture cues. Orienting the sonar at 45 degrees relative to the travel direction and passing a right-angle corner produces a characteristic vibrational pattern. When pointing the sonar at a moving object, such as a fluttering flag, the motors alternate in a manner to give the user a perception of the object motion. When the sonar translates or rotates to scan a foliage surface, the vibrational patterns are related to the surface scatterer distribution, allowing the user to identify the foliage.

  6. Characteristics of a sandy depositional lobe on the outer Mississippi fan from SeaMARC IA sidescan sonar images

    SciTech Connect

    Twichell, D.C.; Schwab, W.C. ); Nelson, C.H.; Lee, H.J. ); Kenyon, N.H. )

    1992-08-01

    SeaMARC IA sidescan sonar images of the distal reaches of a depositional lobe on the Mississippi Fan show that channelized rather than unconfined transport was the dominant transport mechanism for coarse-grained sediment during the formation of this part of the deep-sea fan. Overbank sheet flow of sands was not an important process in the transport and deposition of the sandy and silty sediment found on this fan. The dendritic distributary pattern and the high order of splaying of the channels, only one which appears to have been active at a time, suggest that coarse-grained deposits on this fan are laterally discontinuous.

  7. Extraction of small boat harmonic signatures from passive sonar.

    PubMed

    Ogden, George L; Zurk, Lisa M; Jones, Mark E; Peterson, Mary E

    2011-06-01

    This paper investigates the extraction of acoustic signatures from small boats using a passive sonar system. Noise radiated from a small boats consists of broadband noise and harmonically related tones that correspond to engine and propeller specifications. A signal processing method to automatically extract the harmonic structure of noise radiated from small boats is developed. The Harmonic Extraction and Analysis Tool (HEAT) estimates the instantaneous fundamental frequency of the harmonic tones, refines the fundamental frequency estimate using a Kalman filter, and automatically extracts the amplitudes of the harmonic tonals to generate a harmonic signature for the boat. Results are presented that show the HEAT algorithms ability to extract these signatures.

  8. Static analysis of a sonar dome rubber window

    NASA Technical Reports Server (NTRS)

    Lai, J. L.

    1978-01-01

    The application of NASTRAN (level 16.0.1) to the static analysis of a sonar dome rubber window (SDRW) was demonstrated. The assessment of the conventional model (neglecting the enclosed fluid) for the stress analysis of the SDRW was made by comparing its results to those based on a sophisticated model (including the enclosed fluid). The fluid was modeled with isoparametric linear hexahedron elements with approximate material properties whose shear modulus was much smaller than its bulk modulus. The effect of the chosen material property for the fluid is discussed.

  9. Performance of Passive and Active Sonars in the Philippine Sea

    DTIC Science & Technology

    2013-09-30

    Philippine Sea Arthur B. Baggeroer Massachusetts Institute of Technology Departments of Mechanical and Ocean Engineering Cambridge, MA 02139 phone: (617...to model the features of a CZ which we observed in the PhilSea09 experiment. The data from this found very abrupt transitions and into the CZ’s and...The CZ is one of the most notable features of deep ocean sound propagation. Several models for the sound speed profile have been used to model the

  10. Optimal Sensor Placement in Active Multistatic Sonar Networks

    DTIC Science & Technology

    2014-06-01

    monitored in order to protect them from hostile underwater assets. We consider discrete “ cookie cutter” sensors as well as various diffuse sensor models. By... cookie cutter sensor model, we are able to exclude even more suboptimal solutions by determining range-of-the-day, source and receiver circles. To...protect them from hostile underwater assets. We consider discrete “ cookie cutter” sensors as well as various diffuse sensor models. By showing that the

  11. Performance of Passive and Active Sonars in the Philippine Sea

    DTIC Science & Technology

    2014-09-30

    150 km, or two and one half CZ’s. We label such figures as a depth-direction sine 1Both the internal wave and RAM MATLAB codes were provided by Matt...solution reflects a CZ like behavior.) The figures have encapsulate the ray arrivals very Figure 2: Left: Directional wave spectra vs subaperture...no shallow rays near the surface. Significant energy does not appear until approximately 250 m. After this there are just two paths until 1500 m

  12. Shallow water imaging sonar system for environmental surveying. Final report

    SciTech Connect

    1998-05-01

    The scope of this research is to develop a shallow water sonar system designed to detect and map the location of objects such as hazardous wastes or discarded ordnance in coastal waters. The system will use high frequency wide-bandwidth imaging sonar, mounted on a moving platform towed behind a boat, to detect and identify objects on the sea bottom. Resolved images can be obtained even if the targets are buried in an overlayer of silt. The specific technical objective of this research was to develop and test a prototype system that is capable of (1) scan at high speeds (up to 10m/s), even in shallow water (depth to ten meters), without motion blurring or loss of resolution; (2) produce images of the bottom structure that are detailed enough for unambiguous detection of objects as small as 15cm, even if they are buried up to 30cm deep in silt or sand. The critical technology involved uses an linear FM (LFM) or similar complex waveform, which has a high bandwidth for good range resolution, with a long pulse length for similar Dopper resolution. The lone duration signal deposits more energy on target than a narrower pulse, which increases the signal-to-noise ratio and signal-to-clutter ratio. This in turn allows the use of cheap, lightweight, low power, piezoelectric transducers at the 30--500 kHz range.

  13. Cognitive adaptation of sonar gain control in the bottlenose dolphin.

    PubMed

    Kloepper, Laura N; Smith, Adam B; Nachtigall, Paul E; Buck, John R; Simmons, James A; Pacini, Aude F

    2014-01-01

    Echolocating animals adjust the transmit intensity and receive sensitivity of their sonar in order to regulate the sensation level of their echoes; this process is often termed automatic gain control. Gain control is considered not to be under the animal's cognitive control, but previous investigations studied animals ensonifying targets or hydrophone arrays at predictable distances. To test whether animals maintain gain control at a fixed level in uncertain conditions, we measured changes in signal intensity for a bottlenose dolphin (Tursiops truncatus) detecting a target at three target distances (2.5, 4 and 7 m) in two types of sessions: predictable and unpredictable. Predictable sessions presented the target at a constant distance; unpredictable sessions moved the target randomly between the three target positions. In the predictable sessions the dolphin demonstrated intensity distance compensation, increasing the emitted click intensity as the target distance increased. Additionally, as trials within sessions progressed, the animal adjusted its click intensity even from the first click in a click train, which is consistent with the animal expecting a target at a certain range. In the unpredictable sessions there was no significant difference of intensity with target distance until after the 7th click in a click train. Together, these results demonstrate that the bottlenose dolphin uses learning and expectation for sonar gain control.

  14. Controllable Sonar Lenses and Prisms Based on ERFs

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Sherrit, Stewart; Chang, Zensheu; Bao, Xiaoqi; Paustian, Iris; Lopes, Joseph; Folds, Donald

    2004-01-01

    Sonar-beam-steering devices of the proposed type would contain no moving parts and would be considerably smaller and less power-hungry, relative to conventional multiple-beam sonar arrays. The proposed devices are under consideration for installation on future small autonomous underwater vehicles because the sizes and power demands of conventional multiple-beam arrays are excessive, and motors used in single-beam mechanically scanned systems are also not reliable. The proposed devices would include a variety of electrically controllable acoustic prisms, lenses, and prism/lens combinations both simple and compound. These devices would contain electrorheological fluids (ERFs) between electrodes. An ERF typically consists of dielectric particles floating in a dielectric fluid. When an electric field is applied to the fluid, the particles become grouped into fibrils aligned in rows, with a consequent increase in the viscosity of the fluid and a corresponding increase in the speed of sound in the fluid. The change in the speed of sound increases with an increase in the applied electric field. By thus varying the speed of sound, one varies the acoustic index of refraction, analogously to varying the index of refraction of an optical lens or prism. In the proposed acoustic devices, this effect would be exploited to control the angles of refraction of acoustic beams, thereby steering the beams and, in the case of lenses, controlling focal lengths.

  15. Cognitive Adaptation of Sonar Gain Control in the Bottlenose Dolphin

    PubMed Central

    Kloepper, Laura N.; Smith, Adam B.; Nachtigall, Paul E.; Buck, John R.; Simmons, James A.; Pacini, Aude F.

    2014-01-01

    Echolocating animals adjust the transmit intensity and receive sensitivity of their sonar in order to regulate the sensation level of their echoes; this process is often termed automatic gain control. Gain control is considered not to be under the animal's cognitive control, but previous investigations studied animals ensonifying targets or hydrophone arrays at predictable distances. To test whether animals maintain gain control at a fixed level in uncertain conditions, we measured changes in signal intensity for a bottlenose dolphin (Tursiops truncatus) detecting a target at three target distances (2.5, 4 and 7 m) in two types of sessions: predictable and unpredictable. Predictable sessions presented the target at a constant distance; unpredictable sessions moved the target randomly between the three target positions. In the predictable sessions the dolphin demonstrated intensity distance compensation, increasing the emitted click intensity as the target distance increased. Additionally, as trials within sessions progressed, the animal adjusted its click intensity even from the first click in a click train, which is consistent with the animal expecting a target at a certain range. In the unpredictable sessions there was no significant difference of intensity with target distance until after the 7th click in a click train. Together, these results demonstrate that the bottlenose dolphin uses learning and expectation for sonar gain control. PMID:25153530

  16. Processing of AUV Sidescan Sonar Images for Enhancement and Classification

    NASA Astrophysics Data System (ADS)

    Honsho, C.; Asada, A.; Ura, T.; Kim, K.

    2014-12-01

    An arc volcano hosting a hydrothermal field was surveyed by using an autonomous underwater vehicle equipped with a sidescan sonar system and a multibeam echo sounder. The survey area is relatively small in area but has large variations in bathymetry and geology. To correct large geometric distortions in sidescan images, actual topographic cross sections cut by fan beams were taken into consideration instead of assuming flat bottoms. Beam pattern corrections were cautiously performed in combination with theoretical radiometric corrections for slant range and incident angle. These detailed geometric and radiometric corrections were efficient to patch neighboring images and build a complete picture of the whole survey area. Three textural attributes were computed from the corrected images by means of grey level co-occurrence matrices and used for the seafloor classification. As no ground truth data were available to us, we used a cluster analysis for the classification and obtained a result that seems relevant to the geological features suggested by the topography. Moreover, slopes of the caldera wall and of the central cones are clearly differentiated in the classification result, though the difference is not immediately obvious to our eyes. As one of the classes clearly delineates a known hydrothermal field, we expect by analogy that this class will highlight hydrothermal features in the survey area, helping to detect potential targets to be specifically investigated for mineral exploration. Numerical processing of sonar images effectively complements their visual inspection with human eyes and is helpful in providing a different perspective.

  17. Broadband sonar considerations for small underwater vehicle applications

    NASA Astrophysics Data System (ADS)

    Benjamin, Kim C.

    2003-10-01

    As underwater vehicles become more prevalent, so too does the design and integration of compact broadband sonar arrays. Rather than rely on conventional tonpilz technology, where the bandwidth is governed by the width of the transducer's mechanical resonance, designers must consider other transducer technologies that are better suited to small vehicle packaging constraints. These constraints include operational ruggedness, light weight, conformability, and low cost. This talk advocates the use of 1-3 piezocomposite and discusses the rationale behind such a selection. In going to a wideband material such as a 1-3 piezocomposite, with typical mechanical quality factors (Qm) around 2, the selection of where to place the resonance frequency differs from that of its tonpilz counterpart. For the tonpilz array, the sonar operational bandwidth is totally governed by the resonance response of the array element and is typically limited to approximately its 3-dB or half power points. Relaxor-based ferroelectric materials such as single crystal PMN-PT, which exhibit extremely large electromechanical coupling coefficients, cannot attain 3-dB bandwidths of a decade or more when configured in a tonpilz design. This presentation will discuss a 1-3 piezocomposite-based approach that places mechanical resonance near the upper band edge of an operational bandwidth of 1 decade (10-100 kHz).

  18. An underwater ship fault detection method based on Sonar image processing

    NASA Astrophysics Data System (ADS)

    Hong, Shi; Fang-jian, Shan; Bo, Cong; Wei, Qiu

    2016-02-01

    For the research of underwater ship fault detection method in conditions of sailing on the ocean especially in poor visibility muddy sea, a fault detection method under the assist of sonar image processing was proposed. Firstly, did sonar image denoising using the algorithm of pulse coupled neural network (PCNN); secondly, edge feature extraction for the image after denoising was carried out by morphological wavelet transform; Finally, interested regions Using relevant tracking method were taken, namely fault area mapping. The simulation results presented here proved the feasibility and effectiveness of the sonar image processing in underwater fault detection system.

  19. Simulation, manufacturing, and evaluation of a sonar for a miniaturized submersible explorer.

    PubMed

    Jonsson, Jonas; Edqvist, Erik; Kratz, Henrik; Almqvist, Monica; Thornell, Greger

    2010-01-01

    Single-beam side-scan sonar elements, to be fitted on a miniaturized submersible, are here simulated, manufactured, and evaluated. Finite element analysis simulations are compared with measurements, and an overall observation is that the agreement between simulations and measurements deviates from the measured values of 1.5 to 2 degrees, for the narrow lobe angle, by less than 10% for most models. An overall finding is that the lobe width along the track direction can be accurately simulated and, hence, the resolution of the sonars can be predicted. This paper presents, to the authors' knowledge, the world's smallest side-scan sonars.

  20. The Effects of Towfish Motion on Sidescan Sonar Images: Extension to a Multiple-Beam Device

    DTIC Science & Technology

    1994-02-01

    Towfish Motion on Sidescan Sonar Images: Extension to a Multiple -Beam Device Acceso NTIS CRA&I S.D. Anstee u; ,-, o* , J.* ttiicatorn By "By...THE EFFECTS OF TOWFISH MOTION ON SIDESCAN SONAR IMAGES: EXTENSION TO A MULTIPLE -BEAM DEVICE S, S.D. ANSTEE 6 2 9 Nm MRL-TN-660 FEBRUARY 1994 Al DTIC...previously used to estimate the geometrical effects oftowjish motion on single-beam sidescan sonar images is modified to simulate a multiple -beam

  1. Early Results from the IMI-30 Towed Sonar System

    NASA Astrophysics Data System (ADS)

    Edwards, M. H.; Rognstad, M. R.; Tottori, S. N.; Davis, R. B.; Appelgate, T. B.; Johnson, P. D.; Kevis-Stirling, A.

    2006-12-01

    The Hawaii Mapping Research Group (HMRG) of the University of Hawaii has designed and built a 30 kHz deep-towed sonar, the IMI-30, which simultaneously collects interferometric bathymetry and backscatter data. The sonar is capable of being deployed to 6000 m water depth, where it is towed 100-500 m above the seafloor yielding a total swath width of 1-5 km for sidescan and somewhat less than that for bathymetry. The across-track resolution is <10 m for bathymetry depending on towing geometry and substrate type, and 0.3- 3 m for sidescan, depending on the selected transmit pulse length and tow vehicle altitude. The along-track resolution, which is dependent on vehicle speed and pulse repetition rate, varies between 0.6 and 3 meters. Here we report on data collected by the system during two different deployments in the Pacific: the IMI-30's initial field program in the Lau Basin in 2004 and the most recent survey using the system, south of Oahu in June of 2006. Between the 2004 Lau program and the June 2006 survey, several engineering improvements were made including: 1) changing the housings of the side-looking transducers from cast polyurethane to oil- filled polyethylene; 2) adding syntactic foam baffling to reduce surface bounce; 3) synchronizing sound velocimeter measurements with sonar transmit; 4) adding sub-bottom transducers and associated electronics to the tow vehicle; 5) adding two additional side-looking transducer rows per side, and 6) upgrading the surface and subsurface power supplies. This engineering effort has improved reliability of the system by eliminating transducer failures caused by seawater leakage and power supply over-temperature shutdown in tropical waters. Reducing the system noise - electrical, hydrodynamic, and acoustic - has improved data quality and extended the swath width. The addition of sub-bottom data acquisition further increases the utility of the IMI-30 system. Our presentation will document the engineering effort and

  2. First results of a deep tow CHIRP sonar seafloor imaging system

    USGS Publications Warehouse

    Parent, M.; Fang, Changle; O'Brien, Thomas F.; Danforth, William W.

    1993-01-01

    The latest and most innovative technology has been applied towards the development of a full-ocean depth multi-sensor sonar system using linear swept-FM (Chirp) technology. The seafloor imaging system (SIS- 7000) described herein uses Chirp sidescan sonar to provide high resolution imagery at long range, and Chirp subbottom sonar to provide high resolution profiles in both the near bottom and deeper subbottom. The tow vehicle contains a suite of full-ocean depth instrumentation for measuring various oceanographic parameters and for monitoring vehicle status. Top side systems include a sonar display and data logging system as well as real-time sensor status display and tow vehicle control system. This paper will present an overview of this system, describe its technology and capabilities, and present some initial results. 

  3. Sonar sound groups and increased terminal buzz duration reflect task complexity in hunting bats.

    PubMed

    Hulgard, Katrine; Ratcliffe, John M

    2016-02-09

    More difficult tasks are generally regarded as such because they demand greater attention. Echolocators provide rare insight into this relationship because biosonar signals can be monitored. Here we show that bats produce longer terminal buzzes and more sonar sound groups during their approach to prey under presumably more difficult conditions. Specifically, we found Daubenton's bats, Myotis daubentonii, produced longer buzzes when aerial-hawking versus water-trawling prey, but that bats taking revolving air- and water-borne prey produced more sonar sound groups than did the bats when taking stationary prey. Buzz duration and sonar sound groups have been suggested to be independent means by which bats attend to would-be targets and other objects of interest. We suggest that for attacking bats both should be considered as indicators of task difficulty and that the buzz is, essentially, an extended sonar sound group.

  4. Sonar sound groups and increased terminal buzz duration reflect task complexity in hunting bats

    PubMed Central

    Hulgard, Katrine; Ratcliffe, John M.

    2016-01-01

    More difficult tasks are generally regarded as such because they demand greater attention. Echolocators provide rare insight into this relationship because biosonar signals can be monitored. Here we show that bats produce longer terminal buzzes and more sonar sound groups during their approach to prey under presumably more difficult conditions. Specifically, we found Daubenton’s bats, Myotis daubentonii, produced longer buzzes when aerial-hawking versus water-trawling prey, but that bats taking revolving air- and water-borne prey produced more sonar sound groups than did the bats when taking stationary prey. Buzz duration and sonar sound groups have been suggested to be independent means by which bats attend to would-be targets and other objects of interest. We suggest that for attacking bats both should be considered as indicators of task difficulty and that the buzz is, essentially, an extended sonar sound group. PMID:26857019

  5. Mobile Robot Sonar Backscatter Algorithm for Automatically Distinguishing Walls, Fences and Hedges

    NASA Astrophysics Data System (ADS)

    Gao, Wen; Hinders, Mark

    2006-03-01

    An algorithm to distinguish brick walls, picket fences and hedges based on backscattered sonar echoes is described. The echo data are acquired by a mobile robot with a 50kHz computer-controlled sonar scanning system packaged as its sensor head. For several locations along a wall, fence or hedge a fan of backscatter sonar echoes are acquired and digitized as the sonar transducer is swept over a horizontal arc. Backscatter is then plotted vs. scan angle, with a series deformable templates fit to this data. The number of peaks in the best-fitting template indicates the presence and location of retro-reflectors, and allows automatic categorization of the various fences, hedges and brick walls.

  6. AUTOMATED PRODUCTION OF SEAGRASS MAPS FROM SIDESCAN SONAR IMAGERY: ACCURACY, VARIABILITY AND PATCH RESOLUTION

    EPA Science Inventory

    Maps of seagrass beds are useful for monitoring estuarine condition, managing habitats, and modeling estuarine processes. We recently developed inexpensive methods for collecting and classifying sidescan sonar (SSS) imagery for seagrass presence in turbid waters as shallow as 1-...

  7. Digital processing of side-scan sonar data with the Woods Hole image processing system software

    USGS Publications Warehouse

    Paskevich, Valerie F.

    1992-01-01

    Since 1985, the Branch of Atlantic Marine Geology has been involved in collecting, processing and digitally mosaicking high and low-resolution side-scan sonar data. Recent development of a UNIX-based image-processing software system includes a series of task specific programs for processing side-scan sonar data. This report describes the steps required to process the collected data and to produce an image that has equal along- and across-track resol

  8. Passive Sonar Target Recognition Using a Back-Propagating Neural Network

    DTIC Science & Technology

    1991-06-01

    to train our neural network. Chapter three discusses the development of the sonar target model and some of its properties and assumptions. Chapter...through noise and other disturbances. In applying this property to sonar targets, this means the ability to identify a target even when it undergoes... properties . Some applications have shown that neural networks can learn special kinship patterns among families. After memorizing the genealogies of

  9. Comparison of Sonar Discrimination by an Echolocating Dolphin and a Counterpropagation Neural Network

    DTIC Science & Technology

    1992-09-01

    AND SUBTITLE 5 FUNDING NUMBERS COMPARISON OF SONAR DISCRIMINATION BY AN ECHOLOCATING PR: MMB2 DOLPHIN AND A COUNTERPROPAGATION NEURAL NETWORK PE...COMPARISON OF SONAR DISCRIMINATION BY AN constanB-1 filter cal fe expressed as ECIHOLOCATING DOLPHIN AND A COUNTERPROPAGATION 2Q-1 NEURAL NETWORK ’ " -- 1...In this study, a counterpropagation artificial layer of N+1 elements, a Kohonen layer of N elements neural network was used to examine the broadband

  10. Quantifying Effects of Mid-Frequency Sonar Transmissions on Fish and Whale Behavior

    DTIC Science & Technology

    2012-09-30

    on Fish and Whale Behavior Kenneth G. Foote Woods Hole Oceanographic Institution 98 Water Street Woods Hole, MA 02543 phone: (508) 289-2445...understand and quantify effects of mid-frequency (MF) sonar on fish and whale behavior through direct observation, and to investigate the potential...usefulness of MF sonar in acoustic measurements of fish , including stock assessments. OBJECTIVES The initial objectives are to prove the usefulness of

  11. Side-scan sonar imaging of the Colorado River, Grand Canyon

    USGS Publications Warehouse

    Anima, Roberto; Wong, Florence L.; Hogg, David; Galanis, Peter

    2007-01-01

    This paper presents data collection methods and side-scan sonar data collected along the Colorado River in Grand Canyon in August and September of 2000. The purpose of the data collection effort was to image the distribution of sand between Glen Canyon Dam and river mile 87.4 before and after the 31,600 cfs flow of September 6-8. The side-scan sonar imaging focused on pools between rapids but included smaller rapids where possible.

  12. Dynamic Response of an Insonified Sonar Window Interacting with a Tonpilz Transducer Array

    DTIC Science & Technology

    2007-01-03

    NUWC-NPT Technical Report 11,781 3 January 2007 Dynamic Response of an Insonified Sonar Window Interacting with a Tonpilz Transducer Array Andrew J...Code 1516) for their discussions on Tonpilz transducer behavior Reviewed and Approved: 3 January 2007 s S. Griffin Head, Autonomous Systems and...FUNDING NUMBERS Dynamic Response of an Insonified Sonar Window Interacting with a Tonpilz Transducer Array 6. AUTHOR(S) Andrew J. Hull 7. PERFORMING

  13. Echo tracker/range finder for radars and sonars

    NASA Technical Reports Server (NTRS)

    Constantinides, N. J. (Inventor)

    1982-01-01

    An echo tracker/range finder or altimeter is described. The pulse repetition frequency (PFR) of a predetermined plurality of transmitted pulses is adjusted so that echo pulses received from a reflecting object are positioned between transmitted pulses and divided their interpulse time interval into two time intervals having a predetermined ratio with respect to each other. The invention described provides a means whereby the arrival time of a plurality of echo pulses is defined as the time at which a composite echo pulse formed of a sum of the individual echo pulses has the highest amplitude. The invention is applicable to radar systems, sonar systems, or any other kind of system in which pulses are transmitted and echoes received therefrom.

  14. Side-looking sonar backscatter response at dual frequencies

    NASA Astrophysics Data System (ADS)

    Ryan, William B. F.; Flood, Roger D.

    1996-12-01

    Dual-frequency side-looking sonars have the potential to be used as remote sensing tools to characterize subaqueous terrains. In one case study of the carbonate-ooze-coated Blake Plateau off-shore of Georgia, U.S.A., the difference in acoustic attenuation for 50 and 20 mm wavelengths (30 and 72 kHz frequency) permits the discrimination of sub-bottom scatterers from seabed surface textural features to reveal patchy regions where a buried hard ground had been pock-marked by karst-like depressions. In a second study of the Upper Hudson River in New York, U.S.A., related to environmental contaminates, the backscatter response at 15 and 3 mm acoustic wavelengths (100 and 500 kHz frequency) serves as a useful proxy for sediment grain size with coarser detritus distinguished from finer sediments. Sand and gravel regions inferred from the backscatter were confirmed by ground truth sampling.

  15. Processing techniques for digital sonar images from GLORIA.

    USGS Publications Warehouse

    Chavez, P.S.

    1986-01-01

    Image processing techniques have been developed to handle data from one of the newest members of the remote sensing family of digital imaging systems. This paper discusses software to process data collected by the GLORIA (Geological Long Range Inclined Asdic) sonar imaging system, designed and built by the Institute of Oceanographic Sciences (IOS) in England, to correct for both geometric and radiometric distortions that exist in the original 'raw' data. Preprocessing algorithms that are GLORIA-specific include corrections for slant-range geometry, water column offset, aspect ratio distortion, changes in the ship's velocity, speckle noise, and shading problems caused by the power drop-off which occurs as a function of range.-from Author

  16. Application of Giant Magnetostrictive Materials for Sonar Transducers

    NASA Astrophysics Data System (ADS)

    Long, Nguyen Thang; van Hien, Nguyen; Thuy, Nguyen Phu; Hien, Vu The

    2001-04-01

    Giant magnetostrictive material (Terfenol-D) has been extensively used in many applications such as actuators and sonar projectors. However, its major disadvantage is the relative high price due to the complication of manufacturing process. A high strain at moderate field can only be obtained with the single crystal or grain oriented polycrystal. In addition, the use of Terfenol-D is limited at high frequencies because its electrical conductivity is as high as metals. Overcoming this problem by using laminated or rolled sheets of Terfenol-D requires expensive techniques due to their brittleness. In this paper, we present studies on the behavior of Terfenol-D rod under dynamic condition in a Tonpilz type transducer. In addition, a Zinc-bonded sample is prepared and measured to compare with that of the bulk material.

  17. Sonar atlas of caverns comprising the U.S. Strategic Petroleum Reserve. Volume 3, Bryan Mound Site, Texas.

    SciTech Connect

    Rautman, Christopher Arthur; Lord, Anna Snider

    2007-09-01

    Downhole sonar surveys from the four active U.S. Strategic Petroleum Reserve sites have been modeled and used to generate a four-volume sonar atlas, showing the three-dimensional geometry of each cavern. This volume 3 focuses on the Bryan Mound SPR site, located in southeastern Texas. Volumes 1, 2, and 4, respectively, present images for the Bayou Choctaw SPR site, Louisiana, the Big Hill SPR site, Texas, and the West Hackberry SPR site, Louisiana. The atlas uses a consistent presentation format throughout. The basic geometric measurements provided by the down-cavern surveys have also been used to generate a number of geometric attributes, the values of which have been mapped onto the geometric form of each cavern using a color-shading scheme. The intent of the various geometrical attributes is to highlight deviations of the cavern shape from the idealized cylindrical form of a carefully leached underground storage cavern in salt. The atlas format does not allow interpretation of such geometric deviations and anomalies. However, significant geometric anomalies, not directly related to the leaching history of the cavern, may provide insight into the internal structure of the relevant salt dome.

  18. Sonar atlas of caverns comprising the U.S. Strategic Petroleum Reserve. Volume 2, Big Hill Site, Texas.

    SciTech Connect

    Rautman, Christopher Arthur; Lord, Anna Snider

    2007-08-01

    Downhole sonar surveys from the four active U.S. Strategic Petroleum Reserve sites have been modeled and used to generate a four-volume sonar atlas, showing the three-dimensional geometry of each cavern. This volume 2 focuses on the Big Hill SPR site, located in southeastern Texas. Volumes 1, 3, and 4, respectively, present images for the Bayou Choctaw SPR site, Louisiana, the Bryan Mound SPR site, Texas, and the West Hackberry SPR site, Louisiana. The atlas uses a consistent presentation format throughout. The basic geometric measurements provided by the down-cavern surveys have also been used to generate a number of geometric attributes, the values of which have been mapped onto the geometric form of each cavern using a color-shading scheme. The intent of the various geometrical attributes is to highlight deviations of the cavern shape from the idealized cylindrical form of a carefully leached underground storage cavern in salt. The atlas format does not allow interpretation of such geometric deviations and anomalies. However, significant geometric anomalies, not directly related to the leaching history of the cavern, may provide insight into the internal structure of the relevant salt dome.

  19. Sonar atlas of caverns comprising the U.S. Strategic Petroleum Reserve. Volume 4, West Hackberry site, Louisiana.

    SciTech Connect

    Rautman, Christopher Arthur; Lord, Anna Snider

    2007-09-01

    Downhole sonar surveys from the four active U.S. Strategic Petroleum Reserve sites have been modeled and used to generate a four-volume sonar atlas, showing the three-dimensional geometry of each cavern. This volume 4 focuses on the West Hackberry SPR site, located in southwestern Louisiana. Volumes 1, 2, and 3, respectively, present images for the Bayou Choctaw SPR site, Louisiana, the Big Hill SPR site, Texas, and the Bryan Mound SPR site, Texas. The atlas uses a consistent presentation format throughout. The basic geometric measurements provided by the down-cavern surveys have also been used to generate a number of geometric attributes, the values of which have been mapped onto the geometric form of each cavern using a color-shading scheme. The intent of the various geometrical attributes is to highlight deviations of the cavern shape from the idealized cylindrical form of a carefully leached underground storage cavern in salt. The atlas format does not allow interpretation of such geometric deviations and anomalies. However, significant geometric anomalies, not directly related to the leaching history of the cavern, may provide insight into the internal structure of the relevant salt dome.

  20. Sonar atlas of caverns comprising the U.S. Strategic Petroleum Reserve. Volume 1, Bayou Choctaw site, Louisiana.

    SciTech Connect

    Rautman, Christopher Arthur; Lord, Anna Snider

    2007-10-01

    Downhole sonar surveys from the four active U.S. Strategic Petroleum Reserve sites have been modeled and used to generate a four-volume sonar atlas, showing the three-dimensional geometry of each cavern. This volume 1 focuses on the Bayou Choctaw SPR site, located in southern Louisiana. Volumes 2, 3, and 4, respectively, present images for the Big Hill SPR site, Texas, the Bryan Mound SPR site, Texas, and the West Hackberry SPR site, Louisiana. The atlas uses a consistent presentation format throughout. The basic geometric measurements provided by the down-cavern surveys have also been used to generate a number of geometric attributes, the values of which have been mapped onto the geometric form of each cavern using a color-shading scheme. The intent of the various geometrical attributes is to highlight deviations of the cavern shape from the idealized cylindrical form of a carefully leached underground storage cavern in salt. The atlas format does not allow interpretation of such geometric deviations and anomalies. However, significant geometric anomalies, not directly related to the leaching history of the cavern, may provide insight into the internal structure of the relevant salt dome.

  1. Processing and analysis of Simrad multibeam sonar data

    NASA Astrophysics Data System (ADS)

    Mitchell, Neil C.

    1996-12-01

    The common approach to analysing data collected with multibeam and sidescan sonars is to visually interpret charts of contoured bathymetry and mosaics of seabed images. However, some of the information content is lost by processing the data into charts because this involves some averaging; the analysis might uncover more information if done on the data at an earlier stage in the processing. Motivated by this potential, I have created a software system which can be used to analyse data collected with Simrad EM1000 (shallow water) and EM12 (deep water) multibeam sonars, as well as to generate bathymetry contour charts and backscatter mosaics. The system includes data preprocessing, such as navigation filtering, depth filtering (removal of outlying values), and amplitude mapping using the multibeam bathymetry to correctly position image pixels across the swath. The data attributes that can be analysed include the orientation and slope of the seafloor, and the mean signal strength for each sounding. To determine bathymetry attributes such as slope, the soundings across a number of beams and across a series of pings are grouped and a least-squares plane fitted to them. Bathymetric curvature is obtained by detrending the grouped data using the least-squares plane and fitting a paraboloid to the residuals. The magnitudes and signs of the paraboloid's coefficients reveal depressions and hills and their orientations. Furthermore, the seafloor geology can be classified using a simple combination of these attributes. For example, flat-lying sediments can be classified where the backscatter, slope and curvature fall below specified values.

  2. Advanced piezoelectric single crystal based transducers for naval sonar applications

    NASA Astrophysics Data System (ADS)

    Snook, Kevin A.; Rehrig, Paul W.; Hackenberger, Wesley S.; Jiang, Xiaoning; Meyer, Richard J., Jr.; Markley, Douglas

    2005-05-01

    TRS is developing new transducers based on single crystal piezoelectric materials such as Pb(Mg1/3Nb2/3)x-1TixO3 (PMN-PT). Single crystal piezoelectrics such as PMN-PT exhibit very high piezoelectric coefficients (d33 ~ 1800 to >2000 pC/N) and electromechanical coupling factors (k33 > 0.9), respectively, which may be exploited for improving the performance of broad bandwidth and high frequency sonar. Apart from basic performance, much research has been done on reducing the size and increasing the output power of tonpilz transducers for sonar applications. Results are presented from two different studies. "33" mode single crystal tonpilz transducers have reduced stack lengths due to their low elastic stiffness relative to PZTs, however, this produces non-ideal aspect ratios due to large lateral dimensions. Alternative "31" resonance mode tonpilz elements are proposed to improve performance over these "33" designs. d32 values as high as 1600 pC/N have been observed, and since prestress is applied perpendicular to the poling direction, "31" mode Tonpilz elements exhibit lower loss and higher reliability than "33" mode designs. Planar high power tonpilz arrays are the optimum way to obtain the required acoustic pressure and bandwidth for small footprint, high power sensors. An important issue for these sensors is temperature and prestress stability, since fluctuations in tonpilz properties affects power delivery and sensing electronic design. TRS used the approach of modifying the composition of PMN-PT to improve the temperature dependence of properties of the material. Results show up to a 50% decrease in temperature change while losing minimal source level.

  3. Bats' avoidance of real and virtual objects: implications for the sonar coding of object size.

    PubMed

    Goerlitz, Holger R; Genzel, Daria; Wiegrebe, Lutz

    2012-01-01

    Fast movement in complex environments requires the controlled evasion of obstacles. Sonar-based obstacle evasion involves analysing the acoustic features of object-echoes (e.g., echo amplitude) that correlate with this object's physical features (e.g., object size). Here, we investigated sonar-based obstacle evasion in bats emerging in groups from their day roost. Using video-recordings, we first show that the bats evaded a small real object (ultrasonic loudspeaker) despite the familiar flight situation. Secondly, we studied the sonar coding of object size by adding a larger virtual object. The virtual object echo was generated by real-time convolution of the bats' calls with the acoustic impulse response of a large spherical disc and played from the loudspeaker. Contrary to the real object, the virtual object did not elicit evasive flight, despite the spectro-temporal similarity of real and virtual object echoes. Yet, their spatial echo features differ: virtual object echoes lack the spread of angles of incidence from which the echoes of large objects arrive at a bat's ears (sonar aperture). We hypothesise that this mismatch of spectro-temporal and spatial echo features caused the lack of virtual object evasion and suggest that the sonar aperture of object echoscapes contributes to the sonar coding of object size.

  4. A novel approach to surveying sturgeon using side-scan sonar and occupancy modeling

    USGS Publications Warehouse

    Flowers, H. Jared; Hightower, Joseph E.

    2013-01-01

    Technological advances represent opportunities to enhance and supplement traditional fisheries sampling approaches. One example with growing importance for fisheries research is hydroacoustic technologies such as side-scan sonar. Advantages of side-scan sonar over traditional techniques include the ability to sample large areas efficiently and the potential to survey fish without physical handling-important for species of conservation concern, such as endangered sturgeons. Our objectives were to design an efficient survey methodology for sampling Atlantic Sturgeon Acipenser oxyrinchus by using side-scan sonar and to developmethods for analyzing these data. In North Carolina and South Carolina, we surveyed six rivers thought to contain varying abundances of sturgeon by using a combination of side-scan sonar, telemetry, and video cameras (i.e., to sample jumping sturgeon). Lower reaches of each river near the saltwater-freshwater interface were surveyed on three occasions (generally successive days), and we used occupancy modeling to analyze these data.We were able to detect sturgeon in five of six rivers by using these methods. Side-scan sonar was effective in detecting sturgeon, with estimated gear-specific detection probabilities ranging from 0.2 to 0.5 and river-specific occupancy estimates (per 2-km river segment) ranging from 0.0 to 0.8. Future extensions of this occupancy modeling framework will involve the use of side-scan sonar data to assess sturgeon habitat and abundance in different river systems.

  5. Near-real-time mosaics from high-resolution side-scan sonar

    USGS Publications Warehouse

    Danforth, William W.; O'Brien, Thomas F.; Schwab, W.C.

    1991-01-01

    High-resolution side-scan sonar has proven to be a very effective tool for stuyding and understanding the surficial geology of the seafloor. Since the mid-1970s, the US Geological Survey has used high-resolution side-scan sonar systems for mapping various areas of the continental shelf. However, two problems typically encountered included the short range and the high sampling rate of high-resolution side-scan sonar systems and the acquisition and real-time processing of the enormous volume of sonar data generated by high-resolution suystems. These problems were addressed and overcome in August 1989 when the USGS conducted a side-scan sonar and bottom sampling survey of a 1000-sq-km section of the continental shelf in the Gulf of Farallones located offshore of San Francisco. The primary goal of this survey was to map an area of critical interest for studying continental shelf sediment dynamics. This survey provided an opportunity to test an image processing scheme that enabled production of a side-scan sonar hard-copy mosaic during the cruise in near real-time.

  6. Sidescan-sonar mapping of benthic trawl marks on the shelf and slope off Eureka, California

    USGS Publications Warehouse

    Friedlander, A.M.; Boehlert, G.W.; Field, M.E.; Mason, J.E.; Gardner, J.V.; Dartnell, P.

    1999-01-01

    The abundance and orientation of trawl marks was quantified over an extensive portion (>2700 km2) of the Eureka, California, outer shelf and slope, an important commercial bottom trawling ground for such high-value species as rockfish, sole, and sablefish. Fishing logbook data indicate that the entire reporting area was trawled about one and a half times on an average annual basis and that some areas were trawled over three times annually. High-resolution sidescan-sonar images of the study area revealed deep gouges on the seafloor, caused by heavy steel trawl doors that act to weigh down and spread open the bottom trawls. These trawl marks are commonly oriented parallel to bathymetric contours and many could be traced for several kilometers. Trawl marks showed a quadratic relationship in relation to water depth, with the greatest number of trawl marks observed at ~400 m. There was a significant positive correlation between the number of trawl marks observed on the sidescan images and the number of annual trawl hours logged within reporting areas. This finding indicates that acoustic remote sensing is a promising independent approach to evaluate fishing effort on a scale consistent with commercial fishing activities. Bottom trawling gear is known to modify seafloor habitats by altering benthic habitat complexity and by removing or damaging infauna and sessile organisms. Identifying the extent of trawling in these areas may help determine the effects of this type of fishing gear on the benthos and develop indices of habitat disturbance caused by fishing activities.

  7. Sidescan sonar imagery and surficial geologic interpretation of the sea floor off Branford, Conneticut

    USGS Publications Warehouse

    Poppe, L.J.; Paskevich, V.F.; Moser, M.S.; DiGiacomo-Cohen, M. L.; Christman, E.B.

    2004-01-01

    distribution and transport of bottom sediments and the distribution of benthic habitats and associated infaunal community structures; and (3) providing a detailed framework for future research, monitoring, and management activities. The sidescan sonar mosaic also serves as a base map for subsequent sedimentological, geochemical, and biological observations, because precise information on environmental setting is important for selection of sampling sites and for appropriate interpretation of point measurements.

  8. The paradox of drowned reefs: A Caribbean example mapped using SeaMARC II side-scan sonar

    SciTech Connect

    Grote, D.; Mann, P. )

    1990-05-01

    Three models for the drowning of carbonate platforms and associated fringing coral reefs include (1) rapid submergence below the euphotic zone by tectonic subsidence and sea level rise; (2) excess nutrients in the water; and (3) burial by prograding marine siliclastic sediments. To examine these mechanisms on a regional scale, the authors mapped drowned barrier reef tracts around the active carbonate banks of the Nicaraguan Rise using SeaMARC II sidescan sonar, 3.5 KHz, and digital single channel reflection techniques. The reef tracts exhibited high sonar backscatter and were prominently displayed on sidescan images. Characteristic features of the reef tracts include (1) uneroded and slightly sinuous mounds that crop out on the sea floor and closely following bathymetric contours; (2) reef mounds that typically occur in stairstep sets of two to three terraces; (3) water depths at the crest of the reef mounds that range from 1,050 to 1,500 m; and (4) reef mounds that extend for 1,200 km around the base of the slope (depth 1,300 m) of an active carbonate platform in a moderately active, intraplate setting (Pedro Bank) and along the crest of a submerged fault block in a highly active, interplate setting (Bay Islands Ridge, ridge crest depth at 1,600 m). Because these newly discovered reef tracts have not been dredged, their ages and compositions remain unknown. Based on the observed sea floor outcrop, regional extent, and approximate correlation in water depth of the reef tracts, mechanisms 1 and 2 appear to be the most likely drowning mechanisms.

  9. AUV SLAM and Experiments Using a Mechanical Scanning Forward-Looking Sonar

    PubMed Central

    He, Bo; Liang, Yan; Feng, Xiao; Nian, Rui; Yan, Tianhong; Li, Minghui; Zhang, Shujing

    2012-01-01

    Navigation technology is one of the most important challenges in the applications of autonomous underwater vehicles (AUVs) which navigate in the complex undersea environment. The ability of localizing a robot and accurately mapping its surroundings simultaneously, namely the simultaneous localization and mapping (SLAM) problem, is a key prerequisite of truly autonomous robots. In this paper, a modified-FastSLAM algorithm is proposed and used in the navigation for our C-Ranger research platform, an open-frame AUV. A mechanical scanning imaging sonar is chosen as the active sensor for the AUV. The modified-FastSLAM implements the update relying on the on-board sensors of C-Ranger. On the other hand, the algorithm employs the data association which combines the single particle maximum likelihood method with modified negative evidence method, and uses the rank-based resampling to overcome the particle depletion problem. In order to verify the feasibility of the proposed methods, both simulation experiments and sea trials for C-Ranger are conducted. The experimental results show the modified-FastSLAM employed for the navigation of the C-Ranger AUV is much more effective and accurate compared with the traditional methods. PMID:23012549

  10. AUV SLAM and experiments using a mechanical scanning forward-looking sonar.

    PubMed

    He, Bo; Liang, Yan; Feng, Xiao; Nian, Rui; Yan, Tianhong; Li, Minghui; Zhang, Shujing

    2012-01-01

    Navigation technology is one of the most important challenges in the applications of autonomous underwater vehicles (AUVs) which navigate in the complex undersea environment. The ability of localizing a robot and accurately mapping its surroundings simultaneously, namely the simultaneous localization and mapping (SLAM) problem, is a key prerequisite of truly autonomous robots. In this paper, a modified-FastSLAM algorithm is proposed and used in the navigation for our C-Ranger research platform, an open-frame AUV. A mechanical scanning imaging sonar is chosen as the active sensor for the AUV. The modified-FastSLAM implements the update relying on the on-board sensors of C-Ranger. On the other hand, the algorithm employs the data association which combines the single particle maximum likelihood method with modified negative evidence method, and uses the rank-based resampling to overcome the particle depletion problem. In order to verify the feasibility of the proposed methods, both simulation experiments and sea trials for C-Ranger are conducted. The experimental results show the modified-FastSLAM employed for the navigation of the C-Ranger AUV is much more effective and accurate compared with the traditional methods.

  11. Monitoring the solid-liquid interface in tanks using profiling sonar and 3D visualization techniques

    NASA Astrophysics Data System (ADS)

    Sood, Nitin; Zhang, Jinsong; Roelant, David; Srivastava, Rajiv

    2005-03-01

    Visualization of the interface between settled solids and the optically opaque liquid above is necessary to facilitate efficient retrieval of the high-level radioactive waste (HLW) from underground storage tanks. A profiling sonar was used to generate 2-D slices across the settled solids at the bottom of the tank. By incrementally rotating the sonar about its centerline, slices of the solid-liquid interface can be imaged and a 3-D image of the settled solids interface generated. To demonstrate the efficacy of the sonar in real-time solid-liquid interface monitoring systems inside HLW tanks, two sets of experiments were performed. First, various solid objects and kaolin clay (10 μm dia) were successfully imaged while agitating with 30% solids (by weight) entrained in the liquid. Second, a solid with a density similar to that of the immersed fluid density was successfully imaged. Two dimensional (2-D) sonar images and the accuracy and limitations of the in-tank imaging will be presented for these two experiments. In addition, a brief review of how to utilize a 2-D sonar image to generate a 3-D surface of the settled layer within a tank will be discussed.

  12. Deploying perfSONAR-based End-2-End monitoring for production US CMS networking

    SciTech Connect

    Grigoriev, Maxim; Bobyshev, Andrey; Crawford, Matt; DeMar, Phil; Grigaliunas, Vyto; Petravick, Don; /Fermilab

    2007-09-01

    Fermilab is the US Tier-1 Center for CMS data storage and analysis. End-2-End (E2E) circuits are utilized to support high impact data movement into and out of the Tier-1 Center. E2E circuits have been implemented to facilitate the movement of raw experiment data from the Tier-0 Center at CERN, as well as processed data to a number of the US Tier-2 sites. Troubleshooting and monitoring of those circuits presents a significant challenge, since the circuits typically cross multiple research & education networks, each with its own management domain and customized monitoring capabilities. The perfSONAR Monitoring Project was established to facilitate development and deployment of a common monitoring infrastructure across multiple network management domains. Fermilab has deployed perfSONAR across its E2E circuit infrastructure and enhanced the product with several tools that ease the monitoring and management of those circuits. This paper will present the current state of perfSONAR monitoring at Fermilab and detail our experiences using perfSONAR to manage our current E2E circuit infrastructure. We will describe how production network circuits are monitored by perfSONAR E2E Monitoring Points (MPs), and the benefits it has brought to production US CMS networking support.

  13. Enhanced Sidescan-Sonar Imagery, North-Central Long Island Sound

    USGS Publications Warehouse

    McMullen, K.Y.; Poppe, L.J.; Schattgen, P.T.; Doran, E.F.

    2008-01-01

    The U.S. Geological Survey, National Oceanic and Atmospheric Administration (NOAA), and Connecticut Department of Environmental Protection have been working cooperatively to map the sea-floor geology within Long Island Sound. Sidescan-sonar imagery collected during three NOAA hydrographic surveys (H11043, H11044, and H11045) was used to interpret the surficial-sediment distribution and sedimentary environments within the Sound. The original sidescan-sonar imagery generated by NOAA was used to evaluate hazards to navigation, which does not require consistent tonal matching throughout the survey. In order to fully utilize these data for geologic interpretation, artifacts within the imagery, primarily due to sidescan-system settings (for example, gain changes), processing techniques (for example, lack of across-track normalization) and environmental noise (for example, sea state), need to be minimized. Sidescan-sonar imagery from surveys H11043, H11044, and H11045 in north-central Long Island Sound was enhanced by matching the grayscale tones between adjacent sidescan-sonar lines to decrease the patchwork effect caused by numerous artifacts and to provide a more coherent sidescan-sonar image for use in geologic interpretation.

  14. High-Resolution Underwater Mapping Using Side-Scan Sonar.

    PubMed

    Burguera, Antoni; Oliver, Gabriel

    2016-01-01

    The goal of this study is to generate high-resolution sea floor maps using a Side-Scan Sonar(SSS). This is achieved by explicitly taking into account the SSS operation as follows. First, the raw sensor data is corrected by means of a physics-based SSS model. Second, the data is projected to the sea-floor. The errors involved in this projection are thoroughfully analysed. Third, a probabilistic SSS model is defined and used to estimate the probability of each sea-floor region to be observed. This probabilistic information is then used to weight the contribution of each SSS measurement to the map. Because of these models, arbitrary map resolutions can be achieved, even beyond the sensor resolution. Finally, a geometric map building method is presented and combined with the probabilistic approach. The resulting map is composed of two layers. The echo intensity layer holds the most likely echo intensities at each point in the sea-floor. The probabilistic layer contains information about how confident can the user or the higher control layers be about the echo intensity layer data. Experimental results have been conducted in a large subsea region.

  15. Graphical derivations of radar, sonar, and communication signals

    NASA Technical Reports Server (NTRS)

    Altes, R. A.; Titlebaum, E. L.

    1975-01-01

    The designer of a communication system often has knowledge concerning the changes in distance between transmitter and receiver as a function of time. This information can be exploited to reduce multipath interference via proper signal design. A radar or sonar may also have good a priori information about possible target trajectories. Such knowledge can again be used to reduce the receiver's response to clutter (MTI), to enhance signal-to-noise ratio, or to simplify receiver design. There are also situations in which prior knowledge about trajectories is lacking. The system should then utilize a single-filter pair which is insensitive to the effects induced by relative motion between transmitter, receiver, and reflectors. For waveforms with large time-bandwidth products, such as long pulse trains, it is possible to graphically derive signal formats for both situations (trajectory known and unknown). Although the exact form of the signal is sometimes not specified by the graphical procedure, the problem in such cases is reduced to one which has already been solved, i.e., the generation of an impulse equivalent code.

  16. High-Resolution Underwater Mapping Using Side-Scan Sonar

    PubMed Central

    2016-01-01

    The goal of this study is to generate high-resolution sea floor maps using a Side-Scan Sonar(SSS). This is achieved by explicitly taking into account the SSS operation as follows. First, the raw sensor data is corrected by means of a physics-based SSS model. Second, the data is projected to the sea-floor. The errors involved in this projection are thoroughfully analysed. Third, a probabilistic SSS model is defined and used to estimate the probability of each sea-floor region to be observed. This probabilistic information is then used to weight the contribution of each SSS measurement to the map. Because of these models, arbitrary map resolutions can be achieved, even beyond the sensor resolution. Finally, a geometric map building method is presented and combined with the probabilistic approach. The resulting map is composed of two layers. The echo intensity layer holds the most likely echo intensities at each point in the sea-floor. The probabilistic layer contains information about how confident can the user or the higher control layers be about the echo intensity layer data. Experimental results have been conducted in a large subsea region. PMID:26821379

  17. Dolphin and bat sonar: Convergence, divergence, or parallelism

    NASA Astrophysics Data System (ADS)

    Ketten, Darlene R.; Simmons, James; Hubbard, Allyn E.; Mountain, David A.

    2001-05-01

    During the explosive period of mammalian radiation, two groups emerged with highly effective biosonar systems, bats and toothed whales. In the intervening 50 million years, these groups evolutionarily honed their hearing for operation in radically different media. This paper addresses what functional aspects the media influenced in the biosonar receptors of bats versus dolphins by comparing the auditory peripheries of these groups. Data were obtained using thin-section microscopy, CT imaging, and inner-ear models. Inner-ear anatomy is fundamentally similar in these animals, although differences exist in both neural density and distribution in each group. Specialist ears are present in both groups, suggesting at least one odontocete species has cochlear specializations consistent with CF-FM bats, including specialized basilar-membrane regions and high-frequency neural foveal areas. Cochlear specializations in both groups are primarily linked to peak spectra of sonar signals, may expand frequency representation, and may enhance tuning in adjacent ear segments by generating standing wave phenomena. Most differences, such as the soft-tissue external ear analogs in odontocetes, are clearly media driven. Other differences among species within each group are correlated with signal type or habitat complexity. [Work supported by Mellon Foundation; Seaver Institute; ONR.

  18. Bi-static sonar applications of intensity processing.

    PubMed

    Naluai, Nathan K; Lauchle, Gerald C; Gabrielson, Thomas B; Joseph, John H

    2007-04-01

    Acoustic intensity processing of signals from directional sonobuoy acoustic subsystems is used to enhance the detection of submerged bodies in bi-static sonar applications. In some directions, the scattered signals may be completely dominated by the incident blast from the source, depending upon the geometry, making the object undetectable by traditional pressure measurements. Previous theoretical derivations suggest that acoustic vector intensity sensors, and the associated intensity processing, are a potential solution to this problem. Deep water experiments conducted at Lake Pend Oreille in northern Idaho are described. A large, hollow cylindrical body is located between a source and a number of SSQ-53D sonobuoys positioned from 5 to 30 body lengths away from the scattering body. Measurements show changes in the acoustic pressure of less than 0.5 dB when the scattering body is inserted in the field. However, the phase of the acoustic intensity component formed between the acoustic pressure and particle velocity component orthogonal to the direction of incident wave propagation varies by as much as 55 degrees. This metric is shown to be a repeatable and strong indicator of the presence of the scattering body.

  19. Dolphin and bat sonar: Convergence, divergence, or parallelism

    NASA Astrophysics Data System (ADS)

    Ketten, Darlene R.; Simmons, James; Hubbard, Allyn E.; Mountain, David A.

    2004-05-01

    During the explosive period of mammalian radiation, two groups emerged with highly effective biosonar systems, bats and toothed whales. In the intervening 50 million years, these groups evolutionarily honed their hearing for operation in radically different media. This paper addresses what functional aspects the media influenced in the biosonar receptors of bats versus dolphins by comparing the auditory peripheries of these groups. Data were obtained using thin-section microscopy, CT imaging, and inner-ear models. Inner-ear anatomy is fundamentally similar in these animals, although differences exist in both neural density and distribution in each group. Specialist ears are present in both groups, suggesting at least one odontocete species has cochlear specializations consistent with CF-FM bats, including specialized basilar-membrane regions and high-frequency neural foveal areas. Cochlear specializations in both groups are primarily linked to peak spectra of sonar signals, may expand frequency representation, and may enhance tuning in adjacent ear segments by generating standing wave phenomena. Most differences, such as the soft-tissue external ear analogs in odontocetes, are clearly media driven. Other differences among species within each group are correlated with signal type or habitat complexity. [Work supported by Mellon Foundation; Seaver Institute; ONR.

  20. Location and Characterization of Underwater Ordnance using Resonance Scattered Sonar

    NASA Astrophysics Data System (ADS)

    Gritto, R.; Korneev, V. A.

    2009-12-01

    Unexploded ordnance (UXO) present a worldwide hazard in locations of previous military confrontations and at military training facilities. In particular, the presence of unexploded ordinance in coastal regions poses a severe risk that must be addressed before sites can be turned over to the public or coastal areas made available for commercial traffic. Although progress has been made in detecting UXO in underwater areas, there still exists a need for technologies that can detect and locate UXO buried in seafloor sediments and reliably distinguish munitions from clutter. We are investigating a method based on resonance scattering using small data sets in a controlled pond environment. The use of resonance scattering allows for deeper bottom penetration than in the case of the generally used acoustic imaging, because in the former case the wavelengths are longer than the latter. Furthermore, in the resonance scattering regime the geometry is independent of the target orientation. The sonar data sets were acquired during 2006 and 2007 by the Applied Physics Laboratory, University of Washington, at the Surface Warfare Center, Panama City, FL, and included an aluminum cylinder and sphere, as well as artillery shells and mortar rounds buried in the sandy pond bottom. Our results show that resonance scattered waves, although smaller in amplitude than the specular reflected signal, dominate much of the recorded traces in time. These signals can be used to determine the propagation velocities in the pond sediments, to locate the UXO in the subsurface and to characterize the UXO type by its size and filler velocities.

  1. Automated target classification in high resolution dual frequency sonar imagery

    NASA Astrophysics Data System (ADS)

    Aridgides, Tom; Fernández, Manuel

    2007-04-01

    An improved computer-aided-detection / computer-aided-classification (CAD/CAC) processing string has been developed. The classified objects of 2 distinct strings are fused using the classification confidence values and their expansions as features, and using "summing" or log-likelihood-ratio-test (LLRT) based fusion rules. The utility of the overall processing strings and their fusion was demonstrated with new high-resolution dual frequency sonar imagery. Three significant fusion algorithm improvements were made. First, a nonlinear 2nd order (Volterra) feature LLRT fusion algorithm was developed. Second, a Box-Cox nonlinear feature LLRT fusion algorithm was developed. The Box-Cox transformation consists of raising the features to a to-be-determined power. Third, a repeated application of a subset feature selection / feature orthogonalization / Volterra feature LLRT fusion block was utilized. It was shown that cascaded Volterra feature LLRT fusion of the CAD/CAC processing strings outperforms summing, baseline single-stage Volterra and Box-Cox feature LLRT algorithms, yielding significant improvements over the best single CAD/CAC processing string results, and providing the capability to correctly call the majority of targets while maintaining a very low false alarm rate. Additionally, the robustness of cascaded Volterra feature fusion was demonstrated, by showing that the algorithm yields similar performance with the training and test sets.

  2. Testing of a Composite Wavelet Filter to Enhance Automated Target Recognition in SONAR

    NASA Technical Reports Server (NTRS)

    Chiang, Jeffrey N.

    2011-01-01

    Automated Target Recognition (ATR) systems aim to automate target detection, recognition, and tracking. The current project applies a JPL ATR system to low resolution SONAR and camera videos taken from Unmanned Underwater Vehicles (UUVs). These SONAR images are inherently noisy and difficult to interpret, and pictures taken underwater are unreliable due to murkiness and inconsistent lighting. The ATR system breaks target recognition into three stages: 1) Videos of both SONAR and camera footage are broken into frames and preprocessed to enhance images and detect Regions of Interest (ROIs). 2) Features are extracted from these ROIs in preparation for classification. 3) ROIs are classified as true or false positives using a standard Neural Network based on the extracted features. Several preprocessing, feature extraction, and training methods are tested and discussed in this report.

  3. Controlled Sonar Exposure Experiments on Cetaceans in Norwegian Waters: Overview of the 3S-Project.

    PubMed

    Lam, Frans-Peter A; Kvadsheim, Petter H; Miller, Patrick J O; Tyack, Peter L; Ainslie, Michael A; Curé, Charlotte; Kleivane, Lars; Sivle, Lise Doksæter; van Ijsselmuide, Sander P; Visser, Fleur; von Benda-Beckmann, Alexander M; Wensveen, Paul J; Dekeling, René P A

    2016-01-01

    In mitigating the risk of sonar operations, the behavioral response of cetaceans is one of the major knowledge gaps that needs to be addressed. The 3S-Project has conducted a number of controlled exposure experiments with a realistic sonar source in Norwegian waters from 2006 to 2013. In total, the following six target species have been studied: killer, long-finned pilot, sperm, humpback, minke, and northern bottlenose whales. A total of 38 controlled sonar exposures have been conducted on these species. Responses from controlled and repeated exposure runs have been recorded using acoustic and visual observations as well as with electronic tags on the target animal. So far, the first dose-response curves as well as an overview of the scored severity of responses have been revealed. In this paper, an overview is presented of the approach for the study, including the results so far as well as the current status of the ongoing analysis.

  4. Detecting submerged bodies: controlled research using side-scan sonar to detect submerged proxy cadavers.

    PubMed

    Healy, Carrie A; Schultz, John J; Parker, Kenneth; Lowers, Bim

    2015-05-01

    Forensic investigators routinely deploy side-scan sonar for submerged body searches. This study adds to the limited body of literature by undertaking a controlled project to understand how variables affect detection of submerged bodies using side-scan sonar. Research consisted of two phases using small and medium-sized pig (Sus scrofa) carcasses as proxies for human bodies to investigate the effects of terrain, body size, frequency, swath width, and state of decomposition. Results demonstrated that a clear, flat, sandy pond floor terrain was optimal for detection of the target as irregular terrain and/or vegetation are major limitations that can obscure the target. A higher frequency towfish was preferred for small bodies, and a 20 m swath width allowed greater visibility and easier maneuverability of the boat in this environment. Also, the medium-sized carcasses were discernable throughout the 81-day study period, indicating that it is possible to detect bodies undergoing decomposition with side-scan sonar.

  5. Behavioral Response of Reef Fish and Green Sea Turtles to Midfrequency Sonar.

    PubMed

    Watwood, Stephanie L; Iafrate, Joseph D; Reyier, Eric A; Redfoot, William E

    2016-01-01

    There is growing concern over the potential effects of high-intensity sonar on wild fish populations and commercial fisheries. Acoustic telemetry was employed to measure the movements of free-ranging reef fish and sea turtles in Port Canaveral, FL, in response to routine submarine sonar testing. Twenty-five sheepshead (Archosargus probatocephalus), 28 gray snapper (Lutjanus griseus), and 29 green sea turtles (Chelonia mydas) were tagged, with movements monitored for a period of up to 4 months using an array of passive acoustic receivers. Baseline residency was examined for fish and sea turtles before, during, and after the test event. No mortality of tagged fish or sea turtles was evident from the sonar test event. There was a significant increase in the daily residency index for both sheepshead and gray snapper at the testing wharf subsequent to the event. No broad-scale movement from the study site was observed during or immediately after the test.

  6. A Fisheries Application of a Dual-Frequency Identification Sonar Acoustic Camera

    SciTech Connect

    Moursund, Russell A.; Carlson, Thomas J.; Peters, Rock D.

    2003-06-01

    The uses of an acoustic camera in fish passage research at hydropower facilities are being explored by the U.S. Army Corps of Engineers. The Dual-Frequency Identification Sonar (DIDSON) is a high-resolution imaging sonar that obtains near video-quality images for the identification of objects underwater. Developed originally for the Navy by the University of Washington?s Applied Physics Laboratory, it bridges the gap between existing fisheries assessment sonar and optical systems. Traditional fisheries assessment sonars detect targets at long ranges but cannot record the shape of targets. The images within 12 m of this acoustic camera are so clear that one can see fish undulating as they swim and can tell the head from the tail in otherwise zero-visibility water. In the 1.8 MHz high-frequency mode, this system is composed of 96 beams over a 29-degree field of view. This high resolution and a fast frame rate allow the acoustic camera to produce near video-quality images of objects through time. This technology redefines many of the traditional limitations of sonar for fisheries and aquatic ecology. Images can be taken of fish in confined spaces, close to structural or surface boundaries, and in the presence of entrained air. The targets themselves can be visualized in real time. The DIDSON can be used where conventional underwater cameras would be limited in sampling range to < 1 m by low light levels and high turbidity, and where traditional sonar would be limited by the confined sample volume. Results of recent testing at The Dalles Dam, on the lower Columbia River in Oregon, USA, are shown.

  7. Multibeam Sonar Backscatter Data Acquisition and Processing: Guidelines and Recommendations from the GEOHAB Backscatter Working Group

    NASA Astrophysics Data System (ADS)

    Heffron, E.; Lurton, X.; Lamarche, G.; Brown, C.; Lucieer, V.; Rice, G.; Schimel, A.; Weber, T.

    2015-12-01

    Backscatter data acquired with multibeam sonars are now commonly used for the remote geological interpretation of the seabed. The systems hardware, software, and processing methods and tools have grown in numbers and improved over the years, yet many issues linger: there are no standard procedures for acquisition, poor or absent calibration, limited understanding and documentation of processing methods, etc. A workshop organized at the GeoHab (a community of geoscientists and biologists around the topic of marine habitat mapping) annual meeting in 2013 was dedicated to seafloor backscatter data from multibeam sonars and concluded that there was an overwhelming need for better coherence and agreement on the topics of acquisition, processing and interpretation of data. The GeoHab Backscatter Working Group (BSWG) was subsequently created with the purpose of documenting and synthetizing the state-of-the-art in sensors and techniques available today and proposing methods for best practice in the acquisition and processing of backscatter data. Two years later, the resulting document "Backscatter measurements by seafloor-mapping sonars: Guidelines and Recommendations" was completed1. The document provides: An introduction to backscatter measurements by seafloor-mapping sonars; A background on the physical principles of sonar backscatter; A discussion on users' needs from a wide spectrum of community end-users; A review on backscatter measurement; An analysis of best practices in data acquisition; A review of data processing principles with details on present software implementation; and finally A synthesis and key recommendations. This presentation reviews the BSWG mandate, structure, and development of this document. It details the various chapter contents, its recommendations to sonar manufacturers, operators, data processing software developers and end-users and its implication for the marine geology community. 1: Downloadable at https://www.niwa.co.nz/coasts-and-oceans/research-projects/backscatter-measurement-guidelines

  8. Automated detection of submerged navigational obstructions in freshwater impoundments with hull mounted sidescan sonar

    NASA Astrophysics Data System (ADS)

    Morris, Phillip A.

    The prevalence of low-cost side scanning sonar systems mounted on small recreational vessels has created improved opportunities to identify and map submerged navigational hazards in freshwater impoundments. However, these economical sensors also present unique challenges for automated techniques. This research explores related literature in automated sonar imagery processing and mapping technology, proposes and implements a framework derived from these sources, and evaluates the approach with video collected from a recreational grade sonar system. Image analysis techniques including optical character recognition and an unsupervised computer automated detection (CAD) algorithm are employed to extract the transducer GPS coordinates and slant range distance of objects protruding from the lake bottom. The retrieved information is formatted for inclusion into a spatial mapping model. Specific attributes of the sonar sensors are modeled such that probability profiles may be projected onto a three dimensional gridded map. These profiles are computed from multiple points of view as sonar traces crisscross or come near each other. As lake levels fluctuate over time so do the elevation points of view. With each sonar record, the probability of a hazard existing at certain elevations at the respective grid points is updated with Bayesian mechanics. As reinforcing data is collected, the confidence of the map improves. Given a lake's current elevation and a vessel draft, a final generated map can identify areas of the lake that have a high probability of containing hazards that threaten navigation. The approach is implemented in C/C++ utilizing OpenCV, Tesseract OCR, and QGIS open source software and evaluated in a designated test area at Lake Lavon, Collin County, Texas.

  9. Effects of low-frequency naval sonar exposure on three species of fish.

    PubMed

    Halvorsen, Michele B; Zeddies, David G; Chicoine, David; Popper, Arthur N

    2013-08-01

    To address growing concern over the impact of anthropogenic sound on fishes, a series of experiments was conducted that exposed several fish species to high-intensity low-frequency naval sonar. This study extends auditory findings by adding largemouth bass, yellow perch, and channel catfish. No effects on hearing were found in largemouth bass and yellow perch and only small effects in channel catfish (a fish with morphological adaptations for enhanced pressure reception). Together with prior findings, these results suggest limited impact on hearing from high-intensity sonar. Susceptibility may be due to genetic stock, developmental conditions, seasonal variation, and/or buoyancy during exposure.

  10. Underwater simultaneous localization and mapping based on forward-looking sonar

    NASA Astrophysics Data System (ADS)

    Zhang, Tiedong; Zeng, Wenjing; Wan, Lei

    2011-09-01

    A method of underwater simultaneous localization and mapping (SLAM) based on forward-looking sonar was proposed in this paper. Positions of objects were obtained by the forward-looking sonar, and an improved association method based on an ant colony algorithm was introduced to estimate the positions. In order to improve the precision of the positions, the extended Kalman filter (EKF) was adopted. The presented algorithm was tested in a tank, and the maximum estimation error of SLAM gained was 0.25 m. The tests verify that this method can maintain better association efficiency and reduce navigation error.

  11. Using interactions between features on a superdirectional sonar to find wrecks

    NASA Astrophysics Data System (ADS)

    Smith, Roderick A.; Phillips, Susan; Beeston, Paul; Phillips, Pepe

    2001-10-01

    A DERA classifier has been interfaced to a recreational sonar form Echo Pilot to provide a wreck location capability. In normal use, a single forward-looking beam plots the seabed contour by using super-directional techniques. The sonar monitors the amplitude of received echoes, and when this exceeds a given threshold it computes the inclination corresponding to the echo. The classifier uses the original data streams, and converts them to feature values on each ping; new classes of features have been developed to augment those usually used on A-scans.

  12. More than the Bottom: Multibeam Sonars and Water-column Imaging (Invited)

    NASA Astrophysics Data System (ADS)

    Mayer, L. A.; Weber, T.; Gardner, J. V.; Malik, M.; Doucet, M.; Beaudoin, J.

    2010-12-01

    The past ten years have seen remarkable advances in our ability to rapidly and accurately map the seafloor. Improvements in sonar design and signal processing have dramatically increased both the spatial and temporal resolution of seafloor mapping systems as well as provided the opportunity to extract information about seafloor character through the concomitant mapping of seafloor backscatter. The latest generation of multibeam sonars, however, can now provide acoustic returns from the water-column as well as from the seafloor. When combined with powerful new visualization tools, the ability to acoustically map large volumes of the water-column opens up vast new areas of application for multibeam sonar data. When applied to the most traditional use of multibeam sonar data (seafloor mapping in support of safe navigation), water-column data afford the opportunity to see small, high-standing targets (like ship’s masts) and offer a powerful tool for critically needed, least-depth detection. Water-column data collected from multibeam sonars also provide numerous opportunities for fisheries research ranging from qualitative descriptions of fish school behavior and vessel avoidance studies (the systems can make measurements well beyond the limited, normal-incidence view of traditional fisheries sonars), to the eventual quantitative measurements of volume backscatter (as systems become more calibrated). Increases in system bandwidth will also open opportunities for target identification studies. With increased bandwith will also come the potential for tuning the systems for the mapping of watermass boundaries, offering a powerful tool for a range of physical oceanographic applications. Finally, the ability to map the water-column has great potential for quantifying the flux of methane into the ocean from natural (and un-natural) seeps. Water-column mapping has already proven a valuable asset in monitoring the Deepwater Horizon well-site for potential blow-outs or gas

  13. Flying in silence: Echolocating bats cease vocalizing to avoid sonar jamming

    PubMed Central

    Chiu, Chen; Xian, Wei; Moss, Cynthia F.

    2008-01-01

    Although it has been recognized that echolocating bats may experience jamming from the signals of conspecifics, research on this problem has focused exclusively on time-frequency adjustments in the emitted signals to minimize interference. Here, we report a surprising new strategy used by bats to avoid interference, namely silence. In a quantitative study of flight and vocal behavior of the big brown bat (Eptesicus fuscus), we discovered that the bat spends considerable time in silence when flying with conspecifics. Silent behavior, defined here as at least one bat in a pair ceasing vocalization for more than 0.2 s (200 ms), occurred as much as 76% of the time (mean of 40% across 7 pairs) when their separation was shorter than 1 m, but only 0.08% when a single bat flew alone. Spatial separation, heading direction, and similarity in call design of paired bats were related to the prevalence of this silent behavior. Our data suggest that the bat uses silence as a strategy to avoid interference from sonar vocalizations of its neighbor, while listening to conspecific-generated acoustic signals to guide orientation. Based on previous neurophysiological studies of the bat's auditory midbrain, we hypothesize that environmental sounds (including vocalizations produced by other bats) and active echolocation evoke neural activity in different populations of neurons. Our findings offer compelling evidence that the echolocating bat switches between active and passive sensing to cope with a complex acoustic environment, and these results hold broad implications for research on navigation and communication throughout the animal kingdom. PMID:18725624

  14. Advanced piezoelectric single crystal based transducers for naval sonar applications

    NASA Astrophysics Data System (ADS)

    Snook, Kevin A.; Rehrig, Paul W.; Hackenberger, Wesley S.; Jiang, Xiaoning; Meyer, Richard J., Jr.; Markley, Douglas

    2006-03-01

    Transducers incorporating single crystal piezoelectric Pb(Mg 1/3Nb 2/3) x-1Ti xO 3 (PMN-PT) exhibit significant advantages over ceramic piezoelectrics such as PZT, including both high electromechanical coupling (k 33 > 90%) and piezoelectric coefficients (d 33 > 2000 pC/N). Conventional <001> orientation gives inherently larger bandwidth and output power than PZT ceramics, however, the anisotropy of the crystal also allows for tailoring of the performance by orienting the crystal along different crystallographic axes. This attribute combined with composition refinements can be used to improve thermal or mechanical stability, which is important in high power, high duty cycle sonar applications. By utilizing the "31" resonance mode, the high power performance of PMN-PT can be improved over traditional "33" mode single crystal transducers, due to an improved aspect ratio. Utilizing novel geometries, effective piezoelectric constants of -600 pC/N to -1200 pC/N have been measured. The phase transition point induced by temperature, pre-stress or field is close to that in the "33" mode, and since the prestress is applied perpendicular to the poling direction in "31" mode elements, they exhibit lower loss and can therefore be driven harder. The high power characteristics of tonpilz transducers can also be affected by the composition of the PMN-PT crystal. TRS modified the composition of PMN-PT to improve the thermal stability of the material, while keeping the loss as low as possible. Three dimensional modeling shows that the useable bandwidth of these novel compositions nearly equals that of conventional PMN-PT. A decrease in the source level of up to 6 dB was calculated, which can be compensated for by the higher drive voltages possible.

  15. "Near-bottom sonar mapping along the Eastern Lau Spreading Center and Valu Fa Ridge"

    NASA Astrophysics Data System (ADS)

    Sleeper, J. D.; Martinez, F.; Edwards, M.; Dunn, R.; Baker, E. T.

    2009-12-01

    We present results from high resolution sidescan sonar mapping at the Ridge 2000 Lau Integrated Studies Site, a back-arc spreading center in the Southwest Pacific. The survey covered segments of the Eastern Lau Spreading Center (ELSC) and Valu Fa Ridge (VFR), which exhibit strong contrasts in geologic and geophysical characteristics, including variations in ridge morphology, volcanic and tectonic structures, lava composition and texture, magma production, and spreading rate. The bulk of the data were collected in 2008 aboard R/V Kilo Moana (KM0804), using the deep-towed IMI120 (DSL120A) sonar, with an array of miniature autonomous plume recorder's (MAPR's) tethered to the tow cable to detect hydrothermal plume signatures in the water column. The ELSC survey covered an area ~10 km wide by 100 km long centered on the spreading axis, with tracks spaced ~1 km apart, but as close as ~500 m in the vicinity of the ABE hydrothermal vent field, and also included the Tow Cam and Kilo Moana vent fields. The VFR survey covered a ~5 km wide by 100 km long area with ~700 m-spaced tracks, including the Vai Lili, Mariner, and Tui Malila vent sites. The IMI120 has a resolution of ~1-2 meters, giving the first detailed view of the on- and off-axis structures in the two focus regions. Navigational corrections to the sidescan data were made through feature-matching between the deep-towed data and a lower resolution background ship bathymetry grid, using software developed by the Hawaiian Mapping and Research Group. Background bathymetry and lower resolution (~100 m) sidescan data were compiled from previous cruises on R/V Kilo Moana, and an early-2009 seismic survey on R/V Marcus G. Langseth (L-SCAN). Hydrothermal plume data collected with the MAPR's are coregistered with the deep-towed sidescan data to illuminate correlations between seafloor structures and plume signatures. The axis of the VFR in the south forms a peaked ridge, inflated by abundant melt supply, and draped with

  16. Making Accurate Topographic Maps of the Schoolyard Using Ideas and Techniques Learned and Adapted from Multi-beam Sonar Mapping of the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Fuerst, S. I.; Roberts, J. D.

    2010-12-01

    Having participated in a University of Rhode Island Project Armada expedition to join the University of New Hampshire Center for Coastal and Oceanographic Studies in making multi-beam sonar contour maps of the Arctic Ocean floor, I was able to bring the principles learned from this trip to my earth science high school students and create a project in our "mapping the earth" unit. Students learn basic surveying techniques and create authentic, accurately detailed topographic maps of the schoolyard. Models of their maps are then constructed of either Styrofoam or wood which enables them to make the transition from a 2-dimensional map to a 3-dimensional representation. Even though our maps are created using sticks, line levels, compasses and GPS, the scientific concepts of using location and elevation data to draw contour lines are identical to those used in underwater mapping. Once the students understand the science in mapping and creating contour maps to scale on graph paper by hand, they are able to easily relate this knowledge to what I was doing onboard ship using multi-beam sonar and computer mapping programs. We would like to share with you the lab and techniques that we have developed to make this activity possible with minimal materials and simple technology. As a background extension, it is also possible to replicate sonar measurements using an aquarium, food coloring, and a surface grid to map the topography of a teacher created landscape on the aquarium bottom. Earth Science students using simple tools to accurately map the topography of the school grounds

  17. Sonar Recognition Training: An Investigation of Whole VS. Part and Analytic VS. Synthetic Procedures.

    ERIC Educational Resources Information Center

    Annett, John

    An experienced person, in such tasks as sonar detection and recognition, has a considerable superiority over a machine recognition system in auditory pattern recognition. However, people require extensive exposure to auditory patterns before achieving a high level of performance. In an attempt to discover a method of training people to recognize…

  18. Case Study of Using Resources about Sonar Operators To Teach Instructional Design.

    ERIC Educational Resources Information Center

    Mclellan, Hilary

    1993-01-01

    Describes a fictional account of the work of a submarine sonar operator ("The Hunt for Red October" by Tom Clancy) that captures the practitioner in a complex real-world work context featuring sophisticated electronic technologies. Describes how fiction can be adapted for and used as a basis for instructional design students to explore…

  19. 28. SONAR CONTROL ROOM FORWARD LOOKING AFT SHOWING AN/SQS23G ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. SONAR CONTROL ROOM - FORWARD LOOKING AFT SHOWING AN/SQS-23G DETECTING-RANGING SET, MARK & CONTROL PANEL, CAN-55134 RECORDER, SPEED INDICATOR, VARIOUS ALARMS AND INTERNAL COMMUNICATION CIRCUITS. - U.S.S. HORNET, Puget Sound Naval Shipyard, Sinclair Inlet, Bremerton, Kitsap County, WA

  20. An investigation of acoustic beam patterns for the sonar localization problem using a beam based method.

    PubMed

    Guarato, Francesco; Windmill, James; Gachagan, Anthony; Harvey, Gerald

    2013-06-01

    Target localization can be accomplished through an ultrasonic sonar system equipped with an emitter and two receivers. Time of flight of the sonar echoes allows the calculation of the distance of the target. The orientation can be estimated from knowledge of the beam pattern of the receivers and the ratio, in the frequency domain, between the emitted and the received signals after compensation for distance effects and air absorption. The localization method is described and, as its performance strongly depends on the beam pattern, the search of the most appropriate sonar receiver in order to ensure the highest accuracy of target orientation estimations is developed in this paper. The structure designs considered are inspired by the ear shapes of some bat species. Parameters like flare rate, truncation angle, and tragus are considered in the design of the receiver structures. Simulations of the localization method allow us to state which combination of those parameters could provide the best real world implementation. Simulation results show the estimates of target orientations are, in the worst case, 2° with SNR = 50 dB using the receiver structure chosen for a potential practical implementation of a sonar system.

  1. Object representation for multi-beam sonar image using local higher-order statistics

    NASA Astrophysics Data System (ADS)

    Li, Haisen; Gao, Jue; Du, Weidong; Zhou, Tian; Xu, Chao; Chen, Baowei

    2017-01-01

    Multi-beam sonar imaging has been widely used in various underwater tasks such as object recognition and object tracking. Problems remain, however, when the sonar images are characterized by low signal-to-noise ratio, low resolution, and amplitude alterations due to viewpoint changes. This paper investigates the capacity of local higher-order statistics (HOS) to represent objects in multi-beam sonar images. The Weibull distribution has been used for modeling the background of the image. Local HOS involving skewness is estimated using a sliding computational window, thus generating the local skewness image of which a square structure is associated with a potential object. The ability of object representation with different signal-to-noise ratio (SNR) between object and background is analyzed, and the choice of the computational window size is discussed. In the case of the object with high SNR, a novel algorithm based on background estimation is proposed to reduce side lobe and retain object regions. The performance of object representation has been evaluated using real data that provided encouraging results in the case of the object with low amplitude, high side lobes, or large fluctuant amplitude. In conclusion, local HOS provides more reliable and stable information relating to the potential object and improves the object representation in multi-beam sonar image.

  2. Tight coordination of aerial flight maneuvers and sonar call production in insectivorous bats.

    PubMed

    Falk, Benjamin; Kasnadi, Joseph; Moss, Cynthia F

    2015-11-01

    Echolocating bats face the challenge of coordinating flight kinematics with the production of echolocation signals used to guide navigation. Previous studies of bat flight have focused on kinematics of fruit and nectar-feeding bats, often in wind tunnels with limited maneuvering, and without analysis of echolocation behavior. In this study, we engaged insectivorous big brown bats in a task requiring simultaneous turning and climbing flight, and used synchronized high-speed motion-tracking cameras and audio recordings to quantify the animals' coordination of wing kinematics and echolocation. Bats varied flight speed, turn rate, climb rate and wingbeat rate as they navigated around obstacles, and they adapted their sonar signals in patterning, duration and frequency in relation to the timing of flight maneuvers. We found that bats timed the emission of sonar calls with the upstroke phase of the wingbeat cycle in straight flight, and that this relationship changed when bats turned to navigate obstacles. We also characterized the unsteadiness of climbing and turning flight, as well as the relationship between speed and kinematic parameters. Adaptations in the bats' echolocation call frequency suggest changes in beam width and sonar field of view in relation to obstacles and flight behavior. By characterizing flight and sonar behaviors in an insectivorous bat species, we find evidence of exquisitely tight coordination of sensory and motor systems for obstacle navigation and insect capture.

  3. Modeling effectiveness of gradual increases in source level to mitigate effects of sonar on marine mammals.

    PubMed

    Von Benda-Beckmann, Alexander M; Wensveen, Paul J; Kvadsheim, Petter H; Lam, Frans-Peter A; Miller, Patrick J O; Tyack, Peter L; Ainslie, Michael A

    2014-02-01

    Ramp-up or soft-start procedures (i.e., gradual increase in the source level) are used to mitigate the effect of sonar sound on marine mammals, although no one to date has tested whether ramp-up procedures are effective at reducing the effect of sound on marine mammals. We investigated the effectiveness of ramp-up procedures in reducing the area within which changes in hearing thresholds can occur. We modeled the level of sound killer whales (Orcinus orca) were exposed to from a generic sonar operation preceded by different ramp-up schemes. In our model, ramp-up procedures reduced the risk of killer whales receiving sounds of sufficient intensity to affect their hearing. The effectiveness of the ramp-up procedure depended strongly on the assumed response threshold and differed with ramp-up duration, although extending the duration of the ramp up beyond 5 min did not add much to its predicted mitigating effect. The main factors that limited effectiveness of ramp up in a typical antisubmarine warfare scenario were high source level, rapid moving sonar source, and long silences between consecutive sonar transmissions. Our exposure modeling approach can be used to evaluate and optimize mitigation procedures.

  4. The Sonar Simulation Toolset, Release 4.1: Science, Mathematics and Algorithms

    DTIC Science & Technology

    2005-03-01

    like Mathematica [Mathematica] or Matlab [Mat- lab], or public-domain tools like Octave [Octave] or Gnuplot [ Gnuplot ], specialized tools like the SIO... Gnuplot ] T. Williams and C. Kelley, gnuplot , http://www.gnuplot.info/. 2.2 [Goddard 1986] R. P. Goddard, “REVGEN-4 High-Fidelity Simulation of Sonar

  5. Model-based approach to the detection and classification of mines in sidescan sonar.

    PubMed

    Reed, Scott; Petillot, Yvan; Bell, Judith

    2004-01-10

    This paper presents a model-based approach to mine detection and classification by use of sidescan sonar. Advances in autonomous underwater vehicle technology have increased the interest in automatic target recognition systems in an effort to automate a process that is currently carried out by a human operator. Current automated systems generally require training and thus produce poor results when the test data set is different from the training set. This has led to research into unsupervised systems, which are able to cope with the large variability in conditions and terrains seen in sidescan imagery. The system presented in this paper first detects possible minelike objects using a Markov random field model, which operates well on noisy images, such as sidescan, and allows a priori information to be included through the use of priors. The highlight and shadow regions of the object are then extracted with a cooperating statistical snake, which assumes these regions are statistically separate from the background. Finally, a classification decision is made using Dempster-Shafer theory, where the extracted features are compared with synthetic realizations generated with a sidescan sonar simulator model. Results for the entire process are shown on real sidescan sonar data. Similarities between the sidescan sonar and synthetic aperture radar (SAR) imaging processes ensure that the approach outlined here could be made applied to SAR image analysis.

  6. Estimation and Correction of Geometric Distortions in Side-Scan Sonar Images

    DTIC Science & Technology

    1990-03-01

    Dissertation Funding was provided by the Conselho Nacional de Desinvolvemento Cientifico e Tecnologico (CNPq), an agency of the Government of the Federative...in the world market from the beginning. Notable examples of side- scan sonars developed by scientific institutions in the United States are the SeaMARC

  7. Tight coordination of aerial flight maneuvers and sonar call production in insectivorous bats

    PubMed Central

    Falk, Benjamin; Kasnadi, Joseph; Moss, Cynthia F.

    2015-01-01

    ABSTRACT Echolocating bats face the challenge of coordinating flight kinematics with the production of echolocation signals used to guide navigation. Previous studies of bat flight have focused on kinematics of fruit and nectar-feeding bats, often in wind tunnels with limited maneuvering, and without analysis of echolocation behavior. In this study, we engaged insectivorous big brown bats in a task requiring simultaneous turning and climbing flight, and used synchronized high-speed motion-tracking cameras and audio recordings to quantify the animals' coordination of wing kinematics and echolocation. Bats varied flight speed, turn rate, climb rate and wingbeat rate as they navigated around obstacles, and they adapted their sonar signals in patterning, duration and frequency in relation to the timing of flight maneuvers. We found that bats timed the emission of sonar calls with the upstroke phase of the wingbeat cycle in straight flight, and that this relationship changed when bats turned to navigate obstacles. We also characterized the unsteadiness of climbing and turning flight, as well as the relationship between speed and kinematic parameters. Adaptations in the bats' echolocation call frequency suggest changes in beam width and sonar field of view in relation to obstacles and flight behavior. By characterizing flight and sonar behaviors in an insectivorous bat species, we find evidence of exquisitely tight coordination of sensory and motor systems for obstacle navigation and insect capture. PMID:26582935

  8. EFFECTS OF GREEN MACROALGAE ON CLASSIFICATION OF SEAGRASS IN SIDE SCAN SONAR IMAGERY

    EPA Science Inventory

    High resolution maps of seagrass beds are useful for monitoring estuarine condition, managing fish habitats, and modeling estuarine processes. Side scan sonar (SSS) is one method for producing spatially accurate seagrass maps, although it has not been used widely. Our team rece...

  9. Behavioral Response of Dolphins to Signals Simulating Mid-Frequency Sonar

    DTIC Science & Technology

    2011-09-30

    similar to tactical sonar signals; (2) apply a scoring analysis to qualitative descriptors of the observed responses; (3) calculate a behavioral dose ... response function (DRF) for delphinid and otariid species exposed to mid-frequency signals; (4) record heart rate on a subset of the dolphins and sea

  10. Bounding the error on bottom estimation for multi-angle swath bathymetry sonar

    NASA Astrophysics Data System (ADS)

    Mullins, Geoff K.; Bird, John S.

    2005-04-01

    With the recent introduction of multi-angle swath bathymetry (MASB) sonar to the commercial marketplace (e.g., Benthos Inc., C3D sonar, 2004), additions must be made to the current sonar lexicon. The correct interpretation of measurements made with MASB sonar, which uses filled transducer arrays to compute angle-of-arrival information (AOA) from backscattered signal, is essential not only for mapping, but for applications such as statistical bottom classification. In this paper it is shown that aside from uncorrelated channel to channel noise, there exists a tradeoff between effects that govern the error bounds on bottom estimation for surfaces having shallow grazing angle and surfaces distributed along a radial arc centered at the transducer. In the first case, as the bottom aligns with the radial direction to the receiver, footprint shift and shallow grazing angle effects dominate the uncertainty in physical bottom position (surface aligns along a single AOA). Alternatively, if signal from a radial arc arrives, a single AOA is usually estimated (not necessarily at the average location of the surface). Through theoretical treatment, simulation, and field measurements, the aforementioned factors affecting MASB bottom mapping are examined. [Work supported by NSERC.

  11. A Predictive Task Network Model for Estimating the Effectiveness of Decision Aids for Sonar Operators

    DTIC Science & Technology

    2006-01-01

    METHOD 2.1 Building the model Using existing task analyses of navy sonar systems (Matthews, Greenley and Webb, 1991) and with the assistance of...Critical Operator Tasks. DRDC Toronto Report # CR-2003-131 Matthews, M.L., Greenley , M. and Webb, R.D.G (1991). Presentation of Information from Towed

  12. 3S2: Behavioral Response Studies of Cetaceans to Navy Sonar Signals in Norwegian Waters

    DTIC Science & Technology

    2015-09-30

    the 1-2 kHz sonar exposure with a tagged minke whale. Data in the top 4 panels were derived from observations from the trackboat (‘ MOB ’). ‘Direction... MOB ’ refers to the direction of animal movement, while ‘Directness MOB ’ refers to the directness of the track from 0 (circular movement) to 1.0

  13. Final report of DOE project "Detection, Localization and Diagnosis of Performance Problems Using PerfSONAR"

    SciTech Connect

    Dovrolis, Konstantinos

    2014-04-15

    We present the development of a middleware service, called Pythia, that is able to detect, localize, and diagnose performance problems in the network paths that interconnect research sites that are of interest to DOE. The proposed service can analyze perfSONAR data collected from all participating sites.

  14. Shallow water benthic imaging and substrate characterization using recreational-grade sidescan-sonar

    USGS Publications Warehouse

    Buscombe, Daniel D.

    2017-01-01

    In recent years, lightweight, inexpensive, vessel-mounted ‘recreational grade’ sonar systems have rapidly grown in popularity among aquatic scientists, for swath imaging of benthic substrates. To promote an ongoing ‘democratization’ of acoustical imaging of shallow water environments, methods to carry out geometric and radiometric correction and georectification of sonar echograms are presented, based on simplified models for sonar-target geometry and acoustic backscattering and attenuation in shallow water. Procedures are described for automated removal of the acoustic shadows, identification of bed-water interface for situations when the water is too turbid or turbulent for reliable depth echosounding, and for automated bed substrate classification based on singlebeam full-waveform analysis. These methods are encoded in an open-source and freely-available software package, which should further facilitate use of recreational-grade sidescan sonar, in a fully automated and objective manner. The sequential correction, mapping, and analysis steps are demonstrated using a data set from a shallow freshwater environment.

  15. Applications of Fresnel-Kirchhoff diffraction theory in the analysis of human-motion Doppler sonar grams.

    PubMed

    Bradley, Marshall; Sabatier, James M

    2010-11-01

    Observed human-gait features in Doppler sonar grams are explained by using the Boulic-Thalmann (BT) model to predict joint angle time histories and the temporal displacements of the body center of mass. Body segments are represented as ellipsoids. Temporally dependent velocities at the proximal and distal end of key body segments are determined from BT. Doppler sonar grams are computed by mapping velocity-time dependent spectral acoustic-cross sections for the body segments onto time-velocity space, mimicking the Short Time Fourier Transform used in the Doppler sonar processing. Comparisons to measured data indicate that dominant returns come from trunk, thigh and lower leg.

  16. Sonar backscatter differentiation of dominant macrohabitat types in a hydrothermal vent field.

    PubMed

    Durand, Sébastien; Legendre, Pierre; Juniper, S Kim

    2006-08-01

    Over the past 20 years, sonar remote sensing has opened ways of acquiring new spatial information on seafloor habitat and ecosystem properties. While some researchers are presently working to improve sonar methods so that broad-scale high-definition surveys can be effectively conducted for management purposes, others are trying to use these surveying techniques in more local areas. Because ecosystem management is scale-dependent, there is a need to acquire spatiotemporal knowledge over various scales to bridge the gap between already-acquired point-source data and information available at broader scales. Using a 675-kHz single-pencil-beam sonar mounted on the remotely operated vehicle ROPOS, 2200 m deep on the Juan de Fuca Ridge, East Pacific Rise, five dominant habitat types located in a hydrothermal vent field were identified and characterized by their sonar signatures. The data, collected at different altitudes from 1 to 10 m above the seafloor, were depth-normalized. We compared three ways of handling the echoes embedded in the backscatters to detect and differentiate the five habitat types; we examined the influence of footprint size on the discrimination capacity of the three methods; and we identified key variables, derived from echoes that characterize each habitat type. The first method used a set of variables describing echo shapes, and the second method used as variables the power intensity values found within the echoes, whereas the last method combined all these variables. Canonical discriminant analysis was used to discriminate among the five habitat types using the three methods. The discriminant models were constructed using 70% of the data while the remaining 30% were used for validation. The results showed that footprints 20-30 cm in diameter included a sufficient amount of spatial variation to make the sonar signatures sensitive to the habitat types, producing on average 82% correct classification. Smaller footprints produced lower percentages of

  17. Optimal Predator Risk Assessment by the Sonar-Jamming Arctiine Moth Bertholdia trigona

    PubMed Central

    Corcoran, Aaron J.; Wagner, Ryan D.; Conner, William E.

    2013-01-01

    Nearly all animals face a tradeoff between seeking food and mates and avoiding predation. Optimal escape theory holds that an animal confronted with a predator should only flee when benefits of flight (increased survival) outweigh the costs (energetic costs, lost foraging time, etc.). We propose a model for prey risk assessment based on the predator's stage of attack. Risk level should increase rapidly from when the predator detects the prey to when it commits to the attack. We tested this hypothesis using a predator – the echolocating bat – whose active biosonar reveals its stage of attack. We used a prey defense – clicking used for sonar jamming by the tiger moth Bertholdia trigona– that can be readily studied in the field and laboratory and is enacted simultaneously with evasive flight. We predicted that prey employ defenses soon after being detected and targeted, and that prey defensive thresholds discriminate between legitimate predatory threats and false threats where a nearby prey is attacked. Laboratory and field experiments using playbacks of ultrasound signals and naturally behaving bats, respectively, confirmed our predictions. Moths clicked soon after bats detected and targeted them. Also, B. trigona clicking thresholds closely matched predicted optimal thresholds for discriminating legitimate and false predator threats for bats using search and approach phase echolocation – the period when bats are searching for and assessing prey. To our knowledge, this is the first quantitative study to correlate the sensory stimuli that trigger defensive behaviors with measurements of signals provided by predators during natural attacks in the field. We propose theoretical models for explaining prey risk assessment depending on the availability of cues that reveal a predator's stage of attack. PMID:23671686

  18. Geomorphic features off southern California as seen by GLORIA side-scan sonar system

    SciTech Connect

    Edwards, B.D.; Field, M.E.; Carlson, P.R.; Kenyon, N.H.

    1985-02-01

    Approximately 165,000 km/sup 2/ of the sea floor off southern California was mapped during May 1984, as part of a USGS/IOS cooperative program to study the newly proclaimed Exclusive Economic Zone (EEZ) of the US Pacific margin. The area was insonified using the Geological Long-Range Inclined Asdic (GLORIA), a long-range side-scan sonar system. Images were corrected for water-column velocity anomalies, for along-track distortions caused by acoustic ray travel paths. A photomosaic of the overlapping sonographs has been compiled at a scale of 1:375,000. The basins of the inner California continental borderland are characterized by both sinuous channel and fan complexes and by feathery acoustic patterns indicating active sediment transport. In contrast, outer borderland basins appear to be more sediment starved, exhibit large areas of sediment failure, and show significant structural influence. West of Patton Escarpment, the sonographs are dominated by acoustic patterns showing volcanic ridges and seamounts and by deposits of the Monterey and Arguello fans. Arguello fan, for example, exhibits multiple sinuous channels that have transported sediment 60 km south from the canyon mouth. These channels coalesce into a single 100-km long, westward-meandering channel that terminates in a 600-m deep box canyon. A zone of sediment failure is identifiable on the north levee of an upper fan channel. Tectonic trends associated with oceanic basement are highlighted by the terminus of the west-trending Murray Fracture Zone and by the prevailing northeast trend of volcanic ridge and seamount chains.

  19. Groups of bats improve sonar efficiency through mutual suppression of pulse emissions.

    PubMed

    Jarvis, Jenna; Jackson, William; Smotherman, Michael

    2013-01-01

    How bats adapt their sonar behavior to accommodate the noisiness of a crowded day roost is a mystery. Some bats change their pulse acoustics to enhance the distinction between theirs and another bat's echoes, but additional mechanisms are needed to explain the bat sonar system's exceptional resilience to jamming by conspecifics. Variable pulse repetition rate strategies offer one potential solution to this dynamic problem, but precisely how changes in pulse rate could improve sonar performance in social settings is unclear. Here we show that bats decrease their emission rates as population density increases, following a pattern that reflects a cumulative mutual suppression of each other's pulse emissions. Playback of artificially-generated echolocation pulses similarly slowed emission rates, demonstrating that suppression was mediated by hearing the pulses of other bats. Slower emission rates did not support an antiphonal emission strategy but did reduce the relative proportion of emitted pulses that overlapped with another bat's emissions, reducing the relative rate of mutual interference. The prevalence of acoustic interferences occurring amongst bats was empirically determined to be a linear function of population density and mean emission rates. Consequently as group size increased, small reductions in emission rates spread across the group partially mitigated the increase in interference rate. Drawing on lessons learned from communications networking theory we show how modest decreases in pulse emission rates can significantly increase the net information throughput of the shared acoustic space, thereby improving sonar efficiency for all individuals in a group. We propose that an automated acoustic suppression of pulse emissions triggered by bats hearing each other's emissions dynamically optimizes sonar efficiency for the entire group.

  20. Side-scan sonar mapping: Pseudo-real-time processing and mosaicking techniques

    SciTech Connect

    Danforth, W.W.; Schwab, W.C.; O'Brien, T.F. ); Karl, H. )

    1990-05-01

    The US Geological Survey (USGS) surveyed 1,000 km{sup 2} of the continental shelf off San Francisco during a 17-day cruise, using a 120-kHz side-scan sonar system, and produced a digitally processed sonar mosaic of the survey area. The data were processed and mosaicked in real time using software developed at the Lamont-Doherty Geological Observatory and modified by the USGS, a substantial task due to the enormous amount of data produced by high-resolution side-scan systems. Approximately 33 megabytes of data were acquired every 1.5 hr. The real-time sonar images were displayed on a PC-based workstation and the data were transferred to a UNIX minicomputer where the sonar images were slant-range corrected, enhanced using an averaging method of desampling and a linear-contrast stretch, merged with navigation, geographically oriented at a user-selected scale, and finally output to a thermal printer. The hard-copy output was then used to construct a mosaic of the survey area. The final product of this technique is a UTM-projected map-mosaic of sea-floor backscatter variations, which could be used, for example, to locate appropriate sites for sediment sampling to ground truth the sonar imagery while still at sea. More importantly, reconnaissance surveys of this type allow for the analysis and interpretation of the mosaic during a cruise, thus greatly reducing the preparation time needed for planning follow-up studies of a particular area.

  1. Time-series measurements of hydrothermal plume volume flux with imaging sonar

    NASA Astrophysics Data System (ADS)

    Xu, G.; Jackson, D. R.; Bemis, K. G.; Rona, P. A.

    2012-12-01

    COVIS (Cabled Observatory Vent Imaging Sonar) is an innovative sonar system designed to quantitatively monitor the outputs of deep-sea hydrothermal vent clusters for both high-temperature focused vents and diffuse flows. In September 2010, COVIS was connected to the NEPTUNE Canada underwater ocean observatory network (http://www.NEPTUNEcanada.ca) at the Grotto vent cluster at the Main Endeavour Field on the Endeavour Segment of the Juan de Fuca Ridge. Since then, COVIS has been monitoring the hydrothermal plumes above Grotto by transmitting high-frequency (400 kHz), pulsed acoustic waves towards the plumes and recording the backscattered signals from each pulse, except for a one-year hiatus due to the power-off of the NEPTUNE Canada network between November 2010 and September 2011. The received backscatter signals are transmitted via the NEPTUNE Canada network to the land-based servers in real time, where a combination of automatic and manual data analyses produces a plume volume-flux and flow-rate time series using both the intensity and Doppler shift of the backscatter signals. The initial 30-day time series (Sep-Oct 2010) was presented in AGU Fall meeting, 2011. Evident short-term temporal variations (< 2 days) have been observed, which indicates significant interaction between the plume and the ambient tidal current oscillations. To further investigate such interaction and capture long-term patterns of the system, we present a 10-month time series (since the resumption of COVIS in September 2011 until present) of the volume flux and flow rate of the plume discharging from the North Tower of Grotto. The new time series, with a 3-hour sampling rate and long duration, can reveal the variations of the plume on a wide range of time scales (< 2 days ~ months). Compared with its predecessor, the new time series provides a better chance to capture the episodic events (e.g. geologically driven), low-frequency periodic (e.g. seasonal) oscillations, and long-term trend in

  2. Archive of side scan sonar and swath bathymetry data collected during USGS cruise 10CCT01 offshore of Cat Island, Gulf Islands National Seashore, Mississippi, March 2010

    USGS Publications Warehouse

    DeWitt, Nancy T.; Flocks, James G.; Pfeiffer, William R.; Wiese, Dana S.

    2010-01-01

    In March of 2010, the U.S. Geological Survey (USGS) conducted geophysical surveys east of Cat Island, Mississippi (fig. 1). The efforts were part of the USGS Gulf of Mexico Science Coordination partnership with the U.S. Army Corps of Engineers (USACE) to assist the Mississippi Coastal Improvements Program (MsCIP) and the Northern Gulf of Mexico (NGOM) Ecosystem Change and Hazards Susceptibility Project by mapping the shallow geological stratigraphic framework of the Mississippi Barrier Island Complex. These geophysical surveys will provide the data necessary for scientists to define, interpret, and provide baseline bathymetry and seafloor habitat for this area and to aid scientists in predicting future geomorpholocial changes of the islands with respect to climate change, storm impact, and sea-level rise. Furthermore, these data will provide information for barrier island restoration, particularly in Camille Cut, and provide protection for the historical Fort Massachusetts. For more information refer to http://ngom.usgs.gov/gomsc/mscip/index.html. This report serves as an archive of the processed swath bathymetry and side scan sonar data (SSS). Data products herein include gridded and interpolated surfaces, surface images, and x,y,z data products for both swath bathymetry and side scan sonar imagery. Additional files include trackline maps, navigation files, GIS files, Field Activity Collection System (FACS) logs, and formal FGDC metadata. Scanned images of the handwritten FACS logs and digital FACS logs are also provided as PDF files. Refer to the Acronyms page for expansion of acronyms and abbreviations used in this report or hold the cursor over an acronym for a pop-up explanation. The USGS St. Petersburg Coastal and Marine Science Center assigns a unique identifier to each cruise or field activity. For example, 10CCT01 tells us the data were collected in 2010 for the Coastal Change and Transport (CCT) study and the data were collected during the first field

  3. Sidescan Sonar Imagery of the Escanaba Trough, Southern Gorda Ridge, Offshore Northern California

    USGS Publications Warehouse

    Ross, Stephanie L.; Zierenberg, Robert A.

    2009-01-01

    This map features sidescan imagery of the northern Escanaba (NESCA) site at the Escanaba Trough, southern Gorda Ridge, offshore northern California. The Escanaba Trough, a largely sediment-covered seafloor spreading center, contains at least six large massive sulfide deposits. It is a slow spreading center (2.5 cm/yr) with axial depths locally exceeding 3,300 m. Discrete igneous centers occur at 5- to 10-km intervals along this slow-spreading ridge. Basaltic magma intrudes the sediment fill of the axial valley, creating uplifted sediment hills, and, in some areas, erupts onto the sea floor. Large massive sulfide deposits occur along the margins of the uplifted sediment hills. The only active hydrothermal system is located on Central Hill where 220 deg C fluids construct anhydrite chimneys on pyrrhotite-rich massive sulfide mounds (Campbell and others, 1994). Central Hill is bounded by both ridge-parallel basement faults and a concentric set of faults that rim the top of the hill and may be associated with sill intrusion. Central Hill was one of the primary drill sites for Ocean Drilling Program (ODP) Leg 169. The sidescan sonar data (mosaics A, B, C, D) were collected aboard the National Oceanic and Atmospheric Administration (NOAA) research vessel Discoverer in the summer of 1996 with a 60-kHz system towed 100 to 200 m above the sea floor. Major faults and contacts are interpreted from the sidescan mosaics and 4.5-kHz seismic profiles collected simultaneously, as well as from previously conducted camera transects and submersible dives. The seismic profiles (lines 9, 11, 13) provide high-resolution subbottom structure and stratigraphy to a depth of about 50 m. In the sidescan images (mosaics A, B, C, D), bright areas denote high-energy returns from hard reflectors such as volcanic flows, sulfide deposits, or seafloor scarps. Dark areas denote low-energy returns and generally signify relatively undisturbed surface sediment. The grid lines mark one-minute intervals

  4. Detecting the presence-absence of bluefin tuna by automated analysis of medium-range sonars on fishing vessels

    PubMed Central

    Uranga, Jon; Arrizabalaga, Haritz; Boyra, Guillermo; Hernandez, Maria Carmen; Goñi, Nicolas; Arregui, Igor; Fernandes, Jose A.; Yurramendi, Yosu; Santiago, Josu

    2017-01-01

    This study presents a methodology for the automated analysis of commercial medium-range sonar signals for detecting presence/absence of bluefin tuna (Tunnus thynnus) in the Bay of Biscay. The approach uses image processing techniques to analyze sonar screenshots. For each sonar image we extracted measurable regions and analyzed their characteristics. Scientific data was used to classify each region into a class (“tuna” or “no-tuna”) and build a dataset to train and evaluate classification models by using supervised learning. The methodology performed well when validated with commercial sonar screenshots, and has the potential to automatically analyze high volumes of data at a low cost. This represents a first milestone towards the development of acoustic, fishery-independent indices of abundance for bluefin tuna in the Bay of Biscay. Future research lines and additional alternatives to inform stock assessments are also discussed. PMID:28152032

  5. Detecting the presence-absence of bluefin tuna by automated analysis of medium-range sonars on fishing vessels.

    PubMed

    Uranga, Jon; Arrizabalaga, Haritz; Boyra, Guillermo; Hernandez, Maria Carmen; Goñi, Nicolas; Arregui, Igor; Fernandes, Jose A; Yurramendi, Yosu; Santiago, Josu

    2017-01-01

    This study presents a methodology for the automated analysis of commercial medium-range sonar signals for detecting presence/absence of bluefin tuna (Tunnus thynnus) in the Bay of Biscay. The approach uses image processing techniques to analyze sonar screenshots. For each sonar image we extracted measurable regions and analyzed their characteristics. Scientific data was used to classify each region into a class ("tuna" or "no-tuna") and build a dataset to train and evaluate classification models by using supervised learning. The methodology performed well when validated with commercial sonar screenshots, and has the potential to automatically analyze high volumes of data at a low cost. This represents a first milestone towards the development of acoustic, fishery-independent indices of abundance for bluefin tuna in the Bay of Biscay. Future research lines and additional alternatives to inform stock assessments are also discussed.

  6. Exploration and discovery in Yellowstone Lake: Results from high-resolution sonar imaging, seismic reflection profiling, and submersible studies

    USGS Publications Warehouse

    Morgan, L.A.; Shanks, Wayne C.; Lovalvo, D.A.; Johnson, S.Y.; Stephenson, W.J.; Pierce, K.L.; Harlan, S.S.; Finn, C.A.; Lee, G.; Webring, M.; Schulze, B.; Duhn, J.; Sweeney, R.; Balistrieri, L.

    2003-01-01

    Discoveries from multi-beam sonar mapping and seismic reflection surveys of the northern, central, and West Thumb basins of Yellowstone Lake provide new insight into the extent of post-collapse volcanism and active hydrothermal processes occurring in a large lake environment above a large magma chamber. Yellowstone Lake has an irregular bottom covered with dozens of features directly related to hydrothermal, tectonic, volcanic, and sedimentary processes. Detailed bathymetric, seismic reflection, and magnetic evidence reveals that rhyolitic lava flows underlie much of Yellowstone Lake and exert fundamental control on lake bathymetry and localization of hydrothermal activity. Many previously unknown features have been identified and include over 250 hydrothermal vents, several very large (>500 m diameter) hydrothermal explosion craters, many small hydrothermal vent craters (???1-200 m diameter), domed lacustrine sediments related to hydrothermal activity, elongate fissures cutting post-glacial sediments, siliceous hydrothermal spire structures, sublacustrine landslide deposits, submerged former shorelines, and a recently active graben. Sampling and observations with a submersible remotely operated vehicle confirm and extend our understanding of the identified features. Faults, fissures, hydrothermally inflated domal structures, hydrothermal explosion craters, and sublacustrine landslides constitute potentially significant geologic hazards. Toxic elements derived from hydrothermal processes also may significantly affect the Yellowstone ecosystem. Published by Elsevier Science B.V.

  7. Exploration and discovery in Yellowstone Lake: results from high-resolution sonar imaging, seismic reflection profiling, and submersible studies

    NASA Astrophysics Data System (ADS)

    Morgan, L. A.; Shanks, W. C.; Lovalvo, D. A.; Johnson, S. Y.; Stephenson, W. J.; Pierce, K. L.; Harlan, S. S.; Finn, C. A.; Lee, G.; Webring, M.; Schulze, B.; Dühn, J.; Sweeney, R.; Balistrieri, L.

    2003-04-01

    'No portion of the American continent is perhaps so rich in wonders as the Yellow Stone' (F.V. Hayden, September 2, 1874) Discoveries from multi-beam sonar mapping and seismic reflection surveys of the northern, central, and West Thumb basins of Yellowstone Lake provide new insight into the extent of post-collapse volcanism and active hydrothermal processes occurring in a large lake environment above a large magma chamber. Yellowstone Lake has an irregular bottom covered with dozens of features directly related to hydrothermal, tectonic, volcanic, and sedimentary processes. Detailed bathymetric, seismic reflection, and magnetic evidence reveals that rhyolitic lava flows underlie much of Yellowstone Lake and exert fundamental control on lake bathymetry and localization of hydrothermal activity. Many previously unknown features have been identified and include over 250 hydrothermal vents, several very large (>500 m diameter) hydrothermal explosion craters, many small hydrothermal vent craters (˜1-200 m diameter), domed lacustrine sediments related to hydrothermal activity, elongate fissures cutting post-glacial sediments, siliceous hydrothermal spire structures, sublacustrine landslide deposits, submerged former shorelines, and a recently active graben. Sampling and observations with a submersible remotely operated vehicle confirm and extend our understanding of the identified features. Faults, fissures, hydrothermally inflated domal structures, hydrothermal explosion craters, and sublacustrine landslides constitute potentially significant geologic hazards. Toxic elements derived from hydrothermal processes also may significantly affect the Yellowstone ecosystem.

  8. Possible manifestations of underwater mud volcanoes based on results of sonar investigations in region of Taman Peninsula

    NASA Astrophysics Data System (ADS)

    Kaevitser, V. I.; Rimskii-Korsakov, N. A.; Smolyaninov, I. V.; Razmanov, V. M.; Krivtsov, A. P.

    2016-09-01

    This paper presents the results of three-dimensional acoustic seabed mapping in the region of the Taman Peninsula in the Black Sea using an interferometric side-scan sonar and an acoustic profiler. Mapping has revealed underwater objects identified as manifestations of underwater mud volcanism. Detailed analysis of sonar images of the relief and seabed profiles in the region of the objects has confirmed the original hypothesis.

  9. Assessment of bubble-borne methane emissions in the East Siberian Arctic Shelf via interpretation of sonar data

    NASA Astrophysics Data System (ADS)

    Chernykh, D.; Leifer, I.; Shakhova, N. E.; Semiletov, I. P.

    2014-12-01

    Arctic warming is proposed to increase methane emissions from submerged permafrost driving a positive feedback. Where emissions are from shallow seas, bubbles transport much of the methane directly, while frequent Arctic storms sparge much of the remaining dissolved methane before microbes can oxidize it. Complexity arises where emissions are small bubbles or from deeper water due to dissolution below the storm-mixed layer. Given that these emissions span a wide geographic area, a promising remote sensing technology that has been used to map and estimate emissions; however, significant uncertainties exist in sonar data interpretation due to a range of parameters affecting sonar return including bubble size distribution and spatial distribution, vertical velocity, and temperature all of which are closely inter-related in a complex and at best poorly understood manner, and change as the bubble plume rises. This process was illustrated in a series of in situ calibration experiments in the East Siberian Arctic Sea (ESAS) where controlled air bubble plumes were created and observed with sonar to quantify the relationship between sonar return and bubble plume flux for a first calibration of in situ sonar bubble plume observations in the ESAS. Results highlight the importance of bubble plume dynamics to sonar return and the absence of a simple relationship between sonar return and bubble flux. Instead sonar return related to height above seabed, even accounting for dissolution and changing hydrostatic pressure, confirming earlier laboratory studies for a deeper water column. Calibrations then were applied to field data of an area of ESAS natural seepage.

  10. Effect of level, duration, and inter-pulse interval of 1-2 kHz sonar signal exposures on harbor porpoise hearing.

    PubMed

    Kastelein, Ronald A; Hoek, Lean; Gransier, Robin; Rambags, Martijn; Claeys, Naomi

    2014-07-01

    Safety criteria for underwater low-frequency active sonar sounds produced during naval exercises are needed to protect harbor porpoise hearing. As a first step toward defining criteria, a porpoise was exposed to sequences consisting of series of 1-s, 1-2 kHz sonar down-sweeps without harmonics (as fatiguing noise) at various combinations of average received sound pressure levels (SPLs; 144-179 dB re 1 μPa), exposure durations (1.9-240 min), and duty cycles (5%-100%). Hearing thresholds were determined for a narrow-band frequency-swept sine wave centered at 1.5 kHz before exposure to the fatiguing noise, and at 1-4, 4-8, 8-12, 48, 96, 144, and 1400 min after exposure, to quantify temporary threshold shifts (TTSs) and recovery of hearing. Results show that the inter-pulse interval of the fatiguing noise is an important parameter in determining the magnitude of noise-induced TTS. For the reported range of exposure combinations (duration and SPL), the energy of the exposure (i.e., cumulative sound exposure level; SELcum) can be used to predict the induced TTS, if the inter-pulse interval is known. Exposures with equal SELcum but with different inter-pulse intervals do not result in the same induced TTS.

  11. Optimized passive sonar placement to allow improved interdiction

    NASA Astrophysics Data System (ADS)

    Johnson, Bruce A.; Matthews, Cameron

    2016-05-01

    footprint. The resulting coverage optimizes the likelihood of encounter given an arbitrary sensor profile and threat from a free field statistical model approach. The free field statistical model is particularly applicable to worst case scenario modeling in open ocean operational profiles where targets to do not follow a particular pattern in any of the modeled dimensions. We present an algorithmic testbed which shows how to achieve approximately optimal solutions to the AGP for a network of underwater sensor nodes with or without effector systems for engagement while operating under changing environmental circumstances. The means by which we accomplish this goal are three-fold: 1) Develop a 3D model for the sonar signal propagating through the underwater environment 2) Add rigorous physics-based modeling of environmental events which can affect sensor information acquisition 3) Provide innovative solutions to the AGP which account for the environmental circumstances affecting sensor performance.

  12. Biomarkers to Assess Possible Biological Effects on Reproductive Potential, Immune Function, and Energetic Fitness of Bottlenose Dolphins Exposed to Sounds Consistent with Naval Sonars

    DTIC Science & Technology

    2012-09-30

    Reproductive Potential, Immune Function, and Energetic Fitness of Bottlenose Dolphins Exposed to Sounds Consistent with Naval Sonars Dana L. Wetzel...biomarkers to examine whether significant sublethal responses to sonar-type sounds occur in bottlenose dolphins exposed to such sounds. The...investigate samples collected from trained dolphins before exposure to simulated mid-frequency sonar signals, immediately after exposure, and one week post

  13. Digital mapping of side-scan sonar data with the Woods Hole Image Processing System software

    USGS Publications Warehouse

    Paskevich, Valerie F.

    1992-01-01

    Since 1985, the Branch of Atlantic Marine Geology has been involved in collecting, processing and digitally mosaicking high and low resolution sidescan sonar data. In the past, processing and digital mosaicking has been accomplished with a dedicated, shore-based computer system. Recent development of a UNIX-based image-processing software system includes a series of task specific programs for pre-processing sidescan sonar data. To extend the capabilities of the UNIX-based programs, development of digital mapping techniques have been developed. This report describes the initial development of an automated digital mapping procedure. Included is a description of the programs and steps required to complete the digital mosaicking on a UNIXbased computer system, and a comparison of techniques that the user may wish to select.

  14. Assessing the Effectiveness of Ramp-Up During Sonar Operations Using Exposure Models.

    PubMed

    von Benda-Beckmann, Alexander M; Wensveen, Paul J; Kvadsheim, Petter H; Lam, Frans-Peter A; Miller, Patrick J O; Tyack, Peter L; Ainslie, Michael A

    2016-01-01

    Ramp-up procedures are used to mitigate the impact of sound on marine mammals. Sound exposure models combined with observations of marine mammals responding to sound can be used to assess the effectiveness of ramp-up procedures. We found that ramp-up procedures before full-level sonar operations can reduce the risk of hearing threshold shifts with marine mammals, but their effectiveness depends strongly on the responsiveness of the animals. In this paper, we investigated the effect of sonar parameters (source level, pulse-repetition time, ship speed) on sound exposure by using a simple analytical model and highlight the mechanisms that limit the effectiveness of ramp-up procedures.

  15. Model-based adaptive 3D sonar reconstruction in reverberating environments.

    PubMed

    Saucan, Augustin-Alexandru; Sintes, Christophe; Chonavel, Thierry; Caillec, Jean-Marc Le

    2015-10-01

    In this paper, we propose a novel model-based approach for 3D underwater scene reconstruction, i.e., bathymetry, for side scan sonar arrays in complex and highly reverberating environments like shallow water areas. The presence of multipath echoes and volume reverberation generates false depth estimates. To improve the resulting bathymetry, this paper proposes and develops an adaptive filter, based on several original geometrical models. This multimodel approach makes it possible to track and separate the direction of arrival trajectories of multiple echoes impinging the array. Echo tracking is perceived as a model-based processing stage, incorporating prior information on the temporal evolution of echoes in order to reject cluttered observations generated by interfering echoes. The results of the proposed filter on simulated and real sonar data showcase the clutter-free and regularized bathymetric reconstruction. Model validation is carried out with goodness of fit tests, and demonstrates the importance of model-based processing for bathymetry reconstruction.

  16. Machine Learning Approaches to Classification of Seafloor Features from High Resolution Sonar Data

    NASA Astrophysics Data System (ADS)

    Smith, D. G.; Ed, L.; Sofge, D.; Elmore, P. A.; Petry, F.

    2014-12-01

    Navigation charts provide topographic maps of the seafloor created from swaths of sonar data. Converting sonar data to a topographic map is a manual, labor-intensive process that can be greatly assisted by contextual information obtained from automated classification of geomorphological structures. Finding structures such as seamounts can be challenging, as there are no established rules that can be used for decision-making. Often times, it is a determination that is made by human expertise. A variety of feature metrics may be useful for this task and we use a large number of metrics relevant to the task of finding seamounts. We demonstrate this ability in locating seamounts by two related machine learning techniques. As well as achieving good accuracy in classification, the human-understandable set of metrics that are most important for the results are discussed.

  17. Evaluation of the Performance of the Distributed Phased-MIMO Sonar

    PubMed Central

    Pan, Xiang; Jiang, Jingning; Wang, Nan

    2017-01-01

    A broadband signal model is proposed for a distributed multiple-input multiple-output (MIMO) sonar system consisting of two transmitters and a receiving linear array. Transmitters are widely separated to illuminate the different aspects of an extended target of interest. The beamforming technique is utilized at the reception ends for enhancement of weak target echoes. A MIMO detector is designed with the estimated target position parameters within the general likelihood rate test (GLRT) framework. For the high signal-to-noise ratio case, the detection performance of the MIMO system is better than that of the phased-array system in the numerical simulations and the tank experiments. The robustness of the distributed phased-MIMO sonar system is further demonstrated in localization of a target in at-lake experiments. PMID:28085071

  18. Sidescan-sonar surveys of critical habitats in Long Island Sound, Connecticut

    USGS Publications Warehouse

    Poppe, L.J.; Lewis, R.S.; Zajac, Roman; Twichell, D.C.; Knebel, H. J.

    1995-01-01

    The Long Island Sound estuary is located in the most densely populated region of the U.S.. Due to the enormous surrounding population, large inputs of anthropogenic wastes and toxic chemicals, benthic habitats were degraded. To address this environmental problem, sidescan-sonar mosaics are being developed within specific areas of critical concern. Detailed bathymetric and high-resolution seismic-reflection data assist in interpretations of relief, to relate bottom features to the underlying stratigraphy, and to estimate thicknesses of surficial sediments. To date, several continuous-coverage sidescan-sonar surveys have been completed. These surveys show that the sedimentary environments and benthic habitats in Long Island Sound vary spatially over short distances.

  19. Texture-based discrimination of man-made and natural objects in sidescan sonar imagery

    NASA Astrophysics Data System (ADS)

    Kessel, Ronald T.

    2003-08-01

    High-resolution sidescan sonars are often used in underwater warfare for large-area surveys of the seafloor in the search for sea mines. Much effort has gone toward the automatic detection of sea mines. In its more advanced forms, such auto-detection entails pattern recognition: the automatic assignment of class labels (target/non-target) to signatures according to their distinctive features. This paper demonstrates a texture-based feature for automatically discriminating between man-made and natural objects. Real sonar data is used, and the demonstration includes performance estimates in the form of the receiver-operator characteristic (ROC) curves necessary (though often omitted) for evaluating detectors for operational use. The merits of redefining the allowable automatic responses-from the classes of mine targets ultimately sought, to the class of man-made objects more generally-are reviewed from both the pattern-recognition and operational perspectives.

  20. Evaluation of the Performance of the Distributed Phased-MIMO Sonar.

    PubMed

    Pan, Xiang; Jiang, Jingning; Wang, Nan

    2017-01-11

    A broadband signal model is proposed for a distributed multiple-input multiple-output (MIMO) sonar system consisting of two transmitters and a receiving linear array. Transmitters are widely separated to illuminate the different aspects of an extended target of interest. The beamforming technique is utilized at the reception ends for enhancement of weak target echoes. A MIMO detector is designed with the estimated target position parameters within the general likelihood rate test (GLRT) framework. For the high signal-to-noise ratio case, the detection performance of the MIMO system is better than that of the phased-array system in the numerical simulations and the tank experiments. The robustness of the distributed phased-MIMO sonar system is further demonstrated in localization of a target in at-lake experiments.

  1. Real-Time Bathymetry and Backscatter Mosaic Software for Towed and Shipboard Mapping Sonars

    NASA Astrophysics Data System (ADS)

    Davis, R. B.; Appelgate, T. B.; Johnson, P. D.

    2006-12-01

    The Hawaii Mapping Research Group (HMRG) of the University of Hawaii has developed a bathymetry and backscatter mosaic software package that is suitable for use either in real-time survey operations or non-real- time processing applications. The system was originally developed for use with HMRG's own towed sonar systems but is also compatible with shipboard multibeam systems. It has been operational on R/V Kilo Moana under the supervision of the University's Ocean Technology Group marine science technicians for well over a year in support of that vessel's Kongsberg/Simrad EM120 and EM1002 multibeams. The software grids and renders incoming data in geo-referenced chart-like displays. Data are typically processed in three operator-selectable resolutions limited only by the processing and storage capabilities of the Linux- or Unix-based host computer system. A master navigation chart shows survey tracklines and swath coverage -- from this chart the user can simultaneously open multiple mosaic views into the underlying bathymetry and backscatter datasets with independent resolutions and display properties (e.g., contour color key and interval for bathymetry, grayscale mapping for backscatter, region of interest, etc.) All displays are optimized for quick pan and zoom operations and include on-screen interface control features which permit numerous display parameters to be rapidly changed. All mosaic views, as well as the master navigation display, can be updated in real-time as new data are supplied by the mapping instrument and can also display a background reference dataset for comparison with incoming instrument data. The software also includes survey-planning features which permit new survey waypoints to be generated interactively with reference to incoming and/or historical background data. Aboard R/V Kilo Moana a pair of dual-monitor computer systems, one for the EM120 and one for the EM1002, are available for the processing and display of incoming data from

  2. Side Scan Sonar Target Detection in the Presence of Bottom Backscatter

    DTIC Science & Technology

    1983-09-01

    manifested in the form of depth contours depicted throughout the ra;ion. Whether this task is performed by hand or by machine , it inevitably remains...capability. An important contribution has been digital processing with memory for data storage which allows post- proccessing playback of tape...environmental conditions, The sonar equation is a tool to aid in that prediction. By substituting into the equation the spocific operating variables of the

  3. Discrete-Mode Source Development and Testing for New Seismo-Acoustic Sonar

    DTIC Science & Technology

    1998-03-01

    the English scientist, Lord Rayleigh (J.W. Strutt ) [Ref. 6] demonstrated theoretically that there exist waves that can propagate over the planar...and T.G. Muir, Aug. 1994. 6. Rayleigh , Lord (J.W. Strutt ), "On Waves Propagated along the Plane Surface of an Elastic Solid," Proceedings London...13. ABSTRACT (maximum 200 words) A seismo-acoustic sonar concept that uses guided interface waves ( Rayleigh or Schölte) is being developed to

  4. Signal-to-symbol transformation: a summary of HASP/SIAP case study (sonar data)

    SciTech Connect

    Penny Nii, H.

    1983-01-01

    In the past fifteen years, ai scientists have built several signal interpretation, or understanding, programs. HASP/SIAP is one such program which tries to interest the meaning of sonar data in a particular context. An attempt is made to present a methodology for understanding signal data and to show that the traditional signal processing is but one part of the interpretation task. HASP/SIAP is also an expert system. 12 references.

  5. 3S2 - Behavioral Response Studies of Cetaceans to Naval Sonar Signals in Norwegian Waters

    DTIC Science & Technology

    2012-09-30

    behavioural response thresholds during experimental exposures, and to compare these to responses to no-sonar controls and playback of killer whale ...research effort (see related programs) with killer , sperm, and long-finned pilot whales provides a dataset that enables comparative analysis of...successful collection of additional playback of killer whale sounds to long- finned pilot whales and sperm whales in the 2010 baseline cruise under this

  6. 3S2 - Behavioral Response Studies of Cetaceans to Navy Sonar Signals in Norwegian Waters

    DTIC Science & Technology

    2012-09-30

    behavioral response thresholds during experimental exposures, and to compare these to responses to no-sonar controls and playback of killer whale ...research effort (see related programs) with killer , sperm, and long-finned pilot whales provides a dataset that enables comparative analysis of behavioral...experiments of killer whale sounds to long-finned pilot whales and sperm whales in the 2010 baseline cruise under this award, the behavioral responses of

  7. 3S2: Behavioral Response Studies of Cetaceans to Navy Sonar Signals in Norwegian Waters

    DTIC Science & Technology

    2013-09-30

    experiments, and to compare these to responses to no-sonar controls and playback of killer whale sounds; 2.) Conduct a directed study on the...experiments follow the same protocol of escalating the level received by the whale subject in order to identify response thresholds. Playback of killer ...focused upon conducting playback experiments of mammal-eating killer whale sounds to long-finned pilot whales with additional control stumuli also

  8. Investigation of measureable parameters that correlate with automatic target recognition performance in synthetic aperture sonar

    NASA Astrophysics Data System (ADS)

    Gazagnaire, Julia; Cobb, J. T.; Isaacs, Jason

    2015-05-01

    There is a desire in the Mine Counter Measure community to develop a systematic method to predict and/or estimate the performance of Automatic Target Recognition (ATR) algorithms that are detecting and classifying mine-like objects within sonar data. Ideally, parameters exist that can be measured directly from the sonar data that correlate with ATR performance. In this effort, two metrics were analyzed for their predictive potential using high frequency synthetic aperture sonar (SAS) images. The first parameter is a measure of contrast. It is essentially the variance in pixel intensity over a fixed partition of relatively small size. An analysis was performed to determine the optimum block size for this contrast calculation. These blocks were then overlapped in the horizontal and vertical direction over the entire image. The second parameter is the one-dimensional K-shape parameter. The K-distribution is commonly used to describe sonar backscatter return from range cells that contain a finite number of scatterers. An Ada-Boosted Decision Tree classifier was used to calculate the probability of classification (Pc) and false alarm rate (FAR) for several types of targets in SAS images from three different data sets. ROC curves as a function of the measured parameters were generated and the correlation between the measured parameters in the vicinity of each of the contacts and the ATR performance was investigated. The contrast and K-shape parameters were considered separately. Additionally, the contrast and K-shape parameter were associated with background texture types using previously labeled high frequency SAS images.

  9. Monitoring Beaked Whale Responses to Sonar Tests at the Atlantic Undersea Test and Evaluation Center (AUTEC)

    DTIC Science & Technology

    2011-11-01

    whales, Cuvier’s beaked whale, Blainville’s beaked whale, sperm whale, pilot whale, melon -headed whale, photo-identification, sonar exposure. 16...sperm whales (Physeter macrocephalus), pilot whales (Globicephala macrorhynchus) and melon -headed whales (Peponocephala electra), and will increase...172 9.3 Sperm whale 9 109 2 Melon -headed whale 40 22 0 Pygmy sperm whale 2 1 0 06-May-11 125 11.1 Sperm whale 9 430 5 Melon -headed whale 25 47 0

  10. Sidescan-sonar data collected during May 1978 from the southern New England continental shelf

    USGS Publications Warehouse

    McClennen, Charles E.

    1981-01-01

    Sidescan-sonar data were collected aboard R/V WESTWARD (Cruise W-39-4) during May 1978 by the U.S. Geological Survey using an Ocean Research Equipment System. Navigation in the study area was by Loran C. The 368 kilometers of survey were conducted in Block Island Sound, in Rhode Island Sound, and over the mid-Continental Shelf south of Block Island and Martha's Vineyard (Fig. 1).

  11. Target Motion Effects on Passive Sonar: An Appraisal of Basic Factors.

    DTIC Science & Technology

    1986-12-01

    observation times for constant speed and heading conditions. j Keywords - DETECTION FREQUENCY DOMAIN- MONTECARLO TECHNIQUE PASSIVE SONAR’ PROBABILITY DENSITY...TIME, 14 B - MONTECARLO TECHNIQUE, 31 ii SACLANTCEN SM-192 1. Introduction The normal passive detection system involves, in general , the assumption...calculated with the method described in Sect. A.2 of Appendix A and the results are shown in Figs. 8 and 9. Results obtained using a Montecarlo

  12. Processing, mosaicking and management of the Monterey Bay digital sidescan-sonar images

    USGS Publications Warehouse

    Chavez, P.S.; Isbrecht, J.; Galanis, P.; Gabel, G.L.; Sides, S.C.; Soltesz, D.L.; Ross, S.L.; Velasco, M.G.

    2002-01-01

    Sidescan-sonar imaging systems with digital capabilities have now been available for approximately 20 years. In this paper we present several of the various digital image processing techniques developed by the U.S. Geological Survey (USGS) and used to apply intensity/radiometric and geometric corrections, as well as enhance and digitally mosaic, sidescan-sonar images of the Monterey Bay region. New software run by a WWW server was designed and implemented to allow very large image data sets, such as the digital mosaic, to be easily viewed interactively, including the ability to roam throughout the digital mosaic at the web site in either compressed or full 1-m resolution. The processing is separated into the two different stages: preprocessing and information extraction. In the preprocessing stage, sensor-specific algorithms are applied to correct for both geometric and intensity/radiometric distortions introduced by the sensor. This is followed by digital mosaicking of the track-line strips into quadrangle format which can be used as input to either visual or digital image analysis and interpretation. An automatic seam removal procedure was used in combination with an interactive digital feathering/stenciling procedure to help minimize tone or seam matching problems between image strips from adjacent track-lines. The sidescan-sonar image processing package is part of the USGS Mini Image Processing System (MIPS) and has been designed to process data collected by any 'generic' digital sidescan-sonar imaging system. The USGS MIPS software, developed over the last 20 years as a public domain package, is available on the WWW at: http://terraweb.wr.usgs.gov/trs/software.html.

  13. A Kernel Machine Framework for Feature Optimization in Multi-frequency Sonar Imagery

    DTIC Science & Technology

    2006-09-01

    best performance with the fewest number of basis Table III OBJECT MEASUREMENTS USED TO CONSTRUCT FEATURES Textural Measurements GLCM Contrast...each object in each image, 17 measurements are made and used to construct the features . Of these 17 measurements, 5 are textural based and are...A Kernel Machine Framework for Feature Optimization in Multi-frequency Sonar Imagery J.R. Stack and R. Arrieta Naval Surface Warfare Center

  14. Evaluation and Application of GRP Composite Fasteners for Sonar Dome Components

    DTIC Science & Technology

    1999-10-01

    the USA were contacted in order to obtain information on commercially available composite fasteners (see Koko et al. 1998). Information was obtained...Santa Anna, California, (1996). Koko , T.S., Connor, M.J. and Corbett, C.V. (1997). "Development of a Composite Fairing Band Assembly for A...Stainless Steel Sonar Dome". Proceedings ofiCCM-11, Gold Coast Australia, pp. I-426 - I-435. Koko , T.S. (1998). "Development of Prototype Composite

  15. Tempo and mode of antibat ultrasound production and sonar jamming in the diverse hawkmoth radiation.

    PubMed

    Kawahara, Akito Y; Barber, Jesse R

    2015-05-19

    The bat-moth arms race has existed for over 60 million y, with moths evolving ultrasonically sensitive ears and ultrasound-producing organs to combat bat predation. The evolution of these defenses has never been thoroughly examined because of limitations in simultaneously conducting behavioral and phylogenetic analyses across an entire group. Hawkmoths include >1,500 species worldwide, some of which produce ultrasound using genital stridulatory structures. However, the function and evolution of this behavior remain largely unknown. We built a comprehensive behavioral dataset of hawkmoth hearing and ultrasonic reply to sonar attack using high-throughput field assays. Nearly half of the species tested (57 of 124 species) produced ultrasound to tactile stimulation or playback of bat echolocation attack. To test the function of ultrasound, we pitted big brown bats (Eptesicus fuscus) against hawkmoths over multiple nights and show that hawkmoths jam bat sonar. Ultrasound production was immediately and consistently effective at thwarting attack and bats regularly performed catching behavior without capturing moths. We also constructed a fossil-calibrated, multigene phylogeny to study the evolutionary history and divergence times of these antibat strategies across the entire family. We show that ultrasound production arose in multiple groups, starting in the late Oligocene (∼ 26 Ma) after the emergence of insectivorous bats. Sonar jamming and bat-detecting ears arose twice, independently, in the Miocene (18-14 Ma) either from earless hawkmoths that produced ultrasound in response to physical contact only, or from species that did not respond to touch or bat echolocation attack.

  16. Recommendations for the use of ultrasound in rheumatoid arthritis: literature review and SONAR score experience.

    PubMed

    Zufferey, Pascal; Tamborrini, Giorgio; Gabay, Cem; Krebs, Andreas; Kyburz, Diego; Michel, Beat; Moser, Urs; Villiger, Peter M; So, Alexander; Ziswiler, Hans Rudolf

    2013-12-20

    Ultrasound (US) has become a useful tool in the detection of early disease, differential diagnosis, guidance of treatment decisions and treatment monitoring of rheumatoid arthritis (RA). In 2008, the Swiss Sonography in Arthritis and Rheumatism (SONAR) group was established to promote the use of US in inflammatory arthritis in clinical practice. A scoring system was developed and taught to a large number of Swiss rheumatologists who already contributed to the Swiss Clinical Quality Management (SCQM) database, a national patient register. This paper intends to give a Swiss consensus about best clinical practice recommendations for the use of US in RA on the basis of the current literature knowledge and experience with the Swiss SONAR score. Literature research was performed to collect data on current evidence. The results were discussed among specialists of the Swiss university centres and private practice, following a structured procedure. Musculoskelatal US was found to be very helpful in establishing the diagnosis and monitoring the evolution of RA, and to be a reliable tool if used by experienced examiners. It influences treatment decisions such as continuing, intensifying or stepping down therapy. The definite modalities of integrating US into the diagnosis and monitoring of RA treatments will be defined within a few years. There are, however, strong arguments to use US findings as of today in daily clinical care. Some practical recommendations about the use of US in RA, focusing on the diagnosis and the use of the SONAR score, are proposed.

  17. PMHT Approach for Multi-Target Multi-Sensor Sonar Tracking in Clutter.

    PubMed

    Li, Xiaohua; Li, Yaan; Yu, Jing; Chen, Xiao; Dai, Miao

    2015-11-06

    Multi-sensor sonar tracking has many advantages, such as the potential to reduce the overall measurement uncertainty and the possibility to hide the receiver. However, the use of multi-target multi-sensor sonar tracking is challenging because of the complexity of the underwater environment, especially the low target detection probability and extremely large number of false alarms caused by reverberation. In this work, to solve the problem of multi-target multi-sensor sonar tracking in the presence of clutter, a novel probabilistic multi-hypothesis tracker (PMHT) approach based on the extended Kalman filter (EKF) and unscented Kalman filter (UKF) is proposed. The PMHT can efficiently handle the unknown measurements-to-targets and measurements-to-transmitters data association ambiguity. The EKF and UKF are used to deal with the high degree of nonlinearity in the measurement model. The simulation results show that the proposed algorithm can improve the target tracking performance in a cluttered environment greatly, and its computational load is low.

  18. Real-time synthetic aperture sonar imaging using a parallel architecture.

    PubMed

    Riyait, V S; Lawlor, M A; Adams, A E; Hinton, O; Sharif, B

    1995-01-01

    This paper describes a parallel architecture that has been developed to perform real-time synthetic aperture sonar imaging as part of the Acoustical Imaging Development (ACID) project. The project has successfully developed a synthetic aperture sonar system for producing high resolution images of the sea floor and that has been tested during a series of sea trials in May 1993 off the south coast of France. This paper describes the synthetic aperture processing system developed by the University of Newcastle upon Tyne and its use of transputer modules and associated devices in order to obtain real-time imaging performance, the software structure of the processing system and the load balancing techniques that have been developed in order to provide efficient processing. The use of a parallel distributed architecture has also allowed a processing system that can readily be extended to deliver greater computational power in the future. Images produced by the synthetic aperture processor from data collected from around the Toulon coastal region are presented. These images highlight the improvement in azimuth resolution that can be obtained from synthetic aperture processing over conventional sidescan sonars.

  19. Survey of dual frequency identification sonar (DIDSON) applications in fisheries assessment and behavioral studies

    NASA Astrophysics Data System (ADS)

    Belcher, Edward O.

    2005-04-01

    The Dual Frequency Identification Sonar (DIDSON) is a forward-looking sonar that operates in shallow riverine environments with rocky, uneven substrates and near concrete structures such as dams. This allows a number of fisheries applications in environments previously too hostile for reliable sonar operation. Currently 35 DIDSONs have been obtained by 16 groups to accomplish a variety of fish assessment and behavioral studies. This paper surveys the work of these groups and highlights novel assessments allowed by this new acoustic tool. The groups include Alaska Department of Fish and Game, U.S. Fish and Wildlife Service, NOAA, USGS, Bureau of Reclamation, California Department of Water Resources, Pacific Northwest National Laboratories, Nez Perce Tribal Fisheries, Puyallup Tribal Fisheries, Department of Fisheries and Oceans Canada, and Fisheries Engineering Japan. Assessments include: (1) Counting fish migrating up rivers of various sizes, bottom substrates, turbidity, and velocity; (2) Analysis of fish behavior at (A) prototype fish protection devices on dams, (B) irrigation intakes along muddy rivers, (C) intakes of trawl nets; and (3) Detection and measurement of redds in alluvial riverbeds. [Work for the survey supported by Sound Metrics Corp.

  20. Target re-acquisition using acoustic features with an autonomous underwater vehicle-borne sonar

    NASA Astrophysics Data System (ADS)

    Edwards, Joseph; Schmidt, Henrik

    2003-10-01

    Concurrent mapping and localization (CML) is a technique for unsupervised feature-based mapping of unknown environments, and is an essential tool for autonomous robots. For land robots, CML can be applied using video, laser, or acoustic sensors, while for autonomous underwater vehicles (AUVs) the only effective transducer in most situations is sonar. In the Generic Oceanographic Array Technology Sonar (GOATS) experiment series, CML was effectively demonstrated using a single AUV. A further hurdle in the full implementation of AUV minehunting is to re-acquire and identify targets of interest. Target re-acquisition allows other vehicles to be called into a target location to further investigate with adaptive sonar geometries or alternative sensor suites designed for classification. In this work, the features in the CML-generated map are extended from only spatial coordinates to include acoustic features such as spectral response. It is demonstrated that the inclusion of acoustic features aids in the global positioning within the map, although the fine positioning is still accomplished through standard CML. In addition, areas that are sparsely populated with targets, e.g., a sandy coastline, are shown to be more readily navigable using acoustic features.

  1. Detecting submerged objects: the application of side scan sonar to forensic contexts.

    PubMed

    Schultz, John J; Healy, Carrie A; Parker, Kenneth; Lowers, Bim

    2013-09-10

    Forensic personnel must deal with numerous challenges when searching for submerged objects. While traditional water search methods have generally involved using dive teams, remotely operated vehicles (ROVs), and water scent dogs for cases involving submerged objects and bodies, law enforcement is increasingly integrating multiple methods that include geophysical technologies. There are numerous advantages for integrating geophysical technologies, such as side scan sonar and ground penetrating radar (GPR), with more traditional search methods. Overall, these methods decrease the time involved searching, in addition to increasing area searched. However, as with other search methods, there are advantages and disadvantages when using each method. For example, in instances with excessive aquatic vegetation or irregular bottom terrain, it may not be possible to discern a submersed body with side scan sonar. As a result, forensic personnel will have the highest rate of success during searches for submerged objects when integrating multiple search methods, including deploying multiple geophysical technologies. The goal of this paper is to discuss the methodology of various search methods that are employed for submerged objects and how these various methods can be integrated as part of a comprehensive protocol for water searches depending upon the type of underwater terrain. In addition, two successful case studies involving the search and recovery of a submerged human body using side scan sonar are presented to illustrate the successful application of integrating a geophysical technology with divers when searching for a submerged object.

  2. Multibeam sonar (DIDSON) assessment of American shad (Alosa sapidissima) approaching a hydroelectric dam

    USGS Publications Warehouse

    Grote, Ann B.; Bailey, Michael M.; Zydlewski, Joseph; Hightower, Joseph E.

    2014-01-01

    We investigated the fish community approaching the Veazie Dam on the Penobscot River, Maine, prior to implementation of a major dam removal and river restoration project. Multibeam sonar (dual-frequency identification sonar, DIDSON) surveys were conducted continuously at the fishway entrance from May to July in 2011. A 5% subsample of DIDSON data contained 43 793 fish targets, the majority of which were of Excellent (15.7%) or Good (73.01%) observation quality. Excellent quality DIDSON targets (n = 6876) were apportioned by species using a Bayesian mixture model based on four known fork length distributions (river herring (alewife,Alosa psuedoharengus, and blueback herring, Alosa aestivalis), American shad, Alosa sapidissima) and two size classes (one sea-winter and multi-sea-winter) of Atlantic salmon (Salmo salar). 76.2% of targets were assigned to the American shad distribution; Atlantic salmon accounted for 15.64%, and river herring 8.16% of observed targets. Shad-sized (99.0%) and salmon-sized (99.3%) targets approached the fishway almost exclusively during the day, whereas river herring-sized targets were observed both during the day (51.1%) and at night (48.9%). This approach demonstrates how multibeam sonar imaging can be used to evaluate community composition and species-specific movement patterns in systems where there is little overlap in the length distributions of target species.

  3. SONAR: A High-Throughput Pipeline for Inferring Antibody Ontogenies from Longitudinal Sequencing of B Cell Transcripts.

    PubMed

    Schramm, Chaim A; Sheng, Zizhang; Zhang, Zhenhai; Mascola, John R; Kwong, Peter D; Shapiro, Lawrence

    2016-01-01

    The rapid advance of massively parallel or next-generation sequencing technologies has made possible the characterization of B cell receptor repertoires in ever greater detail, and these developments have triggered a proliferation of software tools for processing and annotating these data. Of especial interest, however, is the capability to track the development of specific antibody lineages across time, which remains beyond the scope of most current programs. We have previously reported on the use of techniques such as inter- and intradonor analysis and CDR3 tracing to identify transcripts related to an antibody of interest. Here, we present Software for the Ontogenic aNalysis of Antibody Repertoires (SONAR), capable of automating both general repertoire analysis and specialized techniques for investigating specific lineages. SONAR annotates next-generation sequencing data, identifies transcripts in a lineage of interest, and tracks lineage development across multiple time points. SONAR also generates figures, such as identity-divergence plots and longitudinal phylogenetic "birthday" trees, and provides interfaces to other programs such as DNAML and BEAST. SONAR can be downloaded as a ready-to-run Docker image or manually installed on a local machine. In the latter case, it can also be configured to take advantage of a high-performance computing cluster for the most computationally intensive steps, if available. In summary, this software provides a useful new tool for the processing of large next-generation sequencing datasets and the ontogenic analysis of neutralizing antibody lineages. SONAR can be found at https://github.com/scharch/SONAR, and the Docker image can be obtained from https://hub.docker.com/r/scharch/sonar/.

  4. SONAR: A High-Throughput Pipeline for Inferring Antibody Ontogenies from Longitudinal Sequencing of B Cell Transcripts

    PubMed Central

    Schramm, Chaim A.; Sheng, Zizhang; Zhang, Zhenhai; Mascola, John R.; Kwong, Peter D.; Shapiro, Lawrence

    2016-01-01

    The rapid advance of massively parallel or next-generation sequencing technologies has made possible the characterization of B cell receptor repertoires in ever greater detail, and these developments have triggered a proliferation of software tools for processing and annotating these data. Of especial interest, however, is the capability to track the development of specific antibody lineages across time, which remains beyond the scope of most current programs. We have previously reported on the use of techniques such as inter- and intradonor analysis and CDR3 tracing to identify transcripts related to an antibody of interest. Here, we present Software for the Ontogenic aNalysis of Antibody Repertoires (SONAR), capable of automating both general repertoire analysis and specialized techniques for investigating specific lineages. SONAR annotates next-generation sequencing data, identifies transcripts in a lineage of interest, and tracks lineage development across multiple time points. SONAR also generates figures, such as identity–divergence plots and longitudinal phylogenetic “birthday” trees, and provides interfaces to other programs such as DNAML and BEAST. SONAR can be downloaded as a ready-to-run Docker image or manually installed on a local machine. In the latter case, it can also be configured to take advantage of a high-performance computing cluster for the most computationally intensive steps, if available. In summary, this software provides a useful new tool for the processing of large next-generation sequencing datasets and the ontogenic analysis of neutralizing antibody lineages. SONAR can be found at https://github.com/scharch/SONAR, and the Docker image can be obtained from https://hub.docker.com/r/scharch/sonar/. PMID:27708645

  5. Mudflows in the Southwest Pass Region of the Mississippi River Delta: Results From Multibeam, Sidescan Sonar, and Subbottom Profiler Data

    NASA Astrophysics Data System (ADS)

    Henning, A. T.; Garcia-Garcia, A.; Orange, A.; Orange, D.

    2007-12-01

    The offshore portion of the active Mississippi delta is characterized by frequent submarine mudflows, which have caused extensive damage to offshore infrastructure in the area. The slopes in this area are very gentle (typically < 1.5°) and the mudflows are thought to be triggered by deep waves during storms. The 2005 hurricane season in particular caused unprecedented levels of damage in the Gulf of Mexico. Post-hurricane surveys carried out by the industry determined that much of the damage was caused by mudflows that originated on the upper portions of the Mississippi birdsfoot delta, just outboard of Southwest Pass. Mudflows generally consist of a source area, a chute (or gully), and a downslope depositional lobe. Large erratic blocks are characteristic of the mudflow gully floor, and recently emplaced mudflow lobes show a more irregular and blocky surface topography. Gullies often form natural levees, which can give the gully a perched topographic expression. A June 2007 survey aboard the UNOLS vessel R/V Pelican focused on the upslope portion of the mudflow area with the goal of imaging the source of the mudflows. Multibeam echosounder, sidescan sonar, and subbottom profiler data were acquired over an 8 km by 2 km grid at a 100 m line spacing in order to study the possible sources of the mudflows. Multibeam and sidescan sonar data imaged the upslope portions of eight separate mudflows, including the origin of one of the flows. The five westernmost flows originate at a known dredge dump site and appear significantly wider than the three flows to the east. The eastern flows are more clearly delineated on the seafloor data and follow more tortuous downslope paths. This suggests a possible anthropogenic component to mudflow sourcing in this area. The subbottom profiler data show large blocks of material containing intact stratigraphy located within the mudflow gullies. High dips were observed in numerous blocks in both the strike and dip directions. The base of

  6. Enhanced echolocation via robust statistics and super-resolution of sonar images

    NASA Astrophysics Data System (ADS)

    Kim, Kio

    Echolocation is a process in which an animal uses acoustic signals to exchange information with environments. In a recent study, Neretti et al. have shown that the use of robust statistics can significantly improve the resiliency of echolocation against noise and enhance its accuracy by suppressing the development of sidelobes in the processing of an echo signal. In this research, the use of robust statistics is extended to problems in underwater explorations. The dissertation consists of two parts. Part I describes how robust statistics can enhance the identification of target objects, which in this case are cylindrical containers filled with four different liquids. Particularly, this work employs a variation of an existing robust estimator called an L-estimator, which was first suggested by Koenker and Bassett. As pointed out by Au et al.; a 'highlight interval' is an important feature, and it is closely related with many other important features that are known to be crucial for dolphin echolocation. A varied L-estimator described in this text is used to enhance the detection of highlight intervals, which eventually leads to a successful classification of echo signals. Part II extends the problem into 2 dimensions. Thanks to the advances in material and computer technology, various sonar imaging modalities are available on the market. By registering acoustic images from such video sequences, one can extract more information on the region of interest. Computer vision and image processing allowed application of robust statistics to the acoustic images produced by forward looking sonar systems, such as Dual-frequency Identification Sonar and ProViewer. The first use of robust statistics for sonar image enhancement in this text is in image registration. Random Sampling Consensus (RANSAC) is widely used for image registration. The registration algorithm using RANSAC is optimized for sonar image registration, and the performance is studied. The second use of robust

  7. Mid-water Software Tools and the Application to Processing and Analysis of the Latest Generation Multibeam Sonars

    NASA Astrophysics Data System (ADS)

    Gee, L.; Doucet, M.

    2010-12-01

    The latest generation of multibeam sonars now has the ability to map the water-column, along with the seafloor. Currently, the users of these sonars have a limited view of the mid-water data in real-time, and if they do store the data, they are restricted to replaying it only, with no ability for further analysis. The water-column data has the potential to address a number of research areas including detection of small targets (wrecks, etc.) above the seabed, mapping of fish and marine mammals and a wide range of physical oceanographic processes. However, researchers have been required to develop their own in-house software tools before they can even begin their study of the water column data. This paper describes the development of more general software tools for the full processing of raw sonar data (bathymetry, backscatter and water-column) to yield output products suitable for visualization in a 4D time-synchronized environment. The huge water-column data volumes generated by the new sonars, combined with the variety of data formats from the different sonar manufacturers, provides a significant challenge in the design and development of tools that can be applied to the wide variety of applications. The development of the mid-water tools on this project addressed this problem by using a unified way of storing the water column data in a generic water column format (GWC). The sonar data are converted into the GWC by re-integrating the water column packets with time-based navigation and attitude, such that downstream in the workflow, the tools will have access to all relevant data of any particular ping. Dependent on the application and the resolution requirements, the conversion process also allows simple sub-sampling. Additionally, each file is indexed to enable fast non-linear lookup and extraction of any packet type or packet type collection in the sonar file. These tools also fully exploit multi-core and hyper-threading technologies to maximize the throughput

  8. Salmon escapement estimates into the Togiak River using sonar, Togiak National Wildlife Refuge, Alaska, 1987, 1988, and 1990

    USGS Publications Warehouse

    Irving, David B.; Finn, James E.; Larson, James P.

    1995-01-01

    We began a three year study in 1987 to test the feasibility of using sonar in the Togiak River to estimate salmon escapements. Current methods rely on periodic aerial surveys and a counting tower at river kilometer 97. Escapement estimates are not available until 10 to 14 days after the salmon enter the river. Water depth and turbidity preclude relocating the tower to the lower river and affect the reliability of aerial surveys. To determine whether an alternative method could be developed to improve the timeliness and accuracy of current escapement monitoring, Bendix sonar units were operated during 1987, 1988, and 1990. Two sonar stations were set up opposite each other at river kilometer 30 and were operated 24 hours per day, seven days per week. Catches from gill nets with 12, 14, and 20 cm stretch mesh, a beach seine, and visual observations were used to estimate species composition. Length and sex data were collected from salmon caught in the nets to assess sampling bias.In 1987, sonar was used to select optimal sites and enumerate coho salmon. In 1988 and 1990, the sites identified in 1987 were used to estimate the escapement of five salmon species. Sockeye salmon escapement was estimated at 512,581 and 589,321, chinook at 7,698 and 15,098, chum at 246,144 and 134,958, coho at 78,588 and 28,290, and pink at 96,167 and 131,484. Sonar estimates of sockeye salmon were two to three times the Alaska Department of Fish and Game's escapement estimate based on aerial surveys and tower counts. The source of error was probably a combination of over-estimating the total number of targets counted by the sonar and by incorrectly estimating species composition.Total salmon escapement estimates using sonar may be feasible but several more years of development are needed. Because of the overlapped salmon run timing, estimating species composition appears the most difficult aspect of using sonar for management. Possible improvements include using a larger beach seine or

  9. Evaluating the use of side-scan sonar for detecting freshwater mussel beds in turbid river environments

    USGS Publications Warehouse

    Powers, Jarrod; Brewer, Shannon K.; Long, James M.; Campbell, Thomas

    2015-01-01

    Side-scan sonar is a valuable tool for mapping habitat features in many aquatic systems suggesting it may also be useful for locating sedentary biota. The objective of this study was to determine if side-scan sonar could be used to identify freshwater mussel (unionid) beds and the required environmental conditions. We used side-scan sonar to develop a series of mussel-bed reference images by placing mussel shells within homogenous areas of fine and coarse substrates. We then used side-scan sonar to map a 32-km river reach during spring and summer. Using our mussel-bed reference images, several river locations were identified where mussel beds appeared to exist in the scanned images and we chose a subset of sites (n = 17) for field validation. The validation confirmed that ~60% of the sites had mussel beds and ~80% had some mussels or shells present. Water depth was significantly related to our ability to predict mussel-bed locations: predictive ability was greatest at depths of 1–2 m, but decreased in water >2-m deep. We determined side-scan sonar is an effective tool for preliminary assessments of mussel presence during times when they are located at or above the substrate surface and in relatively fine substrates excluding fine silt.

  10. Can the elongated hindwing tails of fluttering moths serve as false sonar targets to divert bat attacks?

    PubMed

    Lee, Wu-Jung; Moss, Cynthia F

    2016-05-01

    It has long been postulated that the elongated hindwing tails of many saturniid moths have evolved to create false sonar targets to divert the attack of echolocation-guided bat predators. However, rigorous echo-acoustic evidence to support this hypothesis has been lacking. In this study, fluttering luna moths (Actias luna), a species with elongated hindwing tails, were ensonified with frequency modulated chirp signals from all angles of orientation and across the wingbeat cycle. High-speed stereo videography was combined with pulse compression sonar processing to characterize the echo information available to foraging bats. Contrary to previous suggestions, the results show that the tail echoes are weak and do not dominate the sonar returns, compared to the large, planar wings and the moth body. However, the distinctive twisted morphology of the tails create persistent echoes across all angles of orientation, which may induce erroneous sonar target localization and disrupt accurate tracking by echolocating bats. These findings thus suggest a refinement of the false target hypothesis to emphasize sonar localization errors induced by the twisted tails, and highlight the importance of physics-based approaches to study the sensory information involved in the evolutionary arms race between moths and their bat predators.

  11. Effects of competitive prey capture on flight behavior and sonar beam pattern in paired big brown bats, Eptesicus fuscus.

    PubMed

    Chiu, Chen; Reddy, Puduru Viswanadha; Xian, Wei; Krishnaprasad, Perinkulam S; Moss, Cynthia F

    2010-10-01

    Foraging and flight behavior of echolocating bats were quantitatively analyzed in this study. Paired big brown bats, Eptesicus fuscus, competed for a single food item in a large laboratory flight room. Their sonar beam patterns and flight paths were recorded by a microphone array and two high-speed cameras, respectively. Bats often remained in nearly classical pursuit (CP) states when one bat is following another bat. A follower can detect and anticipate the movement of the leader, while the leader has the advantage of gaining access to the prey first. Bats in the trailing position throughout the trial were more successful in accessing the prey. In this study, bats also used their sonar beam to monitor the conspecific's movement and to track the prey. Each bat tended to use its sonar beam to track the prey when it was closer to the worm than to another bat. The trailing bat often directed its sonar beam toward the leading bat in following flight. When two bats flew towards each other, they tended to direct their sonar beam axes away from each other, presumably to avoid signal jamming. This study provides a new perspective on how echolocating bats use their biosonar system to coordinate their flight with conspecifics in a group and how they compete for the same food source with conspecifics.

  12. Adjustment of Sonar and Laser Acquisition Data for Building the 3D Reference Model of a Canal Tunnel.

    PubMed

    Moisan, Emmanuel; Charbonnier, Pierre; Foucher, Philippe; Grussenmeyer, Pierre; Guillemin, Samuel; Koehl, Mathieu

    2015-12-11

    In this paper, we focus on the construction of a full 3D model of a canal tunnel by combining terrestrial laser (for its above-water part) and sonar (for its underwater part) scans collected from static acquisitions. The modeling of such a structure is challenging because the sonar device is used in a narrow environment that induces many artifacts. Moreover, the location and the orientation of the sonar device are unknown. In our approach, sonar data are first simultaneously denoised and meshed. Then, above- and under-water point clouds are co-registered to generate directly the full 3D model of the canal tunnel. Faced with the lack of overlap between both models, we introduce a robust algorithm that relies on geometrical entities and partially-immersed targets, which are visible in both the laser and sonar point clouds. A full 3D model, visually promising, of the entrance of a canal tunnel is obtained. The analysis of the method raises several improvement directions that will help with obtaining more accurate models, in a more automated way, in the limits of the involved technology.

  13. Adjustment of Sonar and Laser Acquisition Data for Building the 3D Reference Model of a Canal Tunnel †

    PubMed Central

    Moisan, Emmanuel; Charbonnier, Pierre; Foucher, Philippe; Grussenmeyer, Pierre; Guillemin, Samuel; Koehl, Mathieu

    2015-01-01

    In this paper, we focus on the construction of a full 3D model of a canal tunnel by combining terrestrial laser (for its above-water part) and sonar (for its underwater part) scans collected from static acquisitions. The modeling of such a structure is challenging because the sonar device is used in a narrow environment that induces many artifacts. Moreover, the location and the orientation of the sonar device are unknown. In our approach, sonar data are first simultaneously denoised and meshed. Then, above- and under-water point clouds are co-registered to generate directly the full 3D model of the canal tunnel. Faced with the lack of overlap between both models, we introduce a robust algorithm that relies on geometrical entities and partially-immersed targets, which are visible in both the laser and sonar point clouds. A full 3D model, visually promising, of the entrance of a canal tunnel is obtained. The analysis of the method raises several improvement directions that will help with obtaining more accurate models, in a more automated way, in the limits of the involved technology. PMID:26690444

  14. Bottom Characterization with High Resolution Sonar Data and Geochemical Analyses of an Uninvestigated Cone in Lagoa das Furnas on São Miguel Island, Azores Archipelago

    NASA Astrophysics Data System (ADS)

    Andersson, T.

    2015-12-01

    Lagoa das Furnas is a crater lake located in an area exposed to geohazards from earthquakes and volcanic activity on the island São Miguel in the Azores Archipelago. The Furnas volcanic center has a long history of earthquakes and volcanic activity. The area is relatively well studied except for the lake floor. Therefore, a high resolution geophysical and geological mapping survey was conducted at Lagoa das Furnas. Sidescan sonar was used to map the surface of the lake floor and single beam sonar was used to acquire sub-bottom profiles. In addition to the geophysical mapping, sediment surface sampling and core drilling were carried out followed by geochemical analyses of the retrieved material. The mapped data permitted a characterization of the floor of Lagoa das Furnas and revealed several volcanic features including fumarolic activity and a previously uninvestigated volcanic cone in the southern part of the lake. In order to unravel the origin of this cone several methods were applied, including analyses of tephra and minerals collected from the cone itself and from nearby deposits of two known eruptions, Furnas I and Furnas 1630. Sedimentological, petrological, geochemical and geochronological studies of pyroclastic deposits from the cone suggest a subaqueous eruption linked to the Furnas 1630 eruption. The chemistry of glass and crystal fragments sampled from the cone suggests that it is composed of more evolved magma than that of the main Furnas 1630, implying that the lake cone is likely a product of the last eruptional phase. According to historical records, two of three lakes were lost due the Furnas 1630 eruption. The results of this study show that the remaining lake is most likely Lagoa das Furnas, which consequently must have existed before the 1630 eruption.

  15. Relationships between autofocus methods for SAR and self-survey techniques for SONAR. [Synthetic Aperture Radar (SAR)

    SciTech Connect

    Wahl, D.E.; Jakowatz, C.V. Jr.; Ghiglia, D.C.; Eichel, P.H.

    1991-01-01

    Autofocus methods in SAR and self-survey techniques in SONAR have a common mathematical basis in that they both involve estimation and correction of phase errors introduced by sensor position uncertainties. Time delay estimation and correlation methods have been shown to be effective in solving the self-survey problem for towed SONAR arrays. Since it can be shown that platform motion errors introduce similar time-delay estimation problems in SAR imaging, the question arises as to whether such techniques could be effectively employed for autofocus of SAR imagery. With a simple mathematical model for motion errors in SAR, we will show why such correlation/time-delay techniques are not nearly as effective as established SAR autofocus algorithms such as phase gradient autofocus or sub-aperture based methods. This analysis forms an important bridge between signal processing methodologies for SAR and SONAR. 5 refs., 4 figs.

  16. Teaching real-time ultrasonic imaging with a 4-channel sonar array, TI C6711 DSK and MATLAB.

    PubMed

    York, George W P; Welch, Thad B; Wright, Cameron H G

    2005-01-01

    Ultrasonic medical imaging courses often stop at the theory or MATLAB simulation level, since professors find it challenging to give the students the experience of designing a real-time ultrasonic system. Some of the practical problems of working with real-time data from the ultrasonic transducers can be avoided by working at lower frequencies (sonar to low ultrasound) range. To facilitate this, we have created a platform using the ease of MATLAB programming with the real-time processing capability of the low-cost Texas Instruments C6711 DSP starter kit and a 4-channel sonar array. With this platform students can design a B-mode or Color-Mode sonar system in the MATLAB environment. This paper will demonstrate how the platform can be used in the classroom to demonstrate the real-time signal processing stages including beamforming, multi-rate sampling, demodulation, filtering, image processing, echo imaging, and Doppler frequency estimation.

  17. Use of acoustic classification of sidescan sonar data for mapping benthic habitat in the Northern Channel Islands, California

    USGS Publications Warehouse

    Cochrane, Guy R.; Lafferty, Kevin D.

    2002-01-01

    Highly reflective seafloor features imaged by sidescan sonar in nearshore waters off the Northern Channel Islands (California, USA) have been observed in subsequent submersible dives to be areas of thin sand covering bedrock. Adjacent areas of rocky seafloor, suitable as habitat for endangered species of abalone and rockfish, and encrusting organisms, cannot be differentiated from the areas of thin sand on the basis of acoustic backscatter (i.e. grey level) alone. We found second-order textural analysis of sidescan sonar data useful to differentiate the bottom types where data is not degraded by near-range distortion (caused by slant-range and ground-range corrections), and where data is not degraded by far-range signal attenuation. Hand editing based on submersible observations is necessary to completely convert the sidescan sonar image to a bottom character classification map suitable for habitat mapping.

  18. Evaluation of the Performance of Deep Sea Survey Sonars from the Results of Search for a Sunken Ship

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Toshio; Ochi, Hiroshi; Shibata, Jun

    1999-05-01

    The Japan Marine Science & Technology Center carried out a search for the “Tsushima-maru,” a school children evacuation ship which was sunken during the World War II. In this search, we first measured the bottom surface reflection intensity over the entire sea, and narrowed down to a special point using the multi narrow beam echo sounder (SEABEAM 2112.004) equipped to the vessel bottom. Then, the vicinity of the investigated with a towing side scan sonar. Eventually, a TV camera on board an remotely operated vehicle confirming the hull of the ship. The search for the sunken ship was utilized to investigate the performance of the sonars. As a result, resolution and detection abilities of various sonar were confirmed in actual ocean operations.

  19. Navy sonar, cetaceans and the US Supreme Court: a review of cetacean mitigation and litigation in the US.

    PubMed

    Zirbel, K; Balint, P; Parsons, E C M

    2011-01-01

    One source of anthropogenic noise in the oceans which has attracted much concern is naval sonar. As a result of possible impacts of such sonar, several environmental NGOs have pursued legal cases in the United States criticizing environmental assessments conducted prior to exercises and proposed mitigation measures. Cases have been brought using the US National Environmental Protection Act, Marine Mammal Protection Act, Endangered Species Act, Coastal Zone Management Act and other statutes. This paper reviews the chronology and results of these various cases. During the G.W. Bush presidential administration, the legal battle went to the US Supreme Court in the case Winter vs. Natural Resources Defense Council. This case however, did not address the potential impacts of sonar on cetaceans or the effectiveness of mitigation measures. During the Obama administration, mitigation measures for naval exercises have been revised, and working groups planned, in an attempt to resolve conflict between parties.

  20. Technology Infusion of CodeSonar into the Space Network Ground Segment (RII07): Software Assurance Symposium Technical Summary

    NASA Technical Reports Server (NTRS)

    Benson, Markland J.

    2008-01-01

    Presents a source code analysis tool (CodeSonar) for use in the Space Network Ground Segment. The Space Network requires 99.9% proficiency and 97.0% availability of systems. Software has historically accounted for an annual average of 28% of the Space Network loss of availability and proficiency. CSCI A and CSCI B account for 42% of the previous eight months of software data loss. The technology infusion of CodeSonar into the Space Network Ground segment is meant to aid in determining the impact of the technology on the project both in the expenditure of effort and the technical results of the technology. Running a CodeSonar analysis and performing a preliminary review of the results averaged 3.5 minutes per finding (approximately 20 hours total). An additional 40 hours is estimated to analyze the 37 findings deemed too complex for the initial review. Using CodeSonar's tools to suppress known non-problems, delta tool runs will not repeat findings that have been marked as non-problems, further reducing the time needed for review. The 'non-interesting' finding rate of 70% is a large number, but filtering, search, and detailed contextual features of CodeSonar reduce the time per finding. Integration of the tool into the build process may also provide further savings by preventing developers from having to configure and operate the tool separately. These preliminary results show the tool to be easy to use and incorporate into the engineering process. These findings also provide significant potential improvements in proficiency and availability on the part of the software. As time-to-fix data become available a better cost trade can be made on person hours saved versus tool cost. Selective factors may be necessary to determine where best to apply CodeSonar to balance cost and benefits.

  1. Tempo and mode of antibat ultrasound production and sonar jamming in the diverse hawkmoth radiation

    PubMed Central

    Kawahara, Akito Y.; Barber, Jesse R.

    2015-01-01

    The bat–moth arms race has existed for over 60 million y, with moths evolving ultrasonically sensitive ears and ultrasound-producing organs to combat bat predation. The evolution of these defenses has never been thoroughly examined because of limitations in simultaneously conducting behavioral and phylogenetic analyses across an entire group. Hawkmoths include >1,500 species worldwide, some of which produce ultrasound using genital stridulatory structures. However, the function and evolution of this behavior remain largely unknown. We built a comprehensive behavioral dataset of hawkmoth hearing and ultrasonic reply to sonar attack using high-throughput field assays. Nearly half of the species tested (57 of 124 species) produced ultrasound to tactile stimulation or playback of bat echolocation attack. To test the function of ultrasound, we pitted big brown bats (Eptesicus fuscus) against hawkmoths over multiple nights and show that hawkmoths jam bat sonar. Ultrasound production was immediately and consistently effective at thwarting attack and bats regularly performed catching behavior without capturing moths. We also constructed a fossil-calibrated, multigene phylogeny to study the evolutionary history and divergence times of these antibat strategies across the entire family. We show that ultrasound production arose in multiple groups, starting in the late Oligocene (∼26 Ma) after the emergence of insectivorous bats. Sonar jamming and bat-detecting ears arose twice, independently, in the Miocene (18–14 Ma) either from earless hawkmoths that produced ultrasound in response to physical contact only, or from species that did not respond to touch or bat echolocation attack. PMID:25941377

  2. New Mapping of Mariana Submarine Volcanoes with Sidescan and Multibeam Sonars

    NASA Astrophysics Data System (ADS)

    Embley, R. W.; Chadwick, W. W.; Baker, E. T.; Johnson, P. D.; Merle, S. G.; Ristau, S.

    2003-12-01

    An expedition in February/March 2003 on the R/V Thomas G. Thompson mapped more than 18,000 km2 with the towed MR1 sidescan sonar and almost 28,000 km2 with an EM300 hull-mounted multibeam system along the Mariana volcanic arc. The expedition was funded by NOAA's Office of Ocean Exploration (more on the expedition can be found at: http://oceanexplorer.noaa.gov/explorations/03fire/welcome.html). The MR1 sidescan surveys began at the northern end of a 2001 R/V Melville MR1 survey at 16§ N and extended to Nikko Volcano at 23\\deg 05'N. A portion of the southern back-arc spreading center and the arc volcanoes south of 16\\deg N were mapped using the EM300 system. Of 43 submarine arc volcanoes surveyed that have basal diameters of 10 km or greater, 17 have summit calderas or craters. Of these, however, only 5 have diameters more than 2 km. In an accompanying survey of hydrothermal activity along the arc, CTD casts and/or tows were conducted over more than 50 individual volcanoes. The 11 volcanoes with active hydrothermal systems found in the course of these surveys appear to be about equally divided between those with and without summit calderas or craters (for additional information, see Baker et al., Resing et al., and Lupton et al., this session). The flanks of the submarine volcanoes and islands of the central and northern Mariana Arc consist largely of volcaniclastic flows. Most of the larger edifices have high-backscatter spoke-like patterns that probably represent coarser and/or younger flows from the summits. Higher relief high-backscatter areas, also commonly exhibiting a radial pattern, are found on many of the volcanoes' flanks. These are probably lava flows erupted along radial fissures. The Mariana Arc volcanoes are shedding large volumes of volcaniclastic material westward into the back-arc basin through a series of deep-sea channels oriented transverse to the arc that are in many places fed by flows from several volcanoes. On many of the volcaniclastic

  3. Mud volcano field seaward of the Barbados Accretionary Complex: A deep-towed side scan sonar survey

    NASA Astrophysics Data System (ADS)

    Henry, Pierre; Le Pichon, Xavier; Lallemant, Siegfried; Foucher, Jean-Paul; Westbrook, Graham; Hobart, Michael

    1990-06-01

    A 30 km2 diapiric field has been identified near 13°50'N up to 12 km seaward of the deformation front of the Barbados accretionary complex. Using a deep-towed side scan sonar with a 3.5-kHz profiler, we identified 31 different diapiric structures. Based on seismic stratigraphy, we show that this field has been active for 200,000 years and that it is a transient feature triggered by the seaward propagation of the high pore fluid pressure associated with the décollement beneath the accretionary complex. Both basement and décollement in this area are anomalously shallow due to the presence of a N110° basement ridge. The height of the diapirs above seafloor does not exceed 40-50 m and can be related to the pressure head of the mud below the décollement. Two types of structures are identified: mud volcanoes and massively emplaced diapirs and ridges on the one hand, enigmatic circular very flat mud pies and conical mounds on the other hand. The second type of structures has steeper slopes and appears to be associated with very active venting, as confirmed by a submersible exploration reported in a companion paper (Le Pichon et al., this issue (b)). The venting results in the formation of a stiff carbonate crust and of large subsiding basins around the mud pies. Continuous active fluid expulsion through these structures indicates that an efficient piping system still connects them to the zone of anomalously high pore pressure below the protodécollement.

  4. Risk Functions of Dolphins and Sea Lions Exposed to Sonar Signals.

    PubMed

    Houser, Dorian S; Martin, Steven W; Finneran, James J

    2016-01-01

    Acoustic dose-response functions have been recommended as a means of predicting behavioral impacts on marine mammals from anthropogenic noise exposure. Thirty bottlenose dolphins and fifteen sea lions participated in a controlled exposure study to explore dose-response relationships to the received level of a simulated sonar signal. Both species showed an increase in the probability of response and in the severity of response with increased received levels. Differences in species sensitivity were noted in habituation and the impact of age on responsiveness.

  5. Application of high-temperature superconducting wires to magnetostrictive transducers for underwater sonar

    SciTech Connect

    Voccio, J.P.; Joshi, C.H.; Lindberg, J.F.

    1994-07-01

    Recently discovered cryogenic magnetostrictive materials show maximum strains greater than any room temperature materials. These cryogenic magnetostrictors can be combined with high-temperature superconducting (HTS) coils to create a sonar transducer with high efficiency and high acoustic power density. A prototype low-frequency (< 1,000 Hz) magnetostrictive transducer is described. This transducer uses a terbium-dysprosium (TbDy) magnetostrictor rod with HTS coils cooled to 50--80 K using a single-stage cryocooler. The device is designed for operation at water depths of 100 m and is believed to be the first fully integrated prototype demonstration of HTS.

  6. 2000 Multibeam Sonar Survey of Crater Lake, Oregon - Data, GIS, Images, and Movies

    USGS Publications Warehouse

    Gardner, James V.; Dartnell, Peter

    2001-01-01

    In the summer of 2000, the U.S. Geological Survey, Pacific Seafloor Mapping Project in cooperation with the National Park Service, and the Center for Coastal and Ocean Mapping, University of New Hampshire used a state-of-the-art multibeam sonar system to collect high-resolution bathymetry and calibrated, co-registered acoustic backscatter to support both biological and geological research in the Crater Lake area. This interactive CD-ROM contains the multibeam bathymetry and acoustic backscatter data, along with an ESRI ArcExplorer project (and software), images, and movies.

  7. Sampling of Breathable Air in U.S. Navy Sonar Domes

    DTIC Science & Technology

    1994-03-01

    USS Kidd 4/92 154 ( DDG - 993 ) USS Donald B. Beary (FF- 6/92 41 1085) USS Truett 6/92 149 (FF-1095) USS San Jacinto 6/92 70 (CG-56) USS Hue City 9/92 32...pressure-tight bulkhead in the center of the dome. On the DD-963, and DDG - 993 , and CG-47 class ships (i.e., destroyers and 5 cruisers), samples of dome air...Command. NAVSEA S9165-AH-MMA-010. Technical manual for sonar dome rubber window SDRW-1 for DD-963, DDG - 993 , and CG-47 class vessels. Revision 1,

  8. Robust real-time mine classification based on side-scan sonar imagery

    NASA Astrophysics Data System (ADS)

    Bello, Martin G.

    2000-08-01

    We describe here image processing and neural network based algorithms for detection and classification of mines in side-scan sonar imagery, and the results obtained from their application to two distinct image data bases. These algorithms evolved over a period from 1994 to the present, originally at Draper Laboratory, and currently at Alphatech Inc. The mine-detection/classification system is partitioned into an anomaly screening stage followed by a classification stage involving the calculation of features on blobs, and their input into a multilayer perceptron neural network. Particular attention is given to the selection of algorithm parameters, and training data, in order to optimize performance over the aggregate data set.

  9. Ice/berm interaction study using rotary sidescan sonar and acoustic profiling systems

    SciTech Connect

    Good, R.R.; Anderson, K.G.; Lanzier, H.H.

    1984-05-01

    Tarsiut Island, in the Canadian Beaufort Sea, was the first dredged caisson retained island built for exploration drilling operations in the Arctic offshore. Due to the island's configuration location, a large first-year ice rubble pile would result from the ice/structure interaction. This paper outlines how a rotary side-scan sonar and a mechanically scanning, narrow-beam acoustic profiling system were used to determine the geometry and the contact area of the underside of heavily rubbled first-year ice. The results of this study are to be used to further the understanding of the nature and mechanism of the ice/structure interaction in Arctic offshore structures.

  10. Side-scan sonar assessment of gray whale feeding in the Bering Sea

    USGS Publications Warehouse

    Johnson, K.R.; Nelson, C.H.

    1984-01-01

    Side-scan sonar was used to map and measure feeding pits of the California gray whale over 22,000 square kilometers of the northeastern Bering Sea floor. The distribution of pits, feeding whales, ampeliscid amphipods (whale prey), and a fine-sand substrate bearing the amphipods were all closely correlated. The central Chirikov Basin and nearshore areas of Saint Lawrence Island supply at least 6.5 percent of the total gray whale food resource in summer. While feeding, the whales resuspend at least 1.2 x 108 cubic meters of sediment annually; this significantly affects the geology and biology of the region.

  11. Pockmarks, fluid flow, and sediments outboard of the deformation front at the Cascadia Subduction Zone from analysis of multi-channel seismic and multi-beam sonar data

    NASA Astrophysics Data System (ADS)

    Gibson, J. C.; Carbotte, S. M.; Han, S.; Carton, H. D.; Canales, P.; Nedimovic, M. R.

    2013-12-01

    Evidence of active fluid flow and the nature of the sediment section near the Cascadia deformation front are explored using multi-channel (MCS) seismic and multi-beam sonar data collected in summer 2012 using the R/V Marcus G. Langseth during the Juan de Fuca Ridge to Trench Survey. The MCS data were collected along two full plate transects (the 'Oregon' and 'Washington' transects) and one trench parallel line using a 6600 cubic inch source, and an 8 km streamer with 636 channels (12.5 m spacing). The MCS data pre-stack processing sequence includes geometry definition, trace editing, F-K filter, and deconvolution. Velocity analysis is performed via semblance and constant velocity stacks in order to create a velocity model of the sediments and upper oceanic crust. The traces are then stacked, and post-stack time migrated. The sonar data were collected using the R/V Langseth's Kongsberg EM122 1°x1° multi-beam sonar with 288 beams and 432 total soundings across track. Using MB-system the sonar data are cleaned, and the bathymetry data are then gridded at 35 m, while the backscatter data are gridded at 15 m. From the high-resolution mapping data 48 pockmarks varying in diameter from 50 m - 1 km are identified within 60 km outboard of the deformation front. The surface expression of these large features in an area of heavy sedimentation is likely indicative of active fluid flow. In order to gain sub-seafloor perspective on these features the MCS data are draped below the bathymetry/backscatter grids using QPS Fledermaus. From this perspective, specific locations for detailed velocity and attribute analysis of the sediment section are chosen. Sediment velocity and attribute analysis also provide insight into apparent differences in the sediment section and décollement formation along the Oregon and Washington plate transects. While both lines intersect areas of dense pockmark concentration, the area around the Oregon transect has been shown to contain a continuous

  12. Students Soar at DECA's SoNAR Conference

    ERIC Educational Resources Information Center

    Fiscus, Lyn

    2007-01-01

    Career and Technical Student organizations (CTSOs) are an effective mechanism for achieving the goals of education in the 21st century and No Child Left Behind. Through their hands-on approach to learning, CTSOs provide students with many opportunities to become actively involved in their learning and apply classroom knowledge to real-life…

  13. Bats jamming bats: food competition through sonar interference.

    PubMed

    Corcoran, Aaron J; Conner, William E

    2014-11-07

    Communication signals are susceptible to interference ("jamming") from conspecifics and other sources. Many active sensing animals, including bats and electric fish, alter the frequency of their emissions to avoid inadvertent jamming from conspecifics. We demonstrated that echolocating bats adaptively jam conspecifics during competitions for food. Three-dimensional flight path reconstructions and audio-video field recordings of foraging bats (Tadarida brasiliensis) revealed extended interactions in which bats emitted sinusoidal frequency-modulated ultrasonic signals that interfered with the echolocation of conspecifics attacking insect prey. Playbacks of the jamming call, but not of control sounds, caused bats to miss insect targets. This study demonstrates intraspecific food competition through active disruption of a competitor's sensing during food acquisition.

  14. Behavioral responses of California sea lions to mid-frequency (3250-3450 Hz) sonar signals.

    PubMed

    Houser, Dorian S; Martin, Stephen W; Finneran, James J

    2013-12-01

    Military sonar has the potential to negatively impact marine mammals. To investigate factors affecting behavioral disruption in California sea lions (Zalophus californianus), fifteen sea lions participated in a controlled exposure study using a simulated tactical sonar signal (1 s duration, 3250-3450 Hz) as a stimulus. Subjects were placed into groups of three and each group received a stimulus exposure of 125, 140, 155, 170, or 185 dB re: 1 μPa (rms). Each subject was trained to swim across an enclosure, touch a paddle, and return to the start location. Sound exposures occurred at the mid-point of the enclosure. Control and exposure sessions were run consecutively and each consisted of ten, 30-s trials. The occurrence and severity of behavioral responses were used to create acoustic dose-response and dose-severity functions. Age of the subject significantly affected the dose-response relationship, but not the dose-severity relationship. Repetitive exposures did not affect the dose-response relationship.

  15. High resolution mapping and classification of oyster habitats in nearshore Louisiana using sidescan sonar

    USGS Publications Warehouse

    Allen, Y.C.; Wilson, C.A.; Roberts, H.H.; Supan, J.

    2005-01-01

    Sidescan sonar holds great promise as a tool to quantitatively depict the distribution and extent of benthic habitats in Louisiana's turbid estuaries. In this study, we describe an effective protocol for acoustic sampling in this environment. We also compared three methods of classification in detail: mean-based thresholding, supervised, and unsupervised techniques to classify sidescan imagery into categories of mud and shell. Classification results were compared to ground truth results using quadrat and dredge sampling. Supervised classification gave the best overall result (kappa = 75%) when compared to quadrat results. Classification accuracy was less robust when compared to all dredge samples (kappa = 21-56%), but increased greatly (90-100%) when only dredge samples taken from acoustically homogeneous areas were considered. Sidescan sonar when combined with ground truth sampling at an appropriate scale can be effectively used to establish an accurate substrate base map for both research applications and shellfish management. The sidescan imagery presented here also provides, for the first time, a detailed presentation of oyster habitat patchiness and scale in a productive oyster growing area.

  16. Highly Directional Sonar Beam of Narwhals (Monodon monoceros) Measured with a Vertical 16 Hydrophone Array.

    PubMed

    Koblitz, Jens C; Stilz, Peter; Rasmussen, Marianne H; Laidre, Kristin L

    2016-01-01

    Recordings of narwhal (Monodon monoceros) echolocation signals were made using a linear 16 hydrophone array in the pack ice of Baffin Bay, West Greenland in 2013 at eleven sites. An average -3 dB beam width of 5.0° makes the narwhal click the most directional biosonar signal reported for any species to date. The beam shows a dorsal-ventral asymmetry with a narrower beam above the beam axis. This may be an evolutionary advantage for toothed whales to reduce echoes from the water surface or sea ice surface. Source level measurements show narwhal click intensities of up to 222 dB pp re 1 μPa, with a mean apparent source level of 215 dB pp re 1 μPa. During ascents and descents the narwhals perform scanning in the vertical plane with their sonar beam. This study provides valuable information for reference sonar parameters of narwhals and for the use of acoustic monitoring in the Arctic.

  17. Autofocusing circular synthetic aperture sonar imagery using phase corrections modeled as generalized cones.

    PubMed

    Marston, Timothy M; Kennedy, Jermaine L; Marston, Philip L

    2014-08-01

    Circular synthetic aperture sonar (CSAS) is a coherent aperture synthesis technique that utilizes backscattered acoustic information from an encircled scene to generate information rich, high-resolution imagery. The aperture length required for image synthesis is much longer than in its linear synthetic aperture sonar counterpart and can result in challenging phase delay and navigation estimation constraints. Residual uncorrected phase errors manifest as focus aberrations in reconstructed CSAS imagery. This paper demonstrates that phase error in image patches can be approximated as an aspect variant linear phase shift representable as a generalized cone in wave-number space. If the geometry of the generalized cone is known, it can be applied as the spectral phase of an inverse filter for aberration correction. A method is derived for reconstructing the error cone geometry from independent estimates of its local curvatures, which are found via a series of one-dimensional line searches that maximize the focus of CSAS sub-aperture images. This approach is applied to real and simulated CSAS data containing aperture distortions, and the results successfully demonstrate estimation and correction of the underlying focus aberrations.

  18. Wall-Corner Classification Using Sonar: A New Approach Based on Geometric Features

    PubMed Central

    Martínez, Milagros; Benet, Ginés

    2010-01-01

    Ultrasonic signals coming from rotary sonar sensors in a robot gives us several features about the environment. This enables us to locate and classify the objects in the scenario of the robot. Each object and reflector produces a series of peaks in the amplitude of the signal. The radial and angular position of the sonar sensor gives information about location and their amplitudes offer information about the nature of the surface. Early works showed that the amplitude can be modeled and used to classify objects with very good results at short distances—80% average success in classifying both walls and corners at distances less than 1.5 m. In this paper, a new set of geometric features derived from the amplitude analysis of the echo is presented. These features constitute a set of characteristics that can be used to improve the results of classification at distances from 1.5 m to 4 m. Also, a comparative study on classification algorithms widely used in pattern recognition techniques has been carried out for sensor distances ranging between 0.5 to 4 m, and with incidence angles ranging between 20° to 70°. Experimental results show an enhancement on the success in classification rates when these geometric features are considered. PMID:22163493

  19. Sidescan sonar as a tool for detection of demersal fish habitats

    USGS Publications Warehouse

    Able, Kenneth W.; Twichell, David C.; Grimes, Churchill B.; Jones, R. S.

    1987-01-01

    Sidescan sonar can be an effective tool for the determination of the habitat distribution of commercially important species.  This technique has the advantage of rapidly mapping large areas of the seafloor.  Sidescan images (sonographs) may also help to identify appropriate fishing gears for different types of seafloor or areas to be avoided with certain types of gears.  During the early stages of exploration, verification of sidescan sonar sonographs is critical to successful identification of important habitats.  Tilefishes (Lopholatilus and Caulolatilus) are especially good target species because the construct large burrows in the seafloor or live around boulders, both of which are easily detectable on sonographs.  In some special circumstances the estimates of tilefish burrow densities from sonographs can be used to estimate standing stock. In many localities the burrow and boulder habitats of tilefish are shared with other commercially important species such as American lobsters, Homarus americanus; cusk, Brosme brosme; and ocean pout, Macrozoarces americanus.

  20. Echolocation with bat buzz emissions: model and biomimetic sonar for elevation estimation.

    PubMed

    Kuc, Roman

    2012-01-01

    Just prior to capture the Buzz II emissions of some mouth-emitting bats, such as Eptesicus fuscus, are observed to exhibit spectra having multiple peaks. This paper proposes an echolocation strategy that uses such spectra with energy concentrated in specific frequency bands for determining target elevation. A biomimetic sonar was implemented to produce a tri-modal spectrum by driving a speaker with a signal rich in harmonics. The emission magnitudes at these harmonic frequencies measured as a function of elevation in the zero-azimuth plane form distinct beams. A template was formed from the ratio of the first harmonic and fundamental magnitudes to determine elevation. The elevation estimator exhibited a sub-degree accuracy (SD = 0.4° over a 20° interval centered at the elevation at which these two beams intersect in the zero-azimuth plane. Spectral cues from -40° to +10° elevation allow a qualitative non-linear control of sonar orientation to drive the target to the beam-intersection point where quantitative elevation estimates are available.

  1. Rifting and volcanism on the ocean floor from high resolution bathymetry and sonar backscatter data

    SciTech Connect

    Arvidson, R.E.; Edwards, M.; Batiza, R.

    1985-01-01

    The authors have recently compiled a global shaded relief map that has roughly 10 x 10 km spatial resolution, using 4 separate digital data sets. This global data set delineates many longer wavelength features such as trenches, ridges, and topographic swells related to hot spots. The map also provides a regional bathymetric context for interpreting, for example, the new multichannel SEABEAM bathymetric data, which have lateral resolutions of several hundred meters and a vertical resolution measured in meters. They have processed a number of SEABEAM data sets acquired for seamounts, overlapping spreading centers, and propagating fractures. Contour maps cannot readily display all the bathymetric detail in these data. Thus, the 16 channel data were converted to shaded-relief images and color composites to preserve and meaningfully display the bathymetric details. SEAMARC sonar backscatter images, where available, were geometrically registered to the SEABWAM data for direct comparison of sonar reflectivity and roughness with depth and slope. The processed data are now being analyzed as part of tectonic and volcanic studies at a half dozen institutions. The project clearly demonstrates the synergistic effects to be gained by crossing disciplines when similar approaches can be used to advantage.

  2. Highly Directional Sonar Beam of Narwhals (Monodon monoceros) Measured with a Vertical 16 Hydrophone Array

    PubMed Central

    Koblitz, Jens C.; Stilz, Peter; Rasmussen, Marianne H.; Laidre, Kristin L.

    2016-01-01

    Recordings of narwhal (Monodon monoceros) echolocation signals were made using a linear 16 hydrophone array in the pack ice of Baffin Bay, West Greenland in 2013 at eleven sites. An average -3 dB beam width of 5.0° makes the narwhal click the most directional biosonar signal reported for any species to date. The beam shows a dorsal-ventral asymmetry with a narrower beam above the beam axis. This may be an evolutionary advantage for toothed whales to reduce echoes from the water surface or sea ice surface. Source level measurements show narwhal click intensities of up to 222 dB pp re 1 μPa, with a mean apparent source level of 215 dB pp re 1 μPa. During ascents and descents the narwhals perform scanning in the vertical plane with their sonar beam. This study provides valuable information for reference sonar parameters of narwhals and for the use of acoustic monitoring in the Arctic. PMID:27828956

  3. Investigation of sonar transponders for offshore wind farms: modeling approach, experimental setup, and results.

    PubMed

    Fricke, Moritz B; Rolfes, Raimund

    2013-11-01

    The installation of offshore wind farms in the German Exclusive Economic Zone requires the deployment of sonar transponders to prevent collisions with submarines. The general requirements for these systems have been previously worked out by the Research Department for Underwater Acoustics and Marine Geophysics of the Bundeswehr. In this article, the major results of the research project "Investigation of Sonar Transponders for Offshore Wind Farms" are presented. For theoretical investigations a hybrid approach was implemented using the boundary element method to calculate the source directivity and a three-dimensional ray-tracing algorithm to estimate the transmission loss. The angle-dependence of the sound field as well as the weather-dependence of the transmission loss are compared to experimental results gathered at the offshore wind farm alpha ventus, located 45 km north of the island Borkum. While theoretical and experimental results are in general agreement, the implemented model slightly underestimates scattering at the rough sea surface. It is found that the source level of 200 dB re 1 μPa at 1 m is adequate to satisfy the detectability of the warning sequence at distances up to 2 NM (≈3.7 km) within a horizontal sector of ±60° if realistic assumptions about signal-processing and noise are made. An arrangement to enlarge the angular coverage is discussed.

  4. Assessment of a Static Multibeam Sonar Scanner for 3d Surveying in Confined Subaquatic Environments

    NASA Astrophysics Data System (ADS)

    Moisan, E.; Charbonnier, P.; Foucher, P.; Grussenmeyer, P.; Guillemin, S.; Samat, O.; Pagès, C.

    2016-06-01

    Mechanical Scanning Sonar (MSS) is a promising technology for surveying underwater environments. Such devices are comprised of a multibeam echosounder attached to a pan & tilt positioner, that allows sweeping the scene in a similar way as Terrestrial Laser Scanners (TLS). In this paper, we report on the experimental assessment of a recent MSS, namely, the BlueView BV5000, in a confined environment: lock number 50 on the Marne-Rhin canal (France). To this aim, we hung the system upside-down to scan the lock chamber from the surface, which allows surveying the scanning positions, up to an horizontal orientation. We propose a geometric method to estimate the remaining angle and register the scans in a coordinate system attached to the site. After reviewing the different errors that impair sonar data, we compare the resulting point cloud to a TLS model that was acquired the day before, while the lock was completely empty for maintenance. While the results exhibit a bias that can be partly explained by an imperfect setup, the maximum difference is less than 15 cm, and the standard deviation is about 3.5 cm. Visual inspection shows that coarse defects of the masonry, such as stone lacks or cavities, can be detected in the MSS point cloud, while smaller details, e.g. damaged joints, are harder to notice.

  5. Echoview as a multibeam sonar data processing and analysis toolkit for fisheries research

    NASA Astrophysics Data System (ADS)

    Buelens, Bart; Pauly, Tim; Higginbottom, Ian

    2003-10-01

    Echoview is a hydroacoustic data analysis software package, widely used in the fisheries research and stock assessment communities. Originally developed to handle a variety of single-beam sonar data formats, Echoview has been extended to support multibeam data. Multibeam data logging, lossless compression, and real time beamforming and display are some of the software's core features. Multibeam data has an additional dimension compared to single-beam data, and a 3D data viewer has been developed providing 3D visualizations of the seabed and fish schools detected by built-in algorithms. Since the multibeam module is just one of many software modules of the Echoview package, data from other sources such as single-beam sonar systems and current profilers can be combined and analyzed together with the multibeam data. The combination of coincident fish density estimates from calibrated single-beam backscatter data with school volume estimates from multibeam data will represent a significant improvement in stock assessment methods. Ongoing research and development will make it possible for Echoview to follow and even set new trends in multibeam water-column data analysis for fisheries research. Features under development include calibration, vessel motion compensation, improved feature detection, and enhanced and animated 3D displays.

  6. Seafloor habitat mapping of the New York Bight incorporating sidescan sonar data

    USGS Publications Warehouse

    Lathrop, R.G.; Cole, M.; Senyk, N.; Butman, B.

    2006-01-01

    The efficacy of using sidescan sonar imagery, image classification algorithms and geographic information system (GIS) techniques to characterize the seafloor bottom of the New York Bight were assessed. The resulting seafloor bottom type map was compared with fish trawl survey data to determine whether there were any discernable habitat associations. An unsupervised classification with 20 spectral classes was produced using the sidescan sonar imagery, bathymetry and secondarily derived spatial heterogeneity to characterize homogenous regions within the study area. The spectral classes, geologic interpretations of the study region, bathymetry and a bottom landform index were used to produce a seafloor bottom type map of 9 different bottom types. Examination of sediment sample data by bottom type indicated that each bottom type class had a distinct composition of sediments. Analysis of adult summer flounder, Paralichthys dentatus, and adult silver hake, Merluccius bilinearis, presence/absence data from trawl surveys did not show evidence of strong associations between the species distributions and seafloor bottom type. However, the absence of strong habitat associations may be more attributable to the coarse scale and geographic uncertainty of the trawl sampling data than conclusive evidence that no habitat associations exist for these two species. ?? 2006 Elsevier Ltd. All rights reserved.

  7. Dynamic response of an insonified sonar window interacting with a Tonpilz transducer array.

    PubMed

    Hull, Andrew J

    2007-08-01

    This paper derives and evaluates an analytical model of an insonified sonar window in contact with an array of Tonpilz transducers operating in receive mode. The window is fully elastic so that all wave components are present in the analysis. The output of the model is a transfer function of a transducer element output voltage divided by input pressure versus arrival angle and frequency. This model is intended for analysis of sonar systems that are to be built or modified for broadband processing. The model is validated at low frequency with a comparison to a previously derived thin plate model. Once this is done, an example problem is studied so that the effects of higher order wave interaction with acoustic reception can be understood. It was found that these higher order waves cause multiple nulls in the region where the array detects acoustic energy and that their locations in the arrival angle-frequency plane can be determined. The effects of these nulls in the beam patterns of the array are demonstrated.

  8. Design of a multi-sensor sonar system for indoor range measurement as a navigational aid for the blind.

    PubMed

    Choudhury, Maroof H; Barreto, Armando

    2003-01-01

    This paper reports the methodology for the design of a sonar-based ranging and guidance system. The intended application of the system is to help a blind person avoid obstacles as he/she navigates his/her environment. Six sonar transceivers are arranged radially on a headgear worn by the user. The transceivers detect discrete range data at discrete-time sampling instances. A panoramic map of the environment is generated from the discrete-space sensory data. The paper emphasizes the challenges faced during the measurement of omnidirectional ranging information in indoor environments. Situations have been identified where erroneous range readings are generated due to channel cross talk caused by echo bouncing off multiple surfaces. Several sonar control and measurement schemes were developed and tested to avoid these situations. The results and performance of these different control schemes are compared in this paper. A microcontroller-based system commands the sonar ping sequences, acquires the echo return times and computes the ranges. The set of range data is transmitted to a PC, which utilizes the information to build a spatialized audio map of the surrounding obstacles. The hardware and software layout for the system are described in this paper.

  9. A New Multibeam Sonar Technique for Evaluating Fine-Scale Fish Behavior Near Hydroelectric Dam Guidance Structures

    SciTech Connect

    Johnson, Robert L.; Simmons, Mary Ann; Simmons, Carver S.; Blanton, Susan L.; Coutant, C.

    2002-03-07

    This book chapter describes a Dual-Head Multibeam Sonar (DHMS) system developed by Battelle and deployed at two dam sites on the Snake and Columbia rivers in Washington State to evaluate the fine-scale (

  10. Improvement of energy efficiency via spectrum optimization of excitation sequence for multichannel simultaneously triggered airborne sonar system.

    PubMed

    Meng, Qing-Hao; Yao, Zhen-Jing; Peng, Han-Yang

    2009-12-01

    Both the energy efficiency and correlation characteristics are important in airborne sonar systems to realize multichannel ultrasonic transducers working together. High energy efficiency can increase echo energy and measurement range, and sharp autocorrelation and flat cross correlation can help eliminate cross-talk among multichannel transducers. This paper addresses energy efficiency optimization under the premise that cross-talk between different sonar transducers can be avoided. The nondominated sorting genetic algorithm-II is applied to optimize both the spectrum and correlation characteristics of the excitation sequence. The central idea of the spectrum optimization is to distribute most of the energy of the excitation sequence within the frequency band of the sonar transducer; thus, less energy is filtered out by the transducers. Real experiments show that a sonar system consisting of eight-channel Polaroid 600 series electrostatic transducers excited with 2 ms optimized pulse-position-modulation sequences can work together without cross-talk and can measure distances up to 650 cm with maximal 1% relative error.

  11. Side-scan sonar and submersible observations: New techniques for gleaning more information from sea-floor outcrops

    SciTech Connect

    Kendall, J.; Hams, J.E.; Buck, S.P. )

    1990-05-01

    Advances in high resolution side-scan sonar imaging technology are so effective at imaging sea-floor geology that they have greatly improved the efficiency of a bottom sampling program The traditional sea-floor geology methodology of shooting a high-resolution seismic survey and sampling along the seismic grid was considered successful if outcrops were sampled on 20% of the attempts. A submersible was used sparingly because of the inability to consistently locate sea-floor outcrops. Side-scan sonar images have increased the sampling success ratio to 70-95% and allow the cost-effective use of a submersible even in areas of sparse sea-floor outcrops. In offshore basins this new technology has been used in consolidated and semiconsolidated rock terranes. When combined with observations from a two-man submersible, SCUBA traverses, seismic data, and traditional sea-floor bottom sampling techniques, enough data are provided to develop an integrated sea-floor geologic interpretation. On individual prospects, side-scan sonar has aided the establishment of critical dip in poor seismic data areas, located seeps and tar mounds, and determined erosional breaching of a prospect. Over a mature producing field, side-scan sonar has influenced the search for field extension by documenting the orientation and location of critical trapping cross faults. These relatively inexpensive techniques can provide critical data in any marine basin where rocks crop out on the sea floor.

  12. Dose-response relationships for the onset of avoidance of sonar by free-ranging killer whales.

    PubMed

    Miller, Patrick J O; Antunes, Ricardo N; Wensveen, Paul J; Samarra, Filipa I P; Alves, Ana Catarina; Tyack, Peter L; Kvadsheim, Petter H; Kleivane, Lars; Lam, Frans-Peter A; Ainslie, Michael A; Thomas, Len

    2014-02-01

    Eight experimentally controlled exposures to 1-2 kHz or 6-7 kHz sonar signals were conducted with four killer whale groups. The source level and proximity of the source were increased during each exposure in order to reveal response thresholds. Detailed inspection of movements during each exposure session revealed sustained changes in speed and travel direction judged to be avoidance responses during six of eight sessions. Following methods developed for Phase-I clinical trials in human medicine, response thresholds ranging from 94 to 164 dB re 1 μPa received sound pressure level (SPL) were fitted to Bayesian dose-response functions. Thresholds did not consistently differ by sonar frequency or whether a group had previously been exposed, with a mean SPL response threshold of 142 ± 15 dB (mean ± s.d.). High levels of between- and within-individual variability were identified, indicating that thresholds depended upon other undefined contextual variables. The dose-response functions indicate that some killer whales started to avoid sonar at received SPL below thresholds assumed by the U.S. Navy. The predicted extent of habitat over which avoidance reactions occur depends upon whether whales responded to proximity or received SPL of the sonar or both, but was large enough to raise concerns about biological consequences to the whales.

  13. Using side-scan sonar to characterize and map physical habitat and anthropogenic underwater features in the St. Louis River.

    EPA Science Inventory

    Characterizing underwater habitat and other features is difficult and costly, especially in the large St. Louis River Estuary. We are using side-scan sonar (SSS), first developed in the 1960s to remotely sense underwater habitat features from reflected acoustic signals (backscatt...

  14. Cumulative Track-Initiation Probability as a Basis for Assessing Sonar-System Performance in Anti-Submarine Warfare

    DTIC Science & Technology

    2009-12-01

    one sonar mode.(e) The scenario should start at a range Rinitial where the single-ping pd values are negligibly small.(f) That is, pd values as a...1). (2) With the initial value of Pd,1 = pd,1. Ping 1 is the first ping following scenario start at range Rinitial . At each subsequent ping

  15. Neural mechanisms underlying the analysis of sonar and social vocalizations: Spectral and temporal integration in the mustached bat

    NASA Astrophysics Data System (ADS)

    Wenstrup, Jeffrey J.; Nataraj, Kiran; Gans, Don; Sheykholeslami, Kianoush

    2004-05-01

    The analysis of sonar echoes by the mustached bat depends on combination-sensitive neurons that respond best when distinct spectral elements of a sonar pulse and echo occur in a particular temporal relationship. Such integrative response properties underlie direct comparisons of acoustic features in outgoing pulses and returning echoes, comparisons thought to encode pulse-echo delay and other information-bearing features of echoes. These response properties are abundant in the auditory midbrain, thalamus, and cortex of the mustached bat. Combination-sensitive neurons utilize facilitatory and inhibitory neural interactions to create selective responses to acoustic features. The different interactions (facilitatory and inhibitory) originate in different stages within the ascending auditory pathway. Inhibitory interactions arise mostly in the auditory brainstem. Facilitatory interactions arise within the inferior colliculus, but also display the results of the inhibitory interactions originating at brainstem levels. These response properties are well suited to the analysis of sonar echoes, but similar combinatorial response properties are tuned to spectral elements outside sonar frequency bands, probably to elements of social vocalizations. It is therefore likely that the neural analysis of biosonar signals shares common features with the analysis of other vocal signals. [Work supported by the National Institute on Deafness and Other Communication Disorders.

  16. A Synthesis of Multibeam Bathymetry and Backscatter, and Sidescan Sonar of the Mariana Submarine Magmatic Arc, Western Pacific

    NASA Astrophysics Data System (ADS)

    Embley, R. W.; Chadwick, W. W.; Stern, R. J.; Merle, S. G.; Bloomer, S. H.; Nakamura, K.; Tamura, Y.

    2006-12-01

    A series of expeditions funded by the NSF MARGINS Program, the NOAA Ocean Exploration Program and JAMSTEC from 2001 to 2006 have collected a large data set that includes multibeam bathymetry and backscatter and surface-towed MR-1 sidescan sonar along more than 1200 km of the Mariana submarine magmatic arc between 12 and 23 degrees N. These data, along with more limited in situ observational data from remotely operated vehicle dives, are interpreted within an ESRI ArcGIS framework to produce a series of preliminary geologic maps showing a wide range of volcanic, tectonic and other morphologic features along the arc. The maps reveal a widespread channelized distribution of volcaniclastic material from volcanoes in the Southern Seamount Province (SSP) and Central Island Provinces (CIP). Giant sediment wave forms (up to 2 km in wavelength) occur on the flanks of many of the volcanoes and can be traced out to up to 60 km (Esmeralda). Relative ages of the activity of the volcanoes can be assigned in some areas where deposits from one edifice overlap others or where erosion has deeply dissected the flanks. Faulting is common on the frontal arc, especially in the SSP and the Northern Seamount Province (NSP). Many of the individual volcanoes have faults that are oriented at a range of azimuths but are commonly at either an arc-parallel or arc- orthogonal orientations. Several large extensional basins (>30 across in arc-parallel direction) occur in the NSP. One of these features exhibits a zone of headless channels on its western flank, implying that the feature may be a very large caldera.

  17. 50 CFR 216.174 - Mitigation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... extent possible consistent with safety of the ship. (xv) All personnel engaged in passive acoustic sonar... of acoustic/explosive sources, direction and speed of units using MFAS, and marine mammal sightings... direction and are dictated by environmental and other conditions (e.g., safety, weather). (2) Mitigation...

  18. 50 CFR 216.174 - Mitigation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... extent possible consistent with safety of the ship. (xv) All personnel engaged in passive acoustic sonar... of acoustic/explosive sources, direction and speed of units using MFAS, and marine mammal sightings... direction and are dictated by environmental and other conditions (e.g., safety, weather). (2) Mitigation...

  19. 50 CFR 216.174 - Mitigation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... extent possible consistent with safety of the ship. (xv) All personnel engaged in passive acoustic sonar... of acoustic/explosive sources, direction and speed of units using MFAS, and marine mammal sightings... direction and are dictated by environmental and other conditions (e.g., safety, weather). (2) Mitigation...

  20. 50 CFR 216.174 - Mitigation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... extent possible consistent with safety of the ship. (xv) All personnel engaged in passive acoustic sonar... of acoustic/explosive sources, direction and speed of units using MFAS, and marine mammal sightings... direction and are dictated by environmental and other conditions (e.g., safety, weather). (2) Mitigation...

  1. Public awareness and attitudes towards naval sonar mitigation for cetacean conservation: a preliminary case study in Fairfax County, Virginia. (the DC Metro area).

    PubMed

    Zirbel, K; Balint, P; Parsons, E C M

    2011-01-01

    The potential impacts of naval sonar on cetaceans has led to a series of court cases and statements of concern by international organizations. However, there has been no research conducted on attitudes of the general public with respect to this issue. To investigate this, a preliminary public survey was conducted in Fairfax, Virginia (the Washington, DC Metro region). The majority of the public sampled believed that naval sonar impacted marine mammals (51.3%), that the US Navy should not be exempt from environmental regulations in time of peace (75.2%), and that sonar use should be moderated if it impacts cetaceans (75.8%). Individuals who were conservative, Republican, and have served in the military were more likely to believe the Navy should be exempt from marine mammal protection regulations. In addition, expert interviews were conducted to gain opinions on the potential ramifications of the recent US Supreme Court case on naval sonar mitigation.

  2. Treatment of systematic errors in the processing of wide angle sonar sensor data for robotic navigation

    SciTech Connect

    Beckerman, M.; Oblow, E.M.

    1988-04-01

    A methodology has been developed for the treatment of systematic errors which arise in the processing of sparse sensor data. We present a detailed application of this methodology to the construction from wide-angle sonar sensor data of navigation maps for use in autonomous robotic navigation. In the methodology we introduce a four-valued labelling scheme and a simple logic for label combination. The four labels, conflict, occupied, empty and unknown, are used to mark the cells of the navigation maps; the logic allows for the rapid updating of these maps as new information is acquired. The systematic errors are treated by relabelling conflicting pixel assignments. Most of the new labels are obtained from analyses of the characteristic patterns of conflict which arise during the information processing. The remaining labels are determined by imposing an elementary consistent-labelling condition. 26 refs., 9 figs.

  3. Signal classification using global dynamical models, Part II: SONAR data analysis

    SciTech Connect

    Kremliovsky, M.; Kadtke, J.

    1996-06-01

    In Part I of this paper, we described a numerical method for nonlinear signal detection and classification which made use of techniques borrowed from dynamical systems theory. Here in Part II of the paper, we will describe an example of data analysis using this method, for data consisting of open ocean acoustic (SONAR) recordings of marine mammal transients, supplied from NUWC sources. The purpose here is two-fold: first to give a more operational description of the technique and provide rules-of-thumb for parameter choices; and second to discuss some new issues raised by the analysis of non-ideal (real-world) data sets. The particular data set considered here is quite non-stationary, relatively noisy, is not clearly localized in the background, and as such provides a difficult challenge for most detection/classification schemes. {copyright} {ital 1996 American Institute of Physics.}

  4. Quantifying Fish Backscattering using SONAR Instrument and Kirchhoff Ray Mode (KRM) Model

    NASA Astrophysics Data System (ADS)

    Manik, Henry M.

    2016-08-01

    Sonar instrument was used to study backscattering from tuna fish. Extraction of target strength, incidence angle, and frequency dependence of the backscattered signal for individual scatterer was important for biological information. For this purpose, acoustic measurement of fish backscatter was conducted in the laboratory. Characteristics and general trends of the target strength of fish with special reference to tuna fish were investigated by using a Kirchhoff Ray Mode (KRM) model. Backscattering strength were calculated for the KRM having typical morphological and physical parameters of actual fish. Those backscattering amplitudes were shown as frequency, body length, backscattering patterns, the density and sound speed dependences, and orientation dependence. These results were compared with experimentally measured target strength data and good agreement was found. Measurement and model showed the target strength from the fish are depend on the presence of swimbladder. Target Strength increase with increasing the frequency and fish length.

  5. Optimization of Adaboost Algorithm for Sonar Target Detection in a Multi-Stage ATR System

    NASA Technical Reports Server (NTRS)

    Lin, Tsung Han (Hank)

    2011-01-01

    JPL has developed a multi-stage Automated Target Recognition (ATR) system to locate objects in images. First, input images are preprocessed and sent to a Grayscale Optical Correlator (GOC) filter to identify possible regions-of-interest (ROIs). Second, feature extraction operations are performed using Texton filters and Principal Component Analysis (PCA). Finally, the features are fed to a classifier, to identify ROIs that contain the targets. Previous work used the Feed-forward Back-propagation Neural Network for classification. In this project we investigate a version of Adaboost as a classifier for comparison. The version we used is known as GentleBoost. We used the boosted decision tree as the weak classifier. We have tested our ATR system against real-world sonar images using the Adaboost approach. Results indicate an improvement in performance over a single Neural Network design.

  6. Method for shaping and aiming narrow beams. [sonar mapping and target identification

    NASA Technical Reports Server (NTRS)

    Heyser, R. C. (Inventor)

    1981-01-01

    A sonar method and apparatus is discribed which utilizes a linear frequency chirp in a transmitter/receiver having a correlator to synthesize a narrow beamwidth pattern from otherwise broadbeam transducers when there is relative velocity between the transmitter/receiver and the target. The chirp is so produced in a generator in bandwidth, B, and time, T, as to produce a time bandwidth product, TB, that is increased for a narrower angle. A replica of the chirp produced in a generator is time delayed and Doppler shifted for use as a reference in the receiver for correlation of received chirps from targets. This reference is Doppler shifted to select targets preferentially, thereby to not only synthesize a narrow beam but also aim the beam in azimuth and elevation.

  7. Speed Control of a Sonar-Based Mobile Robot by Considering the Limitation of Accelerated Velocity

    NASA Astrophysics Data System (ADS)

    Emaru, Takanori; Hoshino, Yohei; Kobayashi, Yukinori

    In an autonomous mobile robot, ultrasonic time-of-flight (TOF) ranging systems are widely used for distance measurements. However, ultrasonic TOF ranging systems tend to neglect infinitesimal reflected waves below a threshold level. Therefore, we have proposed an integration-type ultrasonic wave sensor that utilizes the integration value of the sonar's reflected wave to recognize a traversable area for an autonomous mobile robot. The proposed method simultaneously determines the path and velocity; however, the calculated velocity varies significantly because of sensor noise or error. This paper presents a novel approach to filter the velocity by considering the accelerated velocity. This enables us to consider the limitation of the force exerted by the robot. The validity of the proposed method is investigated in various environments by applying this method to an autonomous mobile robot.

  8. Acoustic Image Models for Obstacle Avoidance with Forward-Looking Sonar

    NASA Astrophysics Data System (ADS)

    Masek, T.; Kölsch, M.

    Long-range forward-looking sonars (FLS) have recently been deployed in autonomous unmanned vehicles (AUV). We present models for various features in acoustic images, with the goal of using this sensor for altitude maintenance, obstacle detection and obstacle avoidance. First, we model the backscatter and FLS noise as pixel-based, spatially-varying intensity distributions. Experiments show that these models predict noise with an accuracy of over 98%. Next, the presence of acoustic noise from two other sources including a modem is reliably detected with a template-based filter and a threshold learned from training data. Lastly, the ocean floor location and orientation is estimated with a gradient-descent method using a site-independent template, yielding sufficiently accurate results in 95% of the frames. Temporal information is expected to further improve the performance.

  9. Surficial geology in central Narragansett Bay, Rhode Island: interpretations of sidescan sonar and multibeam bathymetry

    USGS Publications Warehouse

    McMullen, Katherine Y.; Poppe, Larry J.; Signell, Richard P.; Denny, Jane F.; Crocker, Jim M.; Beaver, Andrew L.; Schattgen, P. Tod

    2006-01-01

    The United States Geological Survey (USGS) is working cooperatively with the National Oceanic and Atmospheric Association (NOAA) to interpret the surficial geology in estuaries along the coast of the northeastern United States. The purpose of our present study is to determine the distributions of surficial sediments and sedimentary environments in two areas of Narragansett Bay, Rhode Island, using sidescan sonar imagery, high-resolution bathymetry, and sediment data. This study provides a framework for future studies on topics such as benthic habitats and oceanographic processes that control the transport and distribution of bottom sediments. This study mapped two separate areas totalling about 33 km² One area lies in West Passage between Plum Point, Quonset Point and Conanicut Island; the other area lies in East Passage around Dyer Island and extends south of Prudence Island

  10. Sidescan sonar examination of deteriorated revetments and bulkheads along Chicago's lake front

    USGS Publications Warehouse

    Chrzastowski, Michael J.

    1989-01-01

    Lakefill for parks along Chicago's lake front is primarily defended with aged, deteriorated revetments. Survey by 100- and 500-kHz sidescan sonar documents that structural failure of the revetments is not related to lake-bottom undermining. The size and weight of the rock fill in the cribs is identified as a critical factor. Long-term effects of wave surge combined with ice action and gravity can remove rock fill either through breaks in the timber crib wall, or where revetment design offers lakeward exposure of the rock fill. Capstones are displaced when they lose underlying support. Revetments with a lakeward face of steel sheetpile, or toe protection mounded high against the structure, have no significant capstone displacement and are models for improved design. This study supports a rebuilding project that will bury the old revetments with new structures having a lakeward face of either steel sheetpile or a rubble mound.

  11. Signal classification using global dynamical models, Part II: SONAR data analysis

    NASA Astrophysics Data System (ADS)

    Kremliovsky, Michael; Kadtke, James

    1996-06-01

    In Part I of this paper, we described a numerical method for nonlinear signal detection and classification which made use of techniques borrowed from dynamical systems theory. Here in Part II of the paper, we will describe an example of data analysis using this method, for data consisting of open ocean acoustic (SONAR) recordings of marine mammal transients, supplied from NUWC sources. The purpose here is two-fold: first to give a more operational description of the technique and provide rules-of-thumb for parameter choices; and second to discuss some new issues raised by the analysis of non-ideal (real-world) data sets. The particular data set considered here is quite non-stationary, relatively noisy, is not clearly localized in the background, and as such provides a difficult challenge for most detection/classification schemes.

  12. Seafloor identification in sonar imagery via simulations of Helmholtz equations and discrete optimization

    NASA Astrophysics Data System (ADS)

    Engquist, Björn; Frederick, Christina; Huynh, Quyen; Zhou, Haomin

    2017-06-01

    We present a multiscale approach for identifying features in ocean beds by solving inverse problems in high frequency seafloor acoustics. The setting is based on Sound Navigation And Ranging (SONAR) imaging used in scientific, commercial, and military applications. The forward model incorporates multiscale simulations, by coupling Helmholtz equations and geometrical optics for a wide range of spatial scales in the seafloor geometry. This allows for detailed recovery of seafloor parameters including material type. Simulated backscattered data is generated using numerical microlocal analysis techniques. In order to lower the computational cost of the large-scale simulations in the inversion process, we take advantage of a pre-computed library of representative acoustic responses from various seafloor parameterizations.

  13. Using Data Crawlers and Semantic Web to Build Financial XBRL Data Generators: The SONAR Extension Approach

    PubMed Central

    Rodríguez-García, Miguel Ángel; Rodríguez-González, Alejandro; Valencia-García, Rafael; Gómez-Berbís, Juan Miguel

    2014-01-01

    Precise, reliable and real-time financial information is critical for added-value financial services after the economic turmoil from which markets are still struggling to recover. Since the Web has become the most significant data source, intelligent crawlers based on Semantic Technologies have become trailblazers in the search of knowledge combining natural language processing and ontology engineering techniques. In this paper, we present the SONAR extension approach, which will leverage the potential of knowledge representation by extracting, managing, and turning scarce and disperse financial information into well-classified, structured, and widely used XBRL format-oriented knowledge, strongly supported by a proof-of-concept implementation and a thorough evaluation of the benefits of the approach. PMID:24587726

  14. Using data crawlers and semantic Web to build financial XBRL data generators: the SONAR extension approach.

    PubMed

    Rodríguez-García, Miguel Ángel; Rodríguez-González, Alejandro; Colomo-Palacios, Ricardo; Valencia-García, Rafael; Gómez-Berbís, Juan Miguel; García-Sánchez, Francisco

    2014-01-01

    Precise, reliable and real-time financial information is critical for added-value financial services after the economic turmoil from which markets are still struggling to recover. Since the Web has become the most significant data source, intelligent crawlers based on Semantic Technologies have become trailblazers in the search of knowledge combining natural language processing and ontology engineering techniques. In this paper, we present the SONAR extension approach, which will leverage the potential of knowledge representation by extracting, managing, and turning scarce and disperse financial information into well-classified, structured, and widely used XBRL format-oriented knowledge, strongly supported by a proof-of-concept implementation and a thorough evaluation of the benefits of the approach.

  15. Undergraduates at Sea and in the Laboratory Conducting Habitat Mapping Using Multibeam and Sidescan Sonar

    NASA Astrophysics Data System (ADS)

    Sautter, L. R.; Harris, M. S.

    2008-12-01

    During the last five years, undergraduate students at the College of Charleston have had numerous opportunities to take part in the college's Transect Program and sail aboard research vessels on 2-5 day cruises to study the continental shelf. The program's purpose is to train students in oceanographic research while developing a long-term information geodatabase to characterize and monitor essential fish habitats, and to map seafloor geomorphology. During these cruises students take the lead to conduct a variety of research investigations which include hydrographic surveys of the seafloor using sidescan sonar, multibeam bathymetry, and video collected using a remotely operated vehicle and during SCUBA dives. Following the data collection cruises, students have enrolled in semester-long research courses to analyze data and document results through poster and oral presentations. More than 60 students have taken part in at least one of 6 programs. In the past two years, the NOAA Ship NANCY FOSTER has provided invaluable sea time to conduct multibeam surveys of the mid- and outer continental shelf off Charleston, so that the 22 participating Transect students have focused their work on seafloor mapping, and have become trained in state-of-the art CARIS multibeam and sidescan sonar processing software. Most of these students have presented their results at professional meetings, and manuscripts are currently in preparation. Students have had numerous post-program opportunities to conduct further research at sea and in the lab. They have collaborated with NOAA scientists and other investigators, conducting bathymetry data processing and analysis from other regions. Most recently, two program graduates worked with University of Washington investigators to map sites for the Ocean Observatory Initiative Regional Scale Nodes. Several students have been contracted or hired as hydrographic survey technicians, while others have gone to graduate school to continue their work

  16. Linear Scour Depressions or Bedforms? Using Interferometric Sonar to Investigate Nearshore Sediment Transport

    NASA Astrophysics Data System (ADS)

    Borrelli, M.; Giese, G. S.; Dingman, S. L.; Gontz, A. M.; Adams, M. B.; Norton, A. R.; Brown, T. L.

    2011-12-01

    A series of ambiguous features on the seafloor off the coast of Provincetown, Massachusetts USA has been identified in two bathymetric lidar surveys (2007, 2010) conducted by the US Army Corps of Engineers. Similar features in the area have been described as linear scour depressions by other investigators, but at deeper water depths. These features exhibit some of the characteristics of bedforms, they have migrated tens of meters and maintained similar 3 dimensional morphologies. However, what would be described as the slipface more closely resembles the updrift face of a linear scour depression. The features are in relatively shallow water (9 - 15 m), are 150 - 200 m long, have spacings of 100 - 150 m and are 5-6 m in height. Further investigations are being undertaken to better understand these features and nearshore sediment transport in the area. The features appear along a high energy, accreting coast with both strong wave-driven sediment flux and tidal currents. Mapping of the study area with an interferometric sonar system, which collects coincident swath bathymetry and acoustic backscatter imagery, is ongoing. Interferometric sonar increases bathymetric swath width to depth ratios, in comparison to multibeam systems, and expedites data collection by reducing costs, vessel-time and hazards associated with navigating shallow waters. In addition, sediment grab samples and a series of seismic reflection profiles will also be collected in the area to ground-truth acoustic imagery and provide a subsurface framework for the features, respectively. These datasets will allow investigators to better document bottom conditions, estimate flow velocities needed to create these features and improve our understanding of sediment transport processes and pathways in the area.

  17. Video Tutorials and Interactive Online Resources for Multibeam Sonar Software Training

    NASA Astrophysics Data System (ADS)

    Sautter, L. R.; Mode, J.; Duguid, P.

    2010-12-01

    For the past 5 years, undergraduate students at the College of Charleston (CofC) have had the opportunity to sail aboard the NOAA Ship Nancy Foster to collect multibeam sonar data for use in the Seafloor Mapping (SeaMap) Program. SeaMap is offered as an Academic Partnership with the CARIS software company, to train students to process and render multibeam bathymetric data using CARIS' HIPS and SIPS 7.0 software. During the semester-long program, students embellish their training by conducting independent research using sonar data provided by many NOAA and USGS collaborating scientists. Students create research posters to present at the annual CofC School of Science and Mathematics poster session and at professional meetings. To promote development of the SeaMap Program at CofC and other Academic Partner institutions, new approaches to training are being developed using online resources. This endeavor is part of the new CARIS Education Program and will incorporate bathymetric post processing using HIPS and SIPS 7.0. The HIPS Bathymetry Module consists of thirteen thematic units, each of which contains a suite of short online video tutorials focused on specific HIPS operations, with complementing interactive exercises and assessments. Students will convene for a weekend workshop for hands-on training with both a CARIS Instructor and the institution's professor. The workshop is followed by several laboratory sessions during which students practice their new skills using sample datasets. HIPS Bathymetry Module's online resources will be used throughout the program, and will be available afterwards, allowing students to revisit and supplement their learning. The Module will also be tested as a self-paced online course that will not necessitate a classroom presence. A demonstration of a thematic unit will be included in the presentation.

  18. High-Resolution Multibeam Sonar Survey and Interactive 3-D Exploration of the D-Day Wrecks off Normandy

    NASA Astrophysics Data System (ADS)

    Mayer, L. A.; Calder, B.; Schmidt, J. S.

    2003-12-01

    Historically, archaeological investigations use sidescan sonar and marine magnetometers as initial search tools. Targets are then examined through direct observation by divers, video, or photographs. Magnetometers can demonstrate the presence, absence, and relative susceptibility of ferrous objects but provide little indication of the nature of the target. Sidescan sonar can present a clear image of the overall nature of a target and its surrounding environment, but the sidescan image is often distorted and contains little information about the true 3-D shape of the object. Optical techniques allow precise identification of objects but suffer from very limited range, even in the best of situations. Modern high-resolution multibeam sonar offers an opportunity to cover a relatively large area from a safe distance above the target, while resolving the true three-dimensional (3-D) shape of the object with centimeter-level resolution. The combination of 3-D mapping and interactive 3-D visualization techniques provides a powerful new means to explore underwater artifacts. A clear demonstration of the applicability of high-resolution multibeam sonar to wreck and artifact investigations occurred when the Naval Historical Center (NHC), the Center for Coastal and Ocean Mapping (CCOM) at the University of New Hampshire, and Reson Inc., collaborated to explore the state of preservation and impact on the surrounding environment of a series of wrecks located off the coast of Normandy, France, adjacent to the American landing sectors The survey augmented previously collected magnetometer and high-resolution sidescan sonar data using a Reson 8125 high-resolution focused multibeam sonar with 240, 0.5° (at nadir) beams distributed over a 120° swath. The team investigated 21 areas in water depths ranging from about three -to 30 meters (m); some areas contained individual targets such as landing craft, barges, a destroyer, troop carrier, etc., while others contained multiple smaller

  19. Assessing Potential Sites for Undersea Warfare Training Ranges: The Effects of Active Sonars on Marine Mammals

    DTIC Science & Technology

    2008-10-28

    2) reconstruction of sound fields produced by the USS Shoup associated with the behavioral responses of killer whales observed in Haro Strait and...dolphins and beluga whales conducted by researchers at the SSC San Diego (Finneran et al., 2001, 2003, 2005; Finneran and Schlundt, 2004; Schlundt et al...uPa rms, and beluga whales did so at received levels of 180 to 196 dB and above. Test animals sometimes vocalized after an exposure to impulsive

  20. Classification of Elastic Objects by Active Sonar in the Vicinity of Shallow Sea Boundaries

    DTIC Science & Technology

    1992-04-01

    1969). 2. B. Baker and E. Copson, The Mathematical Theory of Huyqhen’s Principle, Oxford, Clarendon Press, England, ( 1953 ). 3. P. Morse and H. Feshbach...Metho2ds of Theoretical Physics, McGraw Hill, New York ( 1953 ), (See Chapter 13). 4. J. Jackson, Uagssical Electrodynamics, Wiley, New York, (1962...North Holland/Elsevier Publishers, (1989). 8. M. Danos and L. Maximon, "Multipole Matrix Elements of the Translation Operator," J. Mathem. Phys., 6, 766

  1. Least Squares Adaptive and Bayes Optimal Array Processors for the Active Sonar Problem

    DTIC Science & Technology

    1989-10-01

    False Alarm: Q10 = f po(z)dz (3.15) RI Miss: Q 1 = f pl(z)dz (3.16) RO Detection: Q11 = f P(z)dz (3.17) RI Null Decision: QDo f po(z)dz (3.18) RO where...least squares lattice filter structures for adaptive processing of complex acoustic data, The Pennsylvania State University, 1984. (Masters Thesis ) 54

  2. Environmentally associated signal-to-interference variability in low-frequency active sonar in Korea Strait

    NASA Astrophysics Data System (ADS)

    Cable, P. G.; Carey, W. M.

    2005-09-01

    An analysis has been conducted of spatial and temporal variability of target echo-to-interference measurements made during Area Characterization Test III (ACT III) in 1995 in the Korea Strait. The measurements were made over a 5-day period for five fixed bistatic geometries (spatial scale of order 200 square km) using explosive sources, bottom-mounted horizontal receiving hydrophone arrays, and passive reflector targets in 100-m-depth water under downward-refracting acoustic conditions. The bottom at the ACT III site was nearly flat, of sand-silt composition. Meteorological conditions were relatively calm over the conduction of the measurements, but the main proximate oceanographic feature, the South Korean Coastal Front, did result in a relatively varied and complex sound-speed environment. The signal-to-interference fluctuation statistics associated with a single ping was determined to give a standard deviation of order 1 dB, while the observed variability of signal-to-interference over the spatial and temporal scales of the measurements gave a standard deviation of about 2 dB. The observed variability of received signal-to-interference will be discussed in terms of physical causes and measurement error. [Work supported by ONR Code OA321.

  3. Experimental Comparison of High Duty Cycle and Pulsed Active Sonars in a Littoral Environment

    DTIC Science & Technology

    2014-09-30

    objectives of TREX. Please refer to Ref. [1] for an overview of the experimental goals. 3 target) but at the cost of higher technical risk. A...environmental knowledge to identify the best window of opportunity to execute military operations and provide tactical guidance for optimal deployment of...in the comments column implies HDC-PAS runs on the same track, the same direction ( inbound or outbound), and the same ER mode and gain settings

  4. A rail system for circular synthetic aperture sonar imaging and acoustic target strength measurements: design/operation/preliminary results.

    PubMed

    Kennedy, J L; Marston, T M; Lee, K; Lopes, J L; Lim, R

    2014-01-01

    A 22 m diameter circular rail, outfitted with a mobile sonar tower trolley, was designed, fabricated, instrumented with underwater acoustic transducers, and assembled on a 1.5 m thick sand layer at the bottom of a large freshwater pool to carry out sonar design and target scattering response studies. The mobile sonar tower translates along the rail via a drive motor controlled by customized LabVIEW software. The rail system is modular and assembly consists of separately deploying eight circular arc sections, measuring a nominal center radius of 11 m and 8.64 m arc length each, and having divers connect them together in the underwater environment. The system enables full scale measurements on targets of interest with 0.1° angular resolution over a complete 360° aperture, without disrupting target setup, and affording a level of control over target environment conditions and noise sources unachievable in standard field measurements. In recent use, the mobile cart carrying an instrumented sonar tower was translated along the rail in 720 equal position increments and acoustic backscatter data were acquired at each position. In addition, this system can accommodate both broadband monostatic and bistatic scattering measurements on targets of interest, allowing capture of target signature phenomena under diverse configurations to address current scientific and technical issues encountered in mine countermeasure and unexploded ordnance applications. In the work discussed here, the circular rail apparatus is used for acoustic backscatter testing, but this system also has the capacity to facilitate the acquisition of magnetic and optical sensor data from targets of interest. A brief description of the system design and operation will be presented along with preliminary processed results for data acquired from acoustic measurements conducted at the Naval Surface Warfare Center, Panama City Division Test Pond Facility. [Work Supported by the U.S. Office of Naval Research and

  5. 3S(expn 2): Behavioral Response Studies of Cetaceans to Navy Sonar Signals in Norwegian Waters

    DTIC Science & Technology

    2013-09-30

    killer whale sounds; 2.) Conduct a directed study on the effectiveness of ramp-up as a mitigation method with abundant and relatively easy-to-study...The earlier 3S research effort (see related programs) with killer , sperm, and long-finned pilot whales provides a dataset that enables comparative...in order to identify response thresholds. Playback of killer whale sounds is conducted to assess how responses to sonar might be shaped by

  6. 3S(expn 2): Behavioral Response Studies of Cetaceans to Navy Sonar Signals in Norwegian Waters

    DTIC Science & Technology

    2011-09-30

    behavioral reactions and the sound exposures required to elicit them of three species of whales : bottlenose whales , minke whales , and humpback whales to Low... humpback whales . OBJECTIVES In this research project, our objectives are to: 1.) Expand our comparative experimental dataset to include species...and relatively easy-to-study humpback whales , Megaptera novaeangliae; 3.) Record sufficient no-sonar baseline data of all target species to adequately

  7. Evaluation of Dual Frequency Identification Sonar (DIDSON) for Monitoring Pacific Lamprey Passage Behavior at Fishways of Bonneville Dam, 2011

    DTIC Science & Technology

    2012-01-01

    split into two categories: one for when minimum flow from both fish units exceeded 2 kcfs (reduced >= 2) and a second when flow from both units was...Technical Report 2012-5 IDAHO COOPERATIVE FISH AND WILDLIFE RESEARCH UNIT EVALUATION OF DUAL FREQUENCY IDENTIFICATION SONAR (DIDSON) FOR...Caudill1, P. N. Johnson2, W. T. Nagy3, and M. A. Jepson1 1Department of Fish and Wildlife Sciences and Idaho Cooperative Fish and Wildlife

  8. Function Analysis of TIAPS, Update of CANTASS Functionality and Human Factors Review of OMI Design for Sonar Combat Systems

    DTIC Science & Technology

    2001-03-01

    literature review should be read in the context of an earlier, more detailed review conducted for DREA (Matthews, Greenley and Webb, 1994), which contains a...Analysis Techniques for Man-Machine Systems Design. Report no. AC/243 (Panel 8)TR/7. 1999. Matthews, M. L., Greenley , M.P. and Webb, R. D. G. Human... Greenley , M.P., & Webb, R. D. G. (1994). Human Inteiface Modeling Issues for Sonar System Evaluation ( DREA CR/94/414): Prepared for Defence Research

  9. Detection and Classification of Buried UXO and Determination of Seafloor Parameters in Littoral Environments using Resonance Scattering Sonar

    DTIC Science & Technology

    2010-04-02

    Environmental Technology Technical Symposium and Workshop, Washington, D.C. Cobb, W. (2006), Acoustic identification of filler materials in unexploded...Underwater UXO Using Resonance Scattered Sonar, Partners in Environmental Technology Technical Symposium and Workshop, Washington, D.C., Dec. 1-3...Nelson, H., Yoder, T, Kraus, L. and Carin L., 2009, Broadband, Multi-Aspect Scattering from UXO, Partners in Environmental Technology Technical

  10. A prior-knowledge-based threshold segmentation method of forward-looking sonar images for underwater linear object detection

    NASA Astrophysics Data System (ADS)

    Liu, Lixin; Bian, Hongyu; Yagi, Shin-ichi; Yang, Xiaodong

    2016-07-01

    Raw sonar images may not be used for underwater detection or recognition directly because disturbances such as the grating-lobe and multi-path disturbance affect the gray-level distribution of sonar images and cause phantom echoes. To search for a more robust segmentation method with a reasonable computational cost, a prior-knowledge-based threshold segmentation method of underwater linear object detection is discussed. The possibility of guiding the segmentation threshold evolution of forward-looking sonar images using prior knowledge is verified by experiment. During the threshold evolution, the collinear relation of two lines that correspond to double peaks in the voting space of the edged image is used as the criterion of termination. The interaction is reflected in the sense that the Hough transform contributes to the basis of the collinear relation of lines, while the binary image generated from the current threshold provides the resource of the Hough transform. The experimental results show that the proposed method could maintain a good tradeoff between the segmentation quality and the computational time in comparison with conventional segmentation methods. The proposed method redounds to a further process for unsupervised underwater visual understanding.

  11. Sidescan-Sonar Imagery and Surficial Geologic Interpretations of the Sea Floor in Western Rhode Island Sound

    USGS Publications Warehouse

    McMullen, K.Y.; Poppe, L.J.; Haupt, T.A.; Crocker, J.M.

    2009-01-01

    The U.S. Geological Survey (USGS) and National Oceanic and Atmospheric Administration (NOAA) have been working together to interpret sea-floor geology along the northeastern coast of the United States. In 2004, the NOAA Ship RUDE completed survey H11322, a sidescan-sonar and bathymetric survey that covers about 60 square kilometers of the sea floor in western Rhode Island Sound. This report interprets sidescan-sonar and bathymetric data from NOAA survey H11322 to delineate sea-floor features and sedimentary environments in the study area. Paleozoic bedrock and Cretaceous Coastal Plain sediments in Rhode Island Sound underlie Pleistocene glacial drift that affects the distribution of surficial Holocene marine and transgressional sediments. The study area has three bathymetric highs separated by a channel system. Features and patterns in the sidescan-sonar imagery include low, moderate, and high backscatter; sand waves; scarps; erosional outliers; boulders; trawl marks; and dredge spoils. Four sedimentary environments in the study area, based on backscatter and bathymetric features, include those characterized by erosion or nondeposition, coarse-grained bedload transport, sorting and reworking, and deposition. Environments characterized by erosion or nondeposition and coarse-grained bedload transport are located in shallower areas and environments characterized by deposition are located in deeper areas; environments characterized by sorting and reworking processes are generally located at moderate depths.

  12. Hydrothermal flow at Main Endeavour Field imaged and measured with Cable Operated Vent Imaging Sonar

    NASA Astrophysics Data System (ADS)

    Rona, P. A.; Bemis, K. G.; Xu, G.; Jackson, D. R.; Jones, C. D.

    2011-12-01

    Initial acoustic monitoring of hydrothermal flow in the Main Endeavour Field (MEF) captures the spatial distribution of diffuse and focused discharge and shows potential for flux determinations. Our Cabled Observatory Vent Imaging Sonar (COVIS) was connected to the NEPTUNE Canada Endeavour Observatory in September 2010. Using a customized Reson 7125 multi-beam sonar, COVIS acquired a 29 day time series of black smoker plume and associated diffuse hydrothermal flow from Grotto, a 30 m diameter vent cluster in the MEF, Juan de Fuca Ridge. Detection of the spatial patterns of diffuse flow utilizes phase decorrelation of the acoustic signal (200kHz) by buoyancy-driven turbulence (acoustic scintillation) to produce a time series of maps. Substantial fluctuation in the detected diffuse flow area (0.1 - 18 m^2) was observed over the 29 days of observation, although position remained stable. Acoustic imaging of focused flow (400 kHz) utilizes high volume backscatter (attributed to particles and turbulent sound speed fluctuations) to image in 3D the initial tens of meters of rise of buoyant plumes. Spectral analysis of bending inclination of a strong plume from multiple fast smokers on the NW end of Grotto (north tower) indicates that the dominant modes correspond with the ambient mixed semi-diurnal tide (based on current meter data at a mooring 2.9 km to the north and on a tidal model), with at least one secondary mode attributable to sub-inertial flow related to inflow to the axial valley. A weaker plume from several slower smokers is present on the NE end of Grotto. On first analysis, the bending inclination of the weaker plume appears to be affected by the stronger plume. Quantification of flow velocity and volume flux of plumes begins with measuring the Doppler phase shift through plume cross-sections beginning at 5 m above source vents where discharge merges. The volume flux measurements enable calculation of entrainment coefficients, which prior work on the same

  13. Subduction of seamounts at the Java Trench: a view with long-range sidescan sonar

    NASA Astrophysics Data System (ADS)

    Masson, D. G.; Parson, L. M.; Milsom, J.; Nichols, G.; Sikumbang, N.; Dwiyanto, B.; Kallagher, H.

    1990-12-01

    We describe here a 1300 km by 45 km GLORIA long-range sidescan sonar swath along the eastern Java Trench. The swath images the trench axis, a narrow strip of oceanic crust to the south, and the toe of the accretionary wedge to the north, between 108° and 120° E. Sonar images of the ocean crust show a pattern of normal faults typical of the outer wall of trenches. These result from tension related to the bending of the oceanic lithosphere into the subduction zone. A number of sub-circular seamounts are also seen, some of which are currently being subducted. Isolated "ponds" of flat-lying sediments occur in the trench axis, although along much of its length the trench is devoid of such sediment accumulations. On the inner trench wall, the accretionary wedge is recognised by its distinctive "grainy" texture, with the grain aligned sub-parallel to the deformation front. Where subducting seamounts are colliding with the wedge, large crescentic areas of very high backscattering correlate with re-entrants in the deformation front and large indentations in the wedge. The high backscattering within these collision scars is interpreted to arise from outcropping strata and talus covered slopes, resulting from erosion of an inner trench wall shortened and oversteepened by collision with a seamount. All of the sediment ponds in the trench axis occur in close association with collision scars, strongly suggesting localised erosion of the accretionary wedge in the scar areas. However, the volume of the indentations appears to be an order of magnitude greater than the volume of eroded sediments deposited in the trench, indicating that erosion cannot be the primary mechanism by which indentations are created. Most of the "missing" material must be displaced landward by thrusting and folding ahead of the seamount. Our observations at the Java Trench are broadly comparable with those made at the Japan Trench by French and Japanese workers. However, some differences in the detail of

  14. Behavior of captive herring exposed to naval sonar transmissions (1.0-1.6 kHz) throughout a yearly cycle.

    PubMed

    Doksæter, Lise; Handegard, Nils Olav; Godø, Olav Rune; Kvadsheim, Petter H; Nordlund, Nina

    2012-02-01

    Atlantic herring, Clupea harengus, is a hearing specialist, and several studies have demonstrated strong responses to man-made noise, for example, from an approaching vessel. To avoid negative impacts from naval sonar operations, a set of studies of reaction patters of herring to low-frequency (1.0-1.5 kHz) naval sonar signals has been undertaken. This paper presents herring reactions to sonar signals and other stimuli when kept in captivity under detailed acoustic and video monitoring. Throughout the experiment, spanning three seasons of a year, the fish did not react significantly to sonar signals from a passing frigate, at received root-mean-square sound-pressure level (SPL) up to 168 dB re 1 μPa. In contrast, the fish did exhibit a significant diving reaction when exposed to other sounds, with a much lower SPL, e.g., from a two-stroke engine. This shows that the experimental setup is sensitive to herring reactions when occurring. The lack of herring reaction to sonar signals is consistent with earlier in situ behavioral studies. The complexity of the behavioral reactions in captivity underline the need for better understanding of the causal relationship between stimuli and reaction patterns of fish.

  15. Validation of a side-scan sonar method for quantifying walleye spawning habitat availability in the littoral zone of northern Wisconsin Lakes

    USGS Publications Warehouse

    Richter, Jacob T.; Sloss, Brian L.; Isermann, Daniel A.

    2016-01-01

    Previous research has generally ignored the potential effects of spawning habitat availability and quality on recruitment of Walleye Sander vitreus, largely because information on spawning habitat is lacking for many lakes. Furthermore, traditional transect-based methods used to describe habitat are time and labor intensive. Our objectives were to determine if side-scan sonar could be used to accurately classify Walleye spawning habitat in the nearshore littoral zone and provide lakewide estimates of spawning habitat availability similar to estimates obtained from a transect–quadrat-based method. Based on assessments completed on 16 northern Wisconsin lakes, interpretation of side-scan sonar images resulted in correct identification of substrate size-class for 93% (177 of 191) of selected locations and all incorrect classifications were within ± 1 class of the correct substrate size-class. Gravel, cobble, and rubble substrates were incorrectly identified from side-scan images in only two instances (1% misclassification), suggesting that side-scan sonar can be used to accurately identify preferred Walleye spawning substrates. Additionally, we detected no significant differences in estimates of lakewide littoral zone substrate compositions estimated using side-scan sonar and a traditional transect–quadrat-based method. Our results indicate that side-scan sonar offers a practical, accurate, and efficient technique for assessing substrate composition and quantifying potential Walleye spawning habitat in the nearshore littoral zone of north temperate lakes.

  16. Behavioral responses of herring (Clupea harengus) to 1-2 and 6-7 kHz sonar signals and killer whale feeding sounds.

    PubMed

    Doksaeter, Lise; Rune Godo, Olav; Olav Handegard, Nils; Kvadsheim, Petter H; Lam, Frans-Peter A; Donovan, Carl; Miller, Patrick J O

    2009-01-01

    Military antisubmarine sonars produce intense sounds within the hearing range of most clupeid fish. The behavioral reactions of overwintering herring (Clupea harengus) to sonar signals of two different frequency ranges (1-2 and 6-7 kHz), and to playback of killer whale feeding sounds, were tested in controlled exposure experiments in Vestfjorden, Norway, November 2006. The behavior of free ranging herring was monitored by two upward-looking echosounders. A vessel towing an operational naval sonar source approached and passed over one of them in a block design setup. No significant escape reactions, either vertically or horizontally, were detected in response to sonar transmissions. Killer whale feeding sounds induced vertical and horizontal movements of herring. The results indicate that neither transmission of 1-2 kHz nor 6-7 kHz have significant negative influence on herring on the received sound pressure level tested (127-197 and 139-209 dB(rms) re 1 microPa, respectively). Military sonars of such frequencies and source levels may thus be operated in areas of overwintering herring without substantially affecting herring behavior or herring fishery. The avoidance during playback of killer whale sounds demonstrates the nature of an avoidance reaction and the ability of the experimental design to reveal it.

  17. Modeling human echolocation of near-range targets with an audible sonar.

    PubMed

    Kuc, Roman; Kuc, Victor

    2016-02-01

    Blind humans echolocate nearby targets by emitting palatal clicks and perceiving echoes that the auditory system is not able to resolve temporally. The mechanism for perceiving near-range echoes is not known. This paper models the direct mouth-to-ear signal (MES) and the echo to show that the echo enhances the high-frequency components in the composite MES/echo signal with features that allow echolocation. The mouth emission beam narrows with increasing frequency and exhibits frequency-dependent transmission notches in the backward direction toward the ears as predicted by the piston-in-sphere model. The ears positioned behind the mouth detect a MES that contains predominantly the low frequencies contained in the emission. Hence the high-frequency components in the emission that are perceived by the ears are enhanced by the echoes. A pulse/echo audible sonar verifies this model by echolocating targets from 5 cm range, where the MES and echo overlap significantly, to 55 cm. The model predicts that unambiguous ranging occurs over a limited range and that there is an optimal range that produces the highest range resolution.

  18. Antifade sonar employs acoustic field diversity to recover signals from multipath fading

    SciTech Connect

    Lubman, D.

    1996-04-01

    Co-located pressure and particle motion (PM) hydrophones together with four-channel diversity combiners may be used to recover signals from multipath fading. Multipath fading is important in both shallow and deep water propagation and can be an important source of signal loss. The acoustic field diversity concept arises from the notion of conservation of signal energy and the observation that in rooms at least, the total acoustic energy density is the sum of potential energy (scalar field-sound pressure) and kinetic energy (vector field-sound PM) portions. One pressure hydrophone determines acoustic potential energy density at a point. In principle, three PM sensors (displacement, velocity, or acceleration) directed along orthogonal axes describe the kinetic energy density at a point. For a single plane wave, the time-averaged potential and kinetic field energies are identical everywhere. In multipath interference, however, potential and kinetic field energies at a point are partitioned unequally, depending mainly on relative signal phases. Thus, when pressure signals are in deep fade, abundant kinetic field signal energy may be available at that location. Performance benefits require a degree of uncorrelated fading between channels. The expectation of nearly uncorrelated fading is motivated from room theory. Performance benefits for sonar limited by independent Rayleigh fading are suggested by analogy to antifade radio. Average SNR can be improved by several decibels, holding time on target is multiplied manifold, and the bit error rate for data communication is reduced substantially. {copyright} {ital 1996 American Institute of Physics.}

  19. Circular synthetic aperture sonar imaging of simple objects illuminated by an evanescent wavefield.

    PubMed

    Plotnick, Daniel S; Marston, Timothy M; Marston, Philip L

    2016-10-01

    This paper is motivated by the case where an underwater object located within the sediment is illuminated by a grazing acoustic beam below the critical angle. The included experimental work uses a liquid-liquid interface and vertically inverted geometry as a stand-in for the water-sediment boundary. In the super-critical regime sound in the water column refracts into the sediment before scattering. However, for sub-critical illumination a rapidly decaying evanescent wavefield is generated in the sediment near the water-sediment interface. For compact objects located in the sediment near the interface this can result in strong backscattering signals suitable for acoustic image reconstruction using synthetic aperture sonar techniques. Certain properties of the evanescent wavefield such as the vertical phase-locking behavior, the rapid amplitude decay with distance from the interface, and the low-pass filter effect have understandable ramifications for the image formation process and for characteristics of the reconstructed image. In particular, circular imaging techniques require correct placement of the imaging plane to properly focus an object; however, for backscattering (monostatic) evanescent image formation the imaging plane may be placed at the interface and the target will remain in focus regardless of burial depth. A laboratory experiment using simple scatterers is presented.

  20. Auditory perception of objects by blind persons, using a bioacoustic high resolution air sonar.

    PubMed

    Kay, L

    2000-06-01

    A high-resolution octave band air sonar for spatial sensing and object imaging by blind persons is described. The system has wide-angle overlapping peripheral fields of view with a narrow central field superposed. It is noninvasively coupled to the auditory system for neural processing and spatial imaging. Blind persons learn to comprehend the auditory cortical multiple-object image that is created. The real-time synchronous relationship between hearing a change in the sensor sounds and the sensed motor actions causing the change seems to aid the learning process. Computer based testing of the sensor system is described so as to relate the physical system performance with the time-varying human auditory perception. This is so that the basic psychometric experiments studying the sensor bio-acoustic spatial resolution, resulting from the superposition of two wide-angle peripheral fields with one central narrow field, may be better understood. These tests confirm that the auditory ability of subjects to resolve close objects using the combined fields is significantly improved relative to using the peripheral fields alone. These measurements are supported by blind children learning to use the sensor system.

  1. Observations of the volume flux of a seafloor hydrothermal plume using an acoustic imaging sonar

    NASA Astrophysics Data System (ADS)

    Xu, G.; Jackson, D. R.; Bemis, K. G.; Rona, P. A.

    2013-07-01

    We present a 26 day time series (October 2010) of physical properties (volume flux, flow velocity, expansion rate) of a vigorous deep-sea hydrothermal plume measured using our Cabled Observatory Vent Imaging Sonar (COVIS), which is connected to the Northeast Pacific Time Series Underwater Experiment Canada Cabled Observatory at the Main Endeavour Field on the Juan de Fuca Ridge. COVIS quantitatively monitors the initial buoyant rise of the plume from ˜5 m to ˜15 m above the vents. The time series exhibits temporal variations of the plume vertical volume flux (1.93-5.09 m3/s ), centerline vertical velocity component (0.11-0.24 m/s ) and expansion rate (0.082-0.21 m/m ); these variations have major spectral peaks at semidiurnal (˜2 cycle/day) and inertial oscillation (˜1.5 cycle/day) frequencies. The plume expansion rate (average ˜0.14 m/m ) is inversely proportional to the plume centerline vertical velocity component (coefficient of determination R2˜0.5). This inverse proportionality, as well as the semidiurnal frequency, indicates interaction between the plume and ambient ocean currents consistent with an entrainment of ambient seawater that increases with the magnitude of ambient currents. The inertial oscillations observed in the time series provide evidence for the influence of surface storms on the dynamics of hydrothermal plumes.

  2. Analysis of signals under compositional noise with applications to SONAR data

    SciTech Connect

    Tucker, J. Derek; Wu, Wei; Srivastava, Anuj

    2013-07-09

    In this paper, we consider the problem of denoising and classification of SONAR signals observed under compositional noise, i.e., they have been warped randomly along the x-axis. The traditional techniques do not account for such noise and, consequently, cannot provide a robust classification of signals. We apply a recent framework that: 1) uses a distance-based objective function for data alignment and noise reduction; and 2) leads to warping-invariant distances between signals for robust clustering and classification. We use this framework to introduce two distances that can be used for signal classification: a) a y-distance, which is the distance between the aligned signals; and b) an x-distance that measures the amount of warping needed to align the signals. We focus on the task of clustering and classifying objects, using acoustic spectrum (acoustic color), which is complicated by the uncertainties in aspect angles at data collections. Small changes in the aspect angles corrupt signals in a way that amounts to compositional noise. As a result, we demonstrate the use of the developed metrics in classification of acoustic color data and highlight improvements in signal classification over current methods.

  3. Analysis of signals under compositional noise with applications to SONAR data

    DOE PAGES

    Tucker, J. Derek; Wu, Wei; Srivastava, Anuj

    2013-07-09

    In this paper, we consider the problem of denoising and classification of SONAR signals observed under compositional noise, i.e., they have been warped randomly along the x-axis. The traditional techniques do not account for such noise and, consequently, cannot provide a robust classification of signals. We apply a recent framework that: 1) uses a distance-based objective function for data alignment and noise reduction; and 2) leads to warping-invariant distances between signals for robust clustering and classification. We use this framework to introduce two distances that can be used for signal classification: a) a y-distance, which is the distance between themore » aligned signals; and b) an x-distance that measures the amount of warping needed to align the signals. We focus on the task of clustering and classifying objects, using acoustic spectrum (acoustic color), which is complicated by the uncertainties in aspect angles at data collections. Small changes in the aspect angles corrupt signals in a way that amounts to compositional noise. As a result, we demonstrate the use of the developed metrics in classification of acoustic color data and highlight improvements in signal classification over current methods.« less

  4. Imaging fall Chinook salmon redds in the Columbia River with a dual-frequency identification sonar

    USGS Publications Warehouse

    Tiffan, K.F.; Rondorf, D.W.; Skalicky, J.J.

    2004-01-01

    We tested the efficacy of a dual-frequency identification sonar (DIDSON) for imaging and enumeration of fall Chinook salmon Oncorhynchus tshawytscha redds in a spawning area below Bonneville Dam on the Columbia River. The DIDSON uses sound to form near-video-quality images and has the advantages of imaging in zero-visibility water and possessing a greater detection range and field of view than underwater video cameras. We suspected that the large size and distinct morphology of a fall Chinook salmon redd would facilitate acoustic imaging if the DIDSON was towed near the river bottom so as to cast an acoustic shadow from the tailspill over the redd pocket. We tested this idea by observing 22 different redds with an underwater video camera, spatially referencing their locations, and then navigating to them while imaging them with the DIDSON. All 22 redds were successfully imaged with the DIDSON. We subsequently conducted redd searches along transects to compare the number of redds imaged by the DIDSON with the number observed using an underwater video camera. We counted 117 redds with the DIDSON and 81 redds with the underwater video camera. Only one of the redds observed with the underwater video camera was not also documented by the DIDSON. In spite of the DIDSON's high cost, it may serve as a useful tool for enumerating fall Chinook salmon redds in conditions that are not conducive to underwater videography.

  5. Sonar-induced pressure fields in a post-mortem common dolphin.

    PubMed

    Foote, Kenneth G; Hastings, Mardi C; Ketten, Darlene R; Lin, Ying-Tsong; Reidenberg, Joy S; Rye, Kent

    2012-02-01

    Potential physical effects of sonar transmissions on marine mammals were investigated by measuring pressure fields induced in a 119-kg, 211-cm-long, young adult male common dolphin (Delphinus delphis) cadaver. The specimen was instrumented with tourmaline acoustic pressure gauges used as receiving sensors. Gauge implantation near critical tissues was guided by intraoperative, high-resolution, computerized tomography (CT) scanning. Instrumented structures included the melon, nares, ear, thoracic wall, lungs, epaxial muscle, and lower abdomen. The specimen was suspended from a frame equipped with a standard 50.8-mm-diameter spherical transducer used as the acoustic source and additional receiving sensors to monitor the transmitted and external, scattered field. Following immersion, the transducer transmitted pulsed sinusoidal signals at 5, 7, and 10 kHz. Quantitative internal pressure fields are reported for all cases except those in which the gauge failed or no received signal was detected. A full necropsy was performed immediately after the experiment to examine instrumented areas and all major organs. No lesions attributable to acoustic transmissions were found, consistent with the low source level and source-receiver distances.

  6. Computer simulations enhance experimental demonstrations in the underwater acoustics and sonar course

    NASA Astrophysics Data System (ADS)

    Korman, Murray S.

    2002-11-01

    Underwater acoustics and sonar (SP411) is a 3 hour course that is offered to midshipmen in their senior year. Typically, general science and oceanography majors, totaling 110 students/yr, enroll. Since this course is offered without a lab, the ''in class'' experience has been enhanced with the development (over many years) of our demo carts and computer workstations which surround the classroom. In a studio classroom atmosphere, students perform a variety of experiments in small groups. How can scientific visualizations best develop learning of complex interactions? Two examples are presented. PC-IMAT (personal curriculum interactive multisensor analysis training) simulations of multielement array steering support the theory and enhance the experiments that are performed in class such as the two-element array. Mathematica simulations involving the programming and animation of a point source in a rigid-rigid infinite parallel wave guide are used to stress the method of images, superposition, group and phase velocity and far-field modal pattern that is observed as a function of depth and source frequency. Later, students have fun using a ripple tank with an eye dropper to generate a point source between two adjustable parallel boundaries, and their understanding of ''underwater sound'' is greatly enhanced.

  7. Side-scan sonar mapping of lake trout spawning habitat in northern Lake Michigan

    USGS Publications Warehouse

    Edsall, Thomas A.; Poe, Thomas P.; Nester, Robert T.; Brown, Charles L.

    1989-01-01

    Native stocks of lake trout Salvelinus namaycush were virtually or completely extirpated from the lower four Great Lakes by the early 1960s. The failure of early attempts to reestablish self-sustaining populations of lake trout was attributed partly to the practice of stocking hatcheryreared juveniles at locations and over substrates that had not been used in the past for spawning by native fish. Subsequent attempts to improve the selection of stocking locations were impeded by the lack of reliable information on the distribution of substrates on historical spawning grounds. Here we demonstrate the potential of side-scan sonar to substantially expand the data base needed to pinpoint the location of substrates where lake trout eggs, fry, or juveniles could be stocked to maximize survival and help ensure that survivors returning to spawn would encounter suitable substrates. We also describe the substrates and bathymetry of large areas on historical lake trout spawning grounds in the Fox Island Lake Trout Sanctuary in northern Lake Michigan. These areas could be used to support a contemporary self-sustaining lake trout population in the sanctuary and perhaps also in adjacent waters.

  8. A necklace sonar with adjustable scope range for assisting the visually impaired.

    PubMed

    Villamizar, Luz H; Gualdron, Mauricio; Gonzalez, Fabio; Aceros, Juan; Rizzo-Sierra, Carlos V

    2013-01-01

    A sonar based device with tactile feedback was developed to improve the mobility and independence of visually impaired individuals. It features a transceiver/receiver, a potentiometer, a microcontroller, a rechargeable polymer lithium ion battery, and a Nokia Cell phone vibrator. All components are commercially available and housed in a custom acrylic package with 86 mm × 34 mm × 12 mm in dimension, and 120 grms in weight. Additionally, the device features an adjustable detection scheme for user customization of distance range, and a tactile feedback system that avoids interference with auditory sensory information. The device was tested for its navigational efficacy in an artificial indoor environment, and in a live outdoor setting. Ten subjects (9 males and 1 female), with a mean age of 35 years-old (range: 17 to 52) were presented with a series of navigational tasks resulting in considerable reduction of head, shoulder, chest, and arms collisions during their locomotion. We conclude that this device greatly improves the mobility and safety of visually impaired individuals.

  9. Estimating sturgeon abundance in the Carolinas using side-scan sonar

    USGS Publications Warehouse

    Flowers, H. Jared; Hightower, Joseph E.

    2015-01-01

    Sturgeons (Acipenseridae) are one of the most threatened taxa worldwide, including species in North Carolina and South Carolina. Populations of Atlantic Sturgeon Acipenser oxyrinchus in the Carolinas have been significantly reduced from historical levels by a combination of intense fishing and habitat loss. There is a need for estimates of current abundance, to describe status, and for estimates of historical abundance in order to provide realistic recovery goals. In this study we used N-mixture and distance models with data acquired from side-scan sonar surveys to estimate abundance of sturgeon in six major sturgeon rivers in North Carolina and South Carolina. Estimated abundances of sturgeon greater than 1 m TL in the Carolina distinct population segment (DPS) were 2,031 using the count model and 1,912 via the distance model. The Pee Dee River had the highest overall abundance of any river at 1,944 (count model) or 1,823 (distance model). These estimates do not account for sturgeon less than 1 m TL or occurring in riverine reaches not surveyed or in marine waters. Comparing the two models, the N-mixture model produced similar estimates using less data than the distance model with only a slight reduction of estimated precision.

  10. Sea ice thickness in the Weddell Sea, inferred from upward looking sonar measurements

    NASA Astrophysics Data System (ADS)

    Behrendt, Axel; Dierking, Wolfgang; Witte, Hannelore

    2014-05-01

    Sea ice has been routinely monitored by satellites since 1979. However, thickness measurements of sea ice are still very sparse, especially in the Southern Hemisphere. Satellite altimetry still provides relatively uncertain estimates of ice thickness. Today, the only tool for monitoring sea ice thickness over long time periods with highest accuracy (5-10 cm) are moored upward looking sonars (ULS). The instruments measure the subsurface portion (draft) of the ice, which can be converted into total ice thickness. We present a data set of ULS time series from 13 positions in the Atlantic sector of the Southern Ocean (Weddell Sea), which were made in different years between 1990 and 2010. Monthly mean sea ice draft shows high interannual variability and can reach more than 3 m in the dynamic coastal regions of the eastern and western Weddell Sea. The thinnest ice is found away from the coast in the eastern Weddell Sea and rarely exceeds 1 m in the monthly mean. In single years the ULS data allow for a clear discrimination between thermodynamic ice growth and dynamic ice growth due to rafting and ridging of the floes. We demonstrate that the thermodynamic ice thickness can reach its theoretical maximum value of 1 m in the central Weddell basin. Despite significant gaps, the presented data set provides an important validation tool for satellite algorithms and sea ice models.

  11. 50 CFR 216.270 - Specified activity and specified geographical region.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... frequency active sonar (HFAS) sources for U.S. Navy anti-submarine warfare (ASW), mine warfare (MIW) training, maintenance, or research, development, testing, and evaluation (RDT&E) in the amounts indicated... over the course of 5 years (an average of 494 hours per year) (iii) AN/BQQ-10 (submarine active...

  12. Characterization of swallowing sounds with the use of sonar Doppler in full-term and preterm newborns.

    PubMed

    Lagos, Hellen Nataly Correia; Santos, Rosane Sampaio; Abdulmassih, Edna Marcia da Silva; Gallinea, Liliane Friedrich; Langone, Mariangela

    2013-10-01

    Introduction Technological advances have provided a large variety of instruments to view the swallowing event, aiding in the evaluation, diagnosis, and monitoring of disturbances. These advances include electromyography of the surface, dynamic video fluoroscopy, and most recently sonar Doppler. Objective To characterize swallowing sounds in typical children through the use of sonar Doppler. Method Thirty newborns participated in this prospective study. All newborns received breast milk through either their mother's breasts or bottles during data collection. The newborns were placed in either right lateral or left lateral positions when given breast milk through their mother's breasts and in a sitting position when given a bottle. There were five variables measured: initial frequency of sound wave (FoI), frequency of the first peak of the sound wave (FoP1), frequency of the second peak of the sound wave (FoP2), initial intensity and final sound wave (II and IF), and swallowing length (T), the time elapsed from the beginning until the end of the analyzed acoustic signal measured by the audio signal, in seconds. Results The values obtained in the initial frequency of the babies had a mean of 850 Hz. In terms of frequency of first peak, only three presented with a subtle peak, which was due to the elevated larynx position. Conclusion The use of sonar Doppler as a complementary exam for clinical evaluations is of upmost importance because it is nonintrusive and painless, and it is not necessary to place patients in a special room or expose them to radiation.

  13. Digital image processing techniques for enhancement and classification of SeaMARC II side scan sonar imagery

    NASA Astrophysics Data System (ADS)

    Reed, Thomas Beckett, IV; Hussong, Donald

    1989-06-01

    The recent growth in the production rate of digital side scan sonar images, coupled with the rapid expansion of systematic seafloor exploration programs, has created a need for fast and quantitative means of processing seafloor imagery. Computer-aided analytical techniques fill this need. A number of numerical techniques used to enhance and classify imagery produced by SeaMARC II, a long-range combination side scan sonar, and bathymetric seafloor mapping system are documented. Three categories of techniques are presented: (1) preprocessing corrections (radiometric and geometric), (2) feature extraction, and (3) image segmentation and classification. An introduction to the concept of "feature vectors" is provided, along with an explanation of the method of evaluation of a texture feature vector based upon gray-level co-occurrence matrices (GLCM). An alternative to the a priori texel (texture element) subdivision of images is presented in the form of region growing and texture analysis (REGATA). This routine provides a texture map of spatial resolution superior to that obtainable with arbitrarily assigned texel boundaries and minimizes the possibility of mixed texture signals due to the combination of two or more textures in an arbitrarily assigned texel. Computer classification of these textural features extracted via the GLCM technique results in transformation of images into maps of image texture. These maps may either be interpreted in terms of the theoretical relationships shown between texture signatures and wavelength or converted to geologic maps by correlation of texture signatures with ground truth data. These techniques are applied to SeaMARC II side scan sonar imagery from a variety of geologic environments, including lithified and nonlithified sedimentary formations, volcanic and sedimentary debris flows, and crystalline basaltic outcrops. Application of the above processing steps provided not only superior images for both subjective and quantitative

  14. Using Digital Acoustic Recording Tags to Detect Marine Mammals on Navy Ranges and Study their Responses to Naval Sonar

    DTIC Science & Technology

    2011-02-01

    7 Materials and Methods………………………………….. 12 Results and Discussion………………………………….. 20 Conclusions and Implications for Future Research/Implementation...beaked whales exposed to playback of sound, and has developed and validated a method to associate acoustic exposure with a safe response. The... safe exposure levels for beaked and other whales when they are exposed to military sonars. The DTAG was designed not only to record sounds produced by

  15. Sidescan-Sonar Imagery and Surficial Geologic Interpretations of the Sea Floor in Central Rhode Island Sound

    USGS Publications Warehouse

    McMullen, K.Y.; Poppe, L.J.; Denny, J.F.; Haupt, T.A.; Crocker, J.M.

    2008-01-01

    The U.S. Geological Survey (USGS) has been working with the National Oceanic and Atmospheric Administration (NOAA) to interpret the surficial geology of areas along the northeastern coast of the United States. During 2004, the NOAA Ship RUDE conducted Hydrographic Survey H11321 in Rhode Island Sound. This sidescan-sonar and bathymetry survey covers an area of 93 km? located 12 km southeast of Brenton Point, RI in water depths of 28-39 m (fig. 1). The purpose of this report is to delineate sea floor features and sedimentary environments of this area in central Rhode Island Sound using sidescan-sonar and bathymetric data from NOAA Survey H11321 and seismic-reflection data from a previous USGS field study (Needell and others, 1983a). This is important for the study of benthic habitats and provides a framework for future research. Prior work in this area includes the mapping of surface sediments and surficial geology. McMaster (1960) collected sediment samples from Rhode Island Sound and Narragansett Bay and mapped our study area as having a sandy sea floor. In addition, one sample of sand from the National Ocean Service (NOS) Hydrographic Database came from a location in the northeast part of our study area in 1939 (fig. 2; Poppe and others, 2003). McMaster and others (1968) used seismic-reflection profiles to map the locations of a cuesta of Cretaceous sediments crossing Rhode Island Sound and post-Cretaceous drainage channels. Knebel and others (1982) identified sedimentary environments in Rhode Island Sound using sidescan sonographs. Needell and others (1983b) studied the Quaternary geology and mapped the structure, sedimentary environments, and geologic hazards in Rhode Island Sound using sidescan-sonar and seismic-reflection data. Sidescan-sonar and bathymetric data from NOAA Survey H11320, which overlaps the far eastern edge of our study area, was interpreted to consist of basins surrounded by a moraine and bathymetric highs composed of till with areas of rocks

  16. Morphology of upper laurentian fan using GLORIA long-range side-scan sonar

    SciTech Connect

    Masson, D.G.; Field, M.E.; Gardner, J.V.; Parson, L.M.

    1985-06-01

    A long-range side-scan sonar (GLORIA) survey of the upper Laurentian Fan shows, for the first time, the regional geomorphology of this large and complex sedimentary body. The channels of the upper continental slope coalesce on the upper fan to form four major fan valleys. The largest of these, Eastern Valley, is U-shaped in cross section and up to 25 km (15 mi) wide with a large levee on the western flank that reaches a maximum height of more than 1 km (3,300 ft) above the valley floor. The remaining valleys, Western, Central, and Grand Banks, are typically more V-shaped in cross section and are up to 5 km (3 mi) wide. Extensive gullying is observed on the walls of all the channels. Sonographs of the floor of Eastern Valley show a strong, linear fabric elongated parallel with the valley walls that appears to be related to mesoscale relief on the valley floor. At water depths between 3,500 and 4,100 m (11,550 and 13,530 ft), two major fan valleys are created by the merging of the four major valleys of the upper fan. Both fan valleys are associated with large, asymmetric levee complexes that reach heights of more than 500 m (1,650 ft) above the valley floors. The GLORIA data show evidence for several amphitheaterlike slump scars in the region of the 1929 earthquake epicenter. However, the authors see no evidence for movement of large coherent sediment blocks as postulated by earlier workers. They suggest that the turbidity currents that occurred after the 1929 earthquake may have formed by the coalescence of many small slumps rather than from a single large slump.

  17. Atwater Valley Deep-Towed Sidescan Sonar Imagery and Bathymetric Survey

    SciTech Connect

    Joan M. Gardner; Mike Czarnecki; Rick Hagen; Clyde Nishimura; Warren Wood; Chad Vaughn; Jody Bruton; Pat Hart; Emil Bergeron; Deborah Hutchinson

    2005-11-22

    The purpose of this project was to conduct detailed surface mapping of one of the areas drilled by the Joint Industry Project with ChevronTexaco to understand gas hydrates in the Gulf of Mexico. The gently sloping, mostly flat floor of the Mississippi Canyon is interrupted by mounds and depressions that presumably reflect the complex geology and geohydrology related to turbidite deposition and pervasive salt tectonism. The seafloor mounds we mapped in this study occur in approximately 1300 water depth along the floor of the Mississippi Canyon in lease block areas Atwater Valley 13 and 14. High resolution sidescan sonar (100 kHz and 500 kHz) backscatter imagery, and chirp sub-bottom profiler data were collected using the DT1 deep-towed oceanographic mapping instrument, concentrating on the region directly adjacent to and surrounding two mounds identified as, mounds D and F, and in the region directly adjacent to and surrounding the mounds. The backscatter data have been mosaiced and normalized to provide information on the shape and extent of the mounds, the possible lateral extent of fauna, such as mussel and clam fields on the mounds, possible seep related flows and the occurrence of carbonate material. The extent of a mudflow can be mapped on the southeastern side of mound F. The backscatter data show extremely high-resolution detail about the shape, relief, and morphology of the mounds. This information, coupled with porewater chemistry , DTAGS and heatflow data form a coherent picture of possible mechanics for fluid venting and flora/fauna of the seeps in this region.

  18. Arctic sea ice thickness characteristics in winter 2004 and 2007 from submarine sonar transects

    NASA Astrophysics Data System (ADS)

    Wadhams, Peter; Hughes, Nick; Rodrigues, JoãO.

    2011-08-01

    A transect of the Arctic Ocean by the British submarine Tireless in March 2007 enabled the thickness characteristics of the ice cover to be measured during the winter immediately preceding the exceptional retreat of summer 2007. In this paper we report on mean and modal drafts, probability density functions of draft, and the frequency and depth distribution of pressure ridges, and we compare results with those from an earlier submarine cruise in winter 2004 which covered part of the same area. In the region from north of Fram Strait to Ellesmere Island (about 85°N, 0-70°W) we find no change in mean drafts between 2004 and 2007 though there is a change in ice composition, with more ridging in 2007 but a lesser modal draft. This agrees with the observations of younger ice being driven toward Fram Strait in 2007. The region north of Ellesmere Island continues to be a "redoubt" containing more thick deformed multiyear ice than any other part of the transect. In the west the submarine profiled extensively under the SEDNA ice camp at 73°N 145°W. This is in the same location as the 1976 AIDJEX ice camp and a sonar survey done by a U.S. submarine in April 1976. We found that a large decrease in mean draft had occurred (32%) over 31 years and that in 2007 the SEDNA region contained the thinnest ice of any part of the Arctic surveyed by the submarine; this was a region from which the ice completely retreated during the subsequent summer of 2007.

  19. Morphology of central California continental margin, revealed by long-range side-scan sonar (GLORIA)

    SciTech Connect

    Gardner, J.V.; McCulloch, D.S.; Eittreim, S.L.; Masson, D.G.

    1985-02-01

    Leg 2 of the 4-leg USGS EEZ-SCAN 84 program used GLORIA long-range side-scan sonar to survey the region from Pt. Conception to just south of Pt. Arena, from the shelf break to the 200-nmi coverage. The overlapping digital sonographs were slant-range and anamorphically corrected, and a photomosaic of the sonographs was constructed at a scale of 1:375,000 (1 in. = 11.1 km). The underlying bed rock appears to be an important control in shaping the morphology of this margin. Several faults have sea-floor expression and lie subparallel to the margin. The density of canyons and gullies on the slope varies from south to north, probably because of variations in the characteristics of the bed rock. The slope west of San Francisco is the most dissected segment of the central California slope. Monterey Fan is covered by large-scale bed forms (5-15 m amplitude and 1.5-2.0 km wavelength) over much of its surface. Monterey channel crosses southwestward across the fan, but abruptly turns south along a 40-km long surface fault that coincides with a well-mapped meander loop. The channel loops to the north then turns southward crossing the entire Monterey Fan, at its distal reaches, changes to a broad, braided pattern. Major slumps on the margin have long (> 30 km) scarps, some have slump folds, and one has a debris-flow deposit that can be acoustically traced for more than 75 km. Seventeen new seamounts were mapped. Taney Seamounts are large, rimmed, calderas with diameters of about 15 km each; these appear to be very large explosive or summit-collapse features.

  20. Measuring nighttime spawning behavior of chum salmon using a dual-frequency identification sonar (DIDSON)

    USGS Publications Warehouse

    Tiffan, K.F.; Rondorf, D.W.

    2005-01-01

    The striking body coloration and morphology that Pacific salmon display during spawning coupled with elaborate courtship behaviors suggest that visual cues are important during their reproductive period. To date, virtually all existing information on chum salmon (Oncorhynchus keta) spawning behavior has been derived from studies conducted during the daytime, and has contributed to the assumption that salmon do not spawn at night. We tested this assumption using a new technology - a dual-frequency identification sonar (DIDSON) - to describe and measure nighttime spawning behavior of wild chum salmon in the Columbia River. The DIDSON produces detailed, video-like images using sound, which enabled us to collect behavioral information at night in complete darkness. The display of DIDSON images enabled fish movements and behaviors to be spatially quantified. We collected continuous observational data on 14 pairs of chum salmon in a natural spawning channel during the daytime and nighttime. Spawners of both genders were observed chasing intruders during nighttime and daytime as nests were constructed. Regardless of diel period, females were engaged in digging to both construct nests and cover eggs, and courting males exhibited the pre-spawning behavior of tail crossing. We observed a total of 13 spawning events, of which nine occurred at night and four occurred during the day. The behaviors we observed at night suggest the assumption that chum salmon do not spawn at night is false. Once chum salmon begin nest construction, visual cues are apparently not required for courtship, nest defense, and spawning. We speculate that non-visual cues (e.g. tactile and auditory) enable chum salmon to carry out most spawning behaviors at night. Our findings have implications for how nighttime flows from hydroelectric dams on the Columbia River are managed for power production and protection of imperiled salmon stocks.

  1. 2.5-kHz magnetostrictive Tonpilz sonar transducer design

    NASA Astrophysics Data System (ADS)

    Butler, Stephen C.

    2002-07-01

    Naval Undersea Warfare Center has fabricated and tested a 2.5 kHz magnetostrictive sonar transducer to validate various modeling techniques. The transducer selected is a longitudinal vibrator Tonpilz type consisting of Terfenol-D driver, tail mass, radiating head mass, and stress rod bolt with 21 MPa (3000 psi) prestress. The Terfenol-D drive rod is interlaced with three samarium cobalt magnets, one in the center and one on either end magnetically biasing the Terfenol to 60 kA/m (750 Oe). Both the Terfenol-D rods and magnets were laminated to reduce eddy currents. The magnetic circuit is comprised of pole piece discs on each end of the Terfenol-D magnet assembly and an external magnetic cylinder (return path) made of a high-permeability, high-resistivity, high-saturation powdered metal 'T2'. The transducer has a 25 cm (9.8in) diameter radiating face (piston), is 28 cm (11 in.) long, and weighs 15 kg (32 lb.) without the housing. It is 41 cm (16 in.) long and 25 kg (56 lb.) with the underwater housing. The measured results are compared to a finite element model using 'ATILA' and distributed plane wave element equivalent circuit model. The coupling coefficient, permeability and mechanical loss effects for different prestress loads were measured on a resonant Terfenol 'dumbbell' device. The in-water measured results indicate a mechanical Q of 2.5, an effective coupling coefficient of 0.36, an electro-acoustic efficiency of 60 percent, beam pattern directivity index of 6 dB, a maximum Source Level of 214.6 dB re 1uPa/m at 15 Amps AC drive and bandwidth of 2 kHz to 5.4 kHz +/- 1.5 dB.

  2. Archive of Side Scan Sonar and Swath Bathymetry Data collected during USGS Cruise 10CCT02 Offshore of Petit Bois Island Including Petit Bois Pass, Gulf Islands National Seashore, Mississippi, March 2010

    USGS Publications Warehouse

    Pfeiffer, William R.; Flocks, James G.; DeWitt, Nancy T.; Forde, Arnell S.; Kelso, Kyle; Thompson, Phillip R.; Wiese, Dana S.

    2011-01-01

    In March of 2010, the U.S. Geological Survey (USGS) conducted geophysical surveys offshore of Petit Bois Island, Mississippi, and Dauphin Island, Alabama (fig. 1). These efforts were part of the USGS Gulf of Mexico Science Coordination partnership with the U.S. Army Corps of Engineers (USACE) to assist the Mississippi Coastal Improvements Program (MsCIP) and the Northern Gulf of Mexico (NGOM) Ecosystem Change and Hazards Susceptibility Project by mapping the shallow geologic stratigraphic framework of the Mississippi Barrier Island Complex. These geophysical surveys will provide the data necessary for scientists to define, interpret, and provide baseline bathymetry and seafloor habitat for this area and to aid scientists in predicting future geomorphological changes of the islands with respect to climate change, storm impact, and sea-level rise. Furthermore, these data will provide information for barrier island restoration, particularly in Camille Cut, and protection for the historical Fort Massachusetts on Ship Island, Mississippi. For more information please refer to http://ngom.usgs.gov/gomsc/mscip/index.html. This report serves as an archive of the processed swath bathymetry and side scan sonar data (SSS). Data products herein include gridded and interpolated surfaces, seabed backscatter images, and ASCII x,y,z data products for both swath bathymetry and side scan sonar imagery. Additional files include trackline maps, navigation files, GIS files, Field Activity Collection System (FACS) logs, and formal FGDC metadata. Scanned images of the handwritten and digital FACS logs are also provided as PDF files. Refer to the Acronyms page for expansion of acronyms and abbreviations used in this report.

  3. The evaluation of swallowing in patients with spinocerebellar ataxia and oropharyngeal dysphagia: A comparison study of videofluoroscopic and sonar doppler

    PubMed Central

    Abdulmassih, Edna Márcia da Silva; Teive, Hélio Afonso Ghizoni; Santos, Rosane Sampaio

    2013-01-01

    Sumarry Introduction: Spinocerebellar ataxia (SCA) is a degenerative disease that can cause loss of coordination of voluntary muscle movement such as that required for swallowing. Aims: The purposes of this cross-sectional and comparative case study were: (1) to assess the severity of dysphagia through a videofluoroscopic swallow study, and (2) to compare differences in frequency, intensity, and duration of sound waves produced during swallowing in normal and SCA patients by using sonar Doppler. Method: During swallow evaluation using videofluoroscopy, a sonar Doppler transducer was placed on the right side of the neck, at the lateral edge of the trachea, just below the cricoid cartilage to capture the sounds of swallowing in 30 SCA patients and 30 controls. Result: The prevalence in the dynamic evaluation of swallowing videofluoroscopy was by changes in the oral phase of swallowing. The analysis of variance of the averages found in each variable - frequency, intensity and duration of swallowing - shows there was a significant correlation when compared to the healthy individual curve. Conclusion: The study demonstrates the prevalence of oral dysphagia observed in dynamic videofluoroscopic swallow evaluation. In patients with SCA, the mean initial frequency (IF), initial intensity (II), and final intensity (FI) were higher and the time (T) and peak frequency (PF) were lower, demonstrating a pattern of cricopharyngeal opening very close to that found in normal populations. PMID:26038680

  4. Combining split-beam and dual-frequency identification sonars to estimate abundance of anadromous fishes in the Roanoke River, North Carolina

    USGS Publications Warehouse

    Hughes, Jacob B.; Hightower, Joseph E.

    2015-01-01

    Riverine hydroacoustic techniques are an effective method for evaluating abundance of upstream migrating anadromous fishes. To use these methods in the Roanoke River, North Carolina, at a wide site with uneven bottom topography, we used a combination of split-beam sonar and dual-frequency identification sonar (DIDSON) deployments. We aimed a split-beam sonar horizontally to monitor midchannel and near-bottom zones continuously over the 3-month spring monitoring periods in 2010 and 2011. The DIDSON was rotated between seven cross-channel locations (using a vertical aim) and nearshore regions (using horizontal aims). Vertical deployment addressed blind spots in split-beam coverage along the bottom and provided reliable information about the cross-channel and vertical distributions of upstream migrants. Using a Bayesian framework, we modeled sonar counts within four cross-channel strata and apportioned counts by species using species proportions from boat electrofishing and gill netting. Modeled estimates (95% credible intervals [CIs]) of total upstream migrants in 2010 and 2011 were 2.5 million (95% CI, 2.4–2.6 million) and 3.6 million (95% CI, 3.4–3.9 million), respectively. Results indicated that upstream migrants are extremely shore- and bottom-oriented, suggesting nearshore DIDSON monitoring improved the accuracy and precision of our estimates. This monitoring protocol and model may be widely applicable to river systems regardless of their cross-sectional width or profile.

  5. Cost-effective mapping of benthic habitats in inland reservoirs through split-beam sonar, indicator kriging, and historical geologic data.

    PubMed

    Venteris, Erik R; May, Cassandra J

    2014-01-01

    Because bottom substrate composition is an important control on the temporal and spatial location of the aquatic community, accurate maps of benthic habitats of inland lakes and reservoirs provide valuable information to managers, recreational users, and scientists. Therefore, we collected vertical, split-beam sonar data (roughness [E1], hardness [E2], and bathymetry) and sediment samples to make such maps. Statistical calibration between sonar parameters and sediment classes was problematic because the E1:E2 ratios for soft (muck and clay) sediments overlapped a lower and narrower range for hard (gravel) substrates. Thus, we used indicator kriging (IK) to map the probability that unsampled locations did not contain coarse sediments. To overcome the calibration issue we tested proxies for the natural processes and anthropogenic history of the reservoir as potential predictive variables. Of these, a geologic map proved to be the most useful. The central alluvial valley and mudflats contained mainly muck and organic-rich clays. The surrounding glacial till and shale bedrock uplands contained mainly poorly sorted gravels. Anomalies in the sonar data suggested that the organic-rich sediments also contained trapped gases, presenting additional interpretive issues for the mapping. We extended the capability of inexpensive split-beam sonar units through the incorporation of historic geologic maps and other records as well as validation with dredge samples. Through the integration of information from multiple data sets, were able to objectively identify bottom substrate and provide reservoir users with an accurate map of available benthic habitat.

  6. Cost-Effective Mapping of Benthic Habitats in Inland Reservoirs through Split-Beam Sonar, Indicator Kriging, and Historical Geologic Data

    PubMed Central

    Venteris, Erik R.; May, Cassandra J.

    2014-01-01

    Because bottom substrate composition is an important control on the temporal and spatial location of the aquatic community, accurate maps of benthic habitats of inland lakes and reservoirs provide valuable information to managers, recreational users, and scientists. Therefore, we collected vertical, split-beam sonar data (roughness [E1], hardness [E2], and bathymetry) and sediment samples to make such maps. Statistical calibration between sonar parameters and sediment classes was problematic because the E1:E2 ratios for soft (muck and clay) sediments overlapped a lower and narrower range for hard (gravel) substrates. Thus, we used indicator kriging (IK) to map the probability that unsampled locations did not contain coarse sediments. To overcome the calibration issue we tested proxies for the natural processes and anthropogenic history of the reservoir as potential predictive variables. Of these, a geologic map proved to be the most useful. The central alluvial valley and mudflats contained mainly muck and organic-rich clays. The surrounding glacial till and shale bedrock uplands contained mainly poorly sorted gravels. Anomalies in the sonar data suggested that the organic-rich sediments also contained trapped gases, presenting additional interpretive issues for the mapping. We extended the capability of inexpensive split-beam sonar units through the incorporation of historic geologic maps and other records as well as validation with dredge samples. Through the integration of information from multiple data sets, were able to objectively identify bottom substrate and provide reservoir users with an accurate map of available benthic habitat. PMID:24759834

  7. Cost-Effective Mapping of Benthic Habitats in Inland Reservoirs through Split-Beam Sonar, Indicator Kriging, and Historical Geologic Data

    SciTech Connect

    Venteris, Erik R.; May, Cassandra

    2014-04-23

    Because bottom substrate composition is an important control on the temporal and spatial location of the aquatic community, accurate maps of benthic habitats of inland lakes and reservoirs provide valuable information to managers, recreational users, and scientists. Therefore, we collected vertical, split-beam sonar data (roughness [E1], hardness [E2], and bathymetry) and sediment samples to make such maps. Statistical calibration between sonar parameters and sediment classes was problematic because the E1:E2 ratios for soft (muck and clay) sediments overlapped a lower and narrower range for hard (gravel) substrates. Thus, we used indicator kriging (IK) to map the probability that unsampled locations did not contain coarse sediments. To overcome the calibration issue we tested proxies for the natural processes and anthropogenic history of the reservoir as potential predictive variables. Of these, a geologic map proved to be the most useful. The central alluvial valley and mudflats contained mainly muck and organic-rich clays. The surrounding glacial till and shale bedrock uplands contained mainly poorly sorted gravels. Anomalies in the sonar data suggested that the organic-rich sediments also contained trapped gases, presenting additional interpretive issues for the mapping. We extended the capability of inexpensive split-beam sonar units through the incorporation of historic geologic maps and other records as well as validation with dredge samples. Through the integration of information from multiple data sets, were able to objectively identify bottom substrate and provide reservoir users with an accurate map of available benthic habitat.

  8. 78 FR 35851 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-14

    ... Sources The acoustic sources of primary concern are the airguns that will be deployed from the seismic... on Marine Mammals Operating active acoustic sources such as airgun arrays, navigational sonars, and... desirable acoustic environment; and Cease feeding or social interaction. For example, at the Guerreo...

  9. Compiling Multibeam Sonar data for the U.S. Pacific West Coast Extended Continental Shelf Project

    NASA Astrophysics Data System (ADS)

    Lim, E.; Gardner, J. V.; Henderson, J. F.

    2011-12-01

    meters. The individual surveys were compiled to form a comprehensive grid of the entire region, which covers an area of approximately 1,110,000 square kilometers. Applications such as MB-System, Geospatial Data Abstraction Library (GDAL), Generic Mapping Tools (GMT), and Fledermaus were used to grid, compile, and visualize the data. This study focuses on the gridding methods, compilation, and pitfalls of creating a large-scale multibeam sonar grid for use on a single region of the U.S ECS project.

  10. In vivo monitoring of cellular energy metabolism using SoNar, a highly responsive sensor for NAD(+)/NADH redox state.

    PubMed

    Zhao, Yuzheng; Wang, Aoxue; Zou, Yejun; Su, Ni; Loscalzo, Joseph; Yang, Yi

    2016-08-01

    NADH and its oxidized form NAD(+) have a central role in energy metabolism, and their concentrations are often considered to be among the most important readouts of metabolic state. Here, we present a detailed protocol to image and monitor NAD(+)/NADH redox state in living cells and in vivo using a highly responsive, genetically encoded fluorescent sensor known as SoNar (sensor of NAD(H) redox). The chimeric SoNar protein was initially developed by inserting circularly permuted yellow fluorescent protein (cpYFP) into the NADH-binding domain of Rex protein from Thermus aquaticus (T-Rex). It functions by binding to either NAD(+) or NADH, thus inducing protein conformational changes that affect its fluorescent properties. We first describe steps for how to establish SoNar-expressing cells, and then discuss how to use the system to quantify the intracellular redox state. This approach is sensitive, accurate, simple and able to report subtle perturbations of various pathways of energy metabolism in real time. We also detail the application of SoNar to high-throughput chemical screening of candidate compounds targeting cell metabolism in a microplate-reader-based assay, along with in vivo fluorescence imaging of tumor xenografts expressing SoNar in mice. Typically, the approximate time frame for fluorescence imaging of SoNar is 30 min for living cells and 60 min for living mice. For high-throughput chemical screening in a 384-well-plate assay, the whole procedure generally takes no longer than 60 min to assess the effects of 380 compounds on cell metabolism.

  11. Seafloor image survey of Juk-byeon port in Uljin, South Korea, using side scan sonar with a fixed long frame

    NASA Astrophysics Data System (ADS)

    Kim, W. H.; Park, C.; Lee, M.; Park, H. Y.; Kim, C.

    2015-12-01

    A side scan sonar launches ultrasonic wave from both sides of the transducer. And it restores the image by receiving signals. It measures the strength of how "loud" the return echo is, and paints a picture. Hard areas of the sea floor like rocks reflect more return signal than softer areas like sand. We conducted seafloor image survey from 4, Mar. 2013 using R/V Jangmok2 (35ton), side scan sonar 4125 (Edge Tech corporation). The side scan sonar system (4125) is a dual frequency system of 400/900kHz. Seafloor image survey is commonly used to tow the sensor in the rear side of vessel. However, we fixed the tow-fish on right side of the vessel in the seawater with a long frame. The mounted side scan sonar survey was useful in shallow water like the port having many obstacles. And we conducted submarine topography using multi-beam echo sounder EM3001 (Kongs-berg corporation). Multi-beam echo sounder is a device for observing and recording the submarine topography using sound. We mounted the EM3001 on right side of the vessel. Multi-beam echo sounder transducer commonly to mount at right angles to the surface of water. However, we tilted 20-degrees of transducer for long range with 85-degrees measurement on the right side of the vessel. We were equipped with a motion sensor, DGPS(Differential Global Positioning System), and SV(Sound velocity) sensor for the vessel's motion compensation, vessel's position, and the velocity of sound of seawater. The surveys showed the sediment, waste materials, and a lot of discarded tires accumulated in the port. The maximum depth was 12m in the port. Such multi-beam echo sounder survey and side scan sonar survey will facilitate the management and the improvement of environment of port.

  12. Side-Scan Sonar Observations off Santa Rosa Island, Florida Before and After Hurricane Ivan, September 2004

    NASA Astrophysics Data System (ADS)

    Vaughan, C.; Briggs, K. B.; Richardson, M. D.

    2005-05-01

    A 6-km2 area immediately offshore of Santa Rosa Island, Florida in 5-15-m water depth was surveyed with a 300-kHz side-scan sonar as part of the Coastal Dynamics in Heterogeneous Sedimentary Environments research initiative funded by the Office of Naval Research. Side-scan sonar observations were made five days before and five days after Hurricane Ivan made landfall approximately 100 km to the west of the study location in September 2004. The sonar observations made prior to the hurricane indicate a mostly sand bottom that included areas of uniform, small-scale wind-wave ripple morphology occurring mostly in the deeper regions of the western half of the survey area. The ripple orientation is shore-normal, with the crests and troughs essentially extending E-W. The ripple morphology is less prominent in the eastern half of the surveyed area and not apparent in the more shallow areas, consisting mostly of little apparent bottom structure. Imagery also show two distinct areas of low backscatter trending NW-SE through the survey area that appear to be mud swales. The obvious morphology change as a result of Hurricane Ivan was the widespread formation of low-backscatter patches that give the imagery a mottled texture. These patches vary in size and shape, but 25 m2 is typical. Diver observations in an area about 5 km to the east of the study site confirmed the existence of mud deposits, or mud-filled depressions. These mud deposits range in thickness from thin, 2-cm layers up to 15-cm deposits. Outflow from the lagoonal areas behind barrier islands after the passage of the hurricane likely supplied the mud that pooled in bathymetric depressions. Also, post-hurricane sonographs show more prominent wave ripples with larger crestal spacings and amplitude, but similar to pre-hurricane sonographs, ripples were less uniform to non-existent in the shallow areas. The mud swale formations remained and are better defined in the imagery after the hurricane. Particle-size analysis

  13. Side scan sonar image segmentation based on neutrosophic set and quantum-behaved particle swarm optimization algorithm

    NASA Astrophysics Data System (ADS)

    Zhao, Jianhu; Wang, Xiao; Zhang, Hongmei; Hu, Jun; Jian, Xiaomin

    2016-09-01

    To fulfill side scan sonar (SSS) image segmentation accurately and efficiently, a novel segmentation algorithm based on neutrosophic set (NS) and quantum-behaved particle swarm optimization (QPSO) is proposed in this paper. Firstly, the neutrosophic subset images are obtained by transforming the input image into the NS domain. Then, a co-occurrence matrix is accurately constructed based on these subset images, and the entropy of the gray level image is described to serve as the fitness function of the QPSO algorithm. Moreover, the optimal two-dimensional segmentation threshold vector is quickly obtained by QPSO. Finally, the contours of the interested target are segmented with the threshold vector and extracted by the mathematic morphology operation. To further improve the segmentation efficiency, the single threshold segmentation, an alternative algorithm, is recommended for the shadow segmentation by considering the gray level characteristics of the shadow. The accuracy and efficiency of the proposed algorithm are assessed with experiments of SSS image segmentation.

  14. How effectively do horizontal and vertical response strategies of long-finned pilot whales reduce sound exposure from naval sonar?

    PubMed

    Wensveen, Paul J; von Benda-Beckmann, Alexander M; Ainslie, Michael A; Lam, Frans-Peter A; Kvadsheim, Petter H; Tyack, Peter L; Miller, Patrick J O

    2015-05-01

    The behaviour of a marine mammal near a noise source can modulate the sound exposure it receives. We demonstrate that two long-finned pilot whales both surfaced in synchrony with consecutive arrivals of multiple sonar pulses. We then assess the effect of surfacing and other behavioural response strategies on the received cumulative sound exposure levels and maximum sound pressure levels (SPLs) by modelling realistic spatiotemporal interactions of a pilot whale with an approaching source. Under the propagation conditions of our model, some response strategies observed in the wild were effective in reducing received levels (e.g. movement perpendicular to the source's line of approach), but others were not (e.g. switching from deep to shallow diving; synchronous surfacing after maximum SPLs). Our study exemplifies how simulations of source-whale interactions guided by detailed observational data can improve our understanding about motivations behind behaviour responses observed in the wild (e.g., reducing sound exposure, prey movement).

  15. Detection of mine and minelike objects in forward-looking sonar data with direct sum successive approximation templates

    NASA Astrophysics Data System (ADS)

    Barnes, Christopher F.; Hallenborg, Philip A.; Patel, Snehal; Fisher, Dave

    1999-08-01

    Nearest neighbor classifiers with direct sum successive approximation (DSSA) templates are shown to be effective for detecting and discriminating mines and mine-like objects in forward looking sonar data. DSSA results are demonstrated on data obtained form field measurements with actual mines and calibration targets. The DSSA templates are used in a nearest neighbor classifier that can be characterized as a new type of radial basis function neural network. This neural network is not designed with a preset complexity level as quantified by an a priori determined number of degrees-of-freedom. Rather, the system is constructed incrementally and adds additional degrees-of-freedom as required by the nature of the training data. The neural net system possesses stage structure that result in inherent computational and memory efficiency in searching and storing the DSSA-based radial basis functions.

  16. Lacustrine flow (divers, side scan sonar, hydrogeology, water penetrating radar) used to understand the location of a drowned person

    NASA Astrophysics Data System (ADS)

    Ruffell, Alastair

    2014-05-01

    An unusual application of hydrological understanding to a police search is described. The lacustrine search for a missing person provided reports of bottom-water currents in the lake and contradictory indications from cadaver dogs. A hydrological model of the area was developed using pre-existing information from side scan sonar, a desktop hydrogeological study and deployment of water penetrating radar (WPR). These provided a hydrological theory for the initial search involving subaqueous groundwater flow, focused on an area of bedrock surrounded by sediment, on the lake floor. The work shows the value a hydrological explanation has to a police search operation (equally to search and rescue). With hindsight, the desktop study should have preceded the search, allowing better understanding of water conditions. The ultimate reason for lacustrine flow in this location is still not proven, but the hydrological model explained the problems encountered in the initial search.

  17. Surficial Geologic Interpretation and Sidescan Sonar Imageryof the Sea Floor in West-Central Long Island Sound

    USGS Publications Warehouse

    McMullen, K.Y.; Poppe, L.J.; Paskevich, V.F.; Doran, E.F.; Moser, M.S.; Christman, E.B.; Beaver, A.L.

    2005-01-01

    INTRODUCTION The United States Geological Survey (USGS) is working cooperatively with the National Oceanic and Atmospheric Administration (NOAA) and Connecticut Department of Environmental Protection (CT-DEP) to conduct detailed studies of the surficial geology in Long Island Sound (LIS). The study goals are to interpret sedimentary environments within the Sound, to further understand processes controlling sediment distribution, and to provide a framework for future studies. Sidescan-sonar mosaics produced by USGS and NOAA show detailed acoustic images of the sea floor with 1-m resolution. These images, along with data obtained from sediment samples, seismic-reflection profiles, and seafloor video, are used to interpret the surficial geology. As part of this cooperative program, since 1995, 12 sidescan-sonar surveys of the LIS sea floor have been completed (Poppe and others, 1997; Twichell and others, 1997; Poppe and others, 1998a; Poppe and others, 1998b; Twichell and others, 1998; Poppe and others, 1999a; Poppe and others, 1999b; Poppe and others, 2001; Poppe and others, 2004; Zajac and others, 2003). The purpose of this report is to release digital versions of the imagery and interpretations from NOAA survey H11044 originally published in McMullen and others (2005). Survey H11044, which covers an area of 293 km2 in west-central LIS, includes the area of the previously published Milford Survey (Twichell and others, 1998) and the westernmost part of the New Haven Harbor Survey (Poppe and others, 2001). These two surveys detailed surficial geology and mapped sediment distributions. In this study, we map the sediment distribution across a broader, previously unstudied area and the sedimentary environments.

  18. The IMI-30 Seafloor Imaging System: Development of A New NSF Deep-Towed 30kHz Bathymetric Sidescan Sonar System

    NASA Astrophysics Data System (ADS)

    Rognstad, M.; Appelgate, B.; Ericksen, T.

    2003-12-01

    The Hawai`i Mapping Research Group (HMRG) has been funded by the U.S. National Science Foundation (OCE-0097822 ) to build and operate a new deep-towed 30kHz phase-difference bathymetric sidescan sonar, the Imaging & Mapping Instrument - 30kHz (IMI-30) . IMI-30 will simultaneously acquire sidescan sonar imagery, phase difference bathymetry, and multibeam subbottom data, with the ability to host other user-supplied instruments as well. Construction of IMI-30 began in early 2003, and the first funded research survey using the system is anticipated to be scheduled in 2004. Here we discuss the planned capabilities of the system, describe the current state of development, and present results from recent test cruises. The IMI-30 design is functionally similar to the HAWAII MR1 and DSL-120 towed sonars, sharing fundamental electronic characteristics, data acquisition computers, and sonar processing software. These shared characteristics allow hardware, software, and support staff to be shared between these systems, resulting in lower operational costs and a larger pool of engineers, technicians and scientists familiar with the maintenance, operation, and data processing requirements of this family of sonars. IMI-30 is fully portable for use on UNOLS global- or ocean-class vessels. Once operational, IMI-30 will be available to all NSF-funded researchers as an NSF facility maintained as part of the University of Hawai`i shared-use equipment pool. Transducers for IMI-30 were fabricated in-house using surplus United States Navy DT605 hydrophones recovered from decommissioned Sturgeon-class submarines. These transducers were designed for use at 30 kHz, and are of an advanced design with multiple element ceramic stacks and exotic materials for head and tail masses. To create long arrays we encapsulated parts of the DT605 array in smaller modules, and tested the sample modules at the Acoustic Test Facility at the Naval Undersea Warfare Center in Keyport, WA. We compared the

  19. SoNar, a Highly Responsive NAD+/NADH Sensor, Allows High-Throughput Metabolic Screening of Anti-tumor Agents.

    PubMed

    Zhao, Yuzheng; Hu, Qingxun; Cheng, Feixiong; Su, Ni; Wang, Aoxue; Zou, Yejun; Hu, Hanyang; Chen, Xianjun; Zhou, Hai-Meng; Huang, Xinzhi; Yang, Kai; Zhu, Qian; Wang, Xue; Yi, Jing; Zhu, Linyong; Qian, Xuhong; Chen, Lixin; Tang, Yun; Loscalzo, Joseph; Yang, Yi

    2015-05-05

    The altered metabolism of tumor cells confers a selective advantage for survival and proliferation, and studies have shown that targeting such metabolic shifts may be a useful therapeutic strategy. We developed an intensely fluorescent, rapidly responsive, pH-resistant, genetically encoded sensor of wide dynamic range, denoted SoNar, for tracking cytosolic NAD(+) and NADH redox states in living cells and in vivo. SoNar responds to subtle perturbations of various pathways of energy metabolism in real time, and allowed high-throughput screening for new agents targeting tumor metabolism. Among > 5,500 unique compounds, we identified KP372-1 as a potent NQO1-mediated redox cycling agent that produced extreme oxidative stress, selectively induced cancer cell apoptosis, and effectively decreased tumor growth in vivo. This study demonstrates that genetically encoded sensor-based metabolic screening could serve as a valuable approach for drug discovery.

  20. Using side scan sonar data in a geographic information system to locate and display lake trout spawning habitat in the Great Lakes

    USGS Publications Warehouse

    Brown, Charles L.; Edsall, Thomas A.; Waltermire, Robert G.; White, Barbara

    1988-01-01

    The National Fisheries Research Center-Great Lakes of the U.S. Fish and Wildlife Service has extensively used a side scan sonar to survey and pinpoint lake trout spawning grounds in the Great Lakes. The Geographic Information System (GIS) of the National Ecology Research Center produced maps from the side scan sonar data showing the exact location of the spawning grounds; this will enable current stocking programs to be carried out at those locations. These maps show the geographic position (latitude and longitude) of both the color-coded primary substrate types and the secondary substrate types, which are denoted by overstrikes. The maps must be supplemented with a Loran-C navigation grid for field use. The maps are proving useful to fishery managers by locating lake trout stocking areas in Lakes Michigan and Huron, as well as to researchers who investigate habitat quality on lake trout spawning grounds.

  1. Burial and exhumation of temperate bedrock reefs as elucidated by repetitive high-resolution sea floor sonar surveys: Spatial patterns and impacts to species' richness and diversity

    USGS Publications Warehouse

    Storlazzi, Curt D.; Fregoso, Theresa A.; Figurski, Jared D.; Freiwald, Jan; Lonhart, Steve I.; Finlayson, David P.

    2013-01-01

    To understand how chronic sediment burial and scour contribute to variation in the structure of algal and invertebrate communities on temperate bedrock reefs, the dynamics of the substrate and communities were monitored at locations that experience sand inundation and adjacent areas that do not. Co-located benthic scuba-transect surveys and high-resolution swath-sonar surveys were completed on bedrock reefs on the inner shelf of northern Monterey Bay, CA, in early winter 2009, spring 2010, and summer 2010. Analysis of the sonar surveys demonstrates that during the 8 months over which the surveys were conducted, 19.6% of the study area was buried by sand while erosion resulted in the exposure of bedrock over 13.8% of the study area; the remainder underwent no change between the surveys. Substrate classifications from the benthic transect surveys correlated with classifications generated from the sonar surveys, demonstrating the capacity of high-resolution sonar surveys to detect burial of bedrock reefs by sediment. On bedrock habitat that underwent burial and exhumation, species' diversity and richness of rock-associated sessile and mobile organisms were 50–66% lower as compared to adjacent stable bedrock habitat. While intermediate levels of disturbance can increase the diversity and richness of communities, these findings demonstrate that burial and exhumation of bedrock habitat are sources of severe disturbance. We suggest that substrate dynamics must be considered when developing predictions of benthic community distributions based on sea floor imagery. These results highlight the need for predictive models of substrate dynamics and for a better understanding of how burial and exhumation shape benthic communities.

  2. Utilizing new multibeam sonar datasets to map potential locations of sensitive benthic habitats in the U.S. Atlantic Extended Continental Shelf

    NASA Astrophysics Data System (ADS)

    Sowers, D.; Mayer, L. A.; Gardner, J. V.

    2013-12-01

    Recently completed multibeam sonar datasets of the U.S. Atlantic Extended Continental Shelf (ECS) area provide bathymetry and acoustic backscatter data that can be utilized in combination with other oceanographic data to help identify Habitats of Particular Concern (HAPCs), such as deepwater corals. Multibeam sonar data was collected by the University of New Hampshire's Center for Coastal and Ocean Mapping/Joint Hydrographic Center (CCOM/JHC) on four different cruises between 2004-2012, and by multiple cruises of the NOAA ship Okeanos Explorer between 2011-2013. These two new multibeam sonar datasets provide a historic new level of detail to our understanding of the Northwest Atlantic seafloor from Florida to the Canadian maritime boundary and from the edge of the continental shelf to the deep ocean. CCOM/JHC has embarked on a research effort to evaluate ways in which to use the new multibeam data sets from the Atlantic Margin, along with other existing ancillary datasets, to generate marine ecological classification maps and potential habitat prediction maps useful for supporting Ecosystem-Based Management. The initial component of this work involves processing the data using QPS Fledermaus and ESRI ArcGIS software to derive sediment classification predictions and terrain descriptors. Substrate characterization and thematic classifications derived using the 'GEOCODER' code from CCOM/JHC are used in combination with seafloor groundtruth data and oceanographic model output to identify potential habitat areas. Bathymetry and backscatter datasets collected with different sonar systems of varying resolution are compared to examine differences in interpreted properties of seafloor substrates within areas of overlapping hydrographic surveys. Results of this work are intended to substantially improve predictive models of potential coldwater coral distribution in the Atlantic ECS area. Future phases of this research effort will apply NOAA's Coastal and Marine Ecological

  3. Does Computer Based Training Impact Maintenance Costs and Actions? An Empirical Analysis of the U.S. Navy’s AN/SQQ-89(v) Sonar System

    DTIC Science & Technology

    2014-04-30

    network of sonar systems designed to search, detect, classify, and engage ASW threats (Lockheed Martin , 2009) 4 For further information on...Lockheed Martin , 2009). The system is currently installed on CG-47 class cruisers, DDG-51 class destroyers, and FFG-7 class frigates. The AN/SQQ- 89...7 SHIP HOMEPORT DDG 64 CARNEY Mayport, FL FFG 49 ROBERT G BRADLEY Mayport, FL CG 66 HUE CITY Mayport, FL DDG 65 BENFOLD San Diego, CA FFG 53 HAWES

  4. Application of Fisher fusion techniques to improve the individual performance of sonar computer-aided detection/computer-aided classification (CAD/CAC) algorithms

    NASA Astrophysics Data System (ADS)

    Ciany, Charles M.; Zurawski, William C.

    2009-05-01

    Raytheon has extensively processed high-resolution sidescan sonar images with its CAD/CAC algorithms to provide classification of targets in a variety of shallow underwater environments. The Raytheon CAD/CAC algorithm is based on non-linear image segmentation into highlight, shadow, and background regions, followed by extraction, association, and scoring of features from candidate highlight and shadow regions of interest (ROIs). The targets are classified by thresholding an overall classification score, which is formed by summing the individual feature scores. The algorithm performance is measured in terms of probability of correct classification as a function of false alarm rate, and is determined by both the choice of classification features and the manner in which the classifier rates and combines these features to form its overall score. In general, the algorithm performs very reliably against targets that exhibit "strong" highlight and shadow regions in the sonar image- i.e., both the highlight echo and its associated shadow region from the target are distinct relative to the ambient background. However, many real-world undersea environments can produce sonar images in which a significant percentage of the targets exhibit either "weak" highlight or shadow regions in the sonar image. The challenge of achieving robust performance in these environments has traditionally been addressed by modifying the individual feature scoring algorithms to optimize the separation between the corresponding highlight or shadow feature scores of targets and non-targets. This study examines an alternate approach that employs principles of Fisher fusion to determine a set of optimal weighting coefficients that are applied to the individual feature scores before summing to form the overall classification score. The results demonstrate improved performance of the CAD/CAC algorithm on at-sea data sets.

  5. Prototype Task Network Model to Simulate the Analysis of Narrow Band Sonar Data and the Effects of Automation on Critical Operator Tasks

    DTIC Science & Technology

    2016-06-07

    task of building the underwater maritime picture depends heavily on the accurate and timely analysis of sonar acoustic data that may be highly...uncertain in origin and embedded in background “noise” from a variety of underwater acoustic sources. The task of distinguishing signal from noise and...time course of many contacts is sufficiently slow, which, in itself, does not produce time stress upon operators, the large volume of acoustic data

  6. Assessing Beaked Whale Reproduction and Stress Response Relative to Sonar Activity at the Atlantic Undersea Test and Evaluation Center AUTEC

    DTIC Science & Technology

    2013-09-30

    selection of beaked whales. Thesis presented for Master’s of Science degree in Zoology at University of Aberdeen, Scotland, UK. 119 pp. DiMarzio, N., D...biopsy samples. Canadian Journal of Zoology . 79, 1442-1454. Kellar, N. M. et al. (2006) Determining pregnancy from blubber in three species of

  7. Assessing Beaked Whale Reproduction and Stress Response Relative to Sonar Activity at the Atlantic Undersea Test and Evaluation Center (AUTEC)

    DTIC Science & Technology

    2012-01-01

    Approved for public release, distribution unlimited 13. SUPPLEMENTARY NOTES The original document contains color images. 14. ABSTRACT 15. SUBJECT TERMS...localized in real time by passive acoustic detection of their echolocation clicks (DiMarzio et al. 2008). Acoustic technicians from the Naval Undersea...Warfare Center relay real-time cetacean localizations using the marine mammal monitoring system at AUTEC and direct observers on a 6.8 m rigid-hulled

  8. 76 FR 4637 - Taking and Importing Marine Mammals; U.S. Navy's Atlantic Fleet Active Sonar Training

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-26

    ... acoustic monitoring. Surveys are conducted year- round using established track lines and standard distance... and JAX; however, in JAX no surveys were flown during April and May due to adverse weather conditions... for the diving and acoustic behavior of each whale. These include time-depth profiles for the...

  9. 77 FR 6080 - Taking and Importing Marine Mammals; U.S. Navy's Atlantic Fleet Active Sonar Training

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-07

    ... acoustic monitoring. Surveys are conducted year- round using established track lines and standard distance... metrics for the diving and acoustic behavior of each whale. These include time- depth profiles for the..., Louisiana. Passive Acoustic Monitoring and Acoustic Analysis Two passive acoustic systems were used...

  10. Interaction of emitted sonar pulses and simulated echoes in a false killer whale: an evoked-potential study.

    PubMed

    Supin, Alexander Ya; Nachtigall, Paul E; Breese, Marlee

    2011-09-01

    Auditory evoked potentials (AEP) were recorded during echolocation in a false killer whale Pseudorca crassidens. An electronically synthesized and played-back (simulated) echo was triggered by an emitted biosonar pulse, and its intensity was proportional to that of the emitted click. The delay and transfer factor of the echo relative to the emitted click was controlled by the operator. The echo delay varied from 2 to 16 ms (by two-fold steps), and the transfer factor varied within ranges from -45 to -30 dB at the 2-ms delay to -60 to -45 dB at the 16-ms delay. Echo-related AEPs featured amplitude dependence both on echo delay at a constant transfer factor (the longer the delay, the higher amplitude) and on echo transfer factor at a constant delay (the higher transfer factor, the higher amplitude). Conjunctional variation of the echo transfer factor and delay kept the AEP amplitude constant when the delay to transfer factor trade was from -7.1 to -8.4 dB per delay doubling. The results confirm the hypothesis that partial forward masking of the echoes by the preceding emitted sonar pulses serves as a time-varying automatic gain control in the auditory system of echolocating odontocetes.

  11. Imaging capability of the higher-frequency subsystem of a dual-frequency acoustic lens sonar system

    NASA Astrophysics Data System (ADS)

    Lopes, Joseph L.; Paustian, Iris C.; Marciniak, Robert; Van Tol, Dave; Folds, Donald L.

    2000-07-01

    An experimental dual-frequency acoustic lens sonar system, designed to detect both buried and non-buried objects is described with emphasis on the higher frequency subsystem. The lower frequency subsystem (35 - 100 kHz) forms conical beams with beam widths near 5 degree(s) using discrete transducer elements in the lens focal plane for both transmission and reception. The higher frequency (1 - 2 MHz) lens system is designed to be contained within the volume of the lower frequency subsystem to create a compact dual-frequency system. The higher frequency system consists of three 20-cm long cylindrical lenses designed to form fan-shaped beams over a 20 degree(s) field of view. The retina is positioned 34 cm from the entrance aperture. A test array containing several discrete elements with 1.0-mm pitch has been designed for initial testing. The final system will use a retina with 80 - 100 elements. The imaging system is designed to generate images with cross-range resolutions from 0.1 degree(s) to 0.25 degree(s), and is designed to be tested in both bistatic or monostatic modes. In the monostatic mode, results of spatial multiplexing of beams in the ratio of 3, 4, and 5 will be compared. The system is designed to make a thorough parametric evaluation of imaging in the 1 - 2 MHz range over a wide range of angular resolutions and to relate design parameters to operational performance for forward looking systems.

  12. Mapping the Gulf of Maine with side-scan sonar: A new bottom-type classification for complex seafloors

    USGS Publications Warehouse

    Barnhardt, W.A.; Kelley, J.T.; Dickson, S.M.; Belknap, D.F.

    1998-01-01

    The bedrock-framed seafloor in the northwestern Gulf of Maine is characterized by extreme changes in bathymetric relief and covered with a wide variety of surficial materials. Traditional methods of mapping cannot accurately represent the great heterogeneity of such a glaciated region. A new mapping scheme for complex seafloors, based primarily on the interpretation of side-scan sonar imagery, utilizes four easily recognized units: rock, gravel, sand and mud. In many places, however, the seafloor exhibits a complicated mixture or extremely 'patchy' distribution of the four basic units, which are too small to map individually. Twelve composite units, each a two-component mixture of the basic units, were established to represent this patchiness at a small scale (1:100,000). Using a geographic information system, these and all other available data (seismic profiles, grab samples, submersible dives and cores) were referenced to a common geographic base, superimposed on bathymetric contours and then integrated into surficial geologic maps of the regional inner continental shelf. This digital representation of the seafloor comprises a multidimensional, interactive model complete with explicit attributes (depth, bottom type) that allow for detailed analysis of marine environments.

  13. Surficial geology of the sea floor in west-central Long Island Sound as shown by sidescan-sonar imagery

    USGS Publications Warehouse

    McMullen, K.Y.; Poppe, L.J.; DiGiacomo-Cohen, M. L.; Moser, M.S.; Christman, E.B.

    2005-01-01

    We used sidescan-sonar imagery detailing almost 300 km2 of the sea floor in west-central Long Island Sound in conjunction with bathymetry, sediment samples, bottom video, and seismic data to interpret the area's surficial geology. The distribution of sediments and sedimentary environments interpreted from these data sets represents the Quaternary geology, regional bathymetry, and effects of modern tidal- and wave-driven currents. Four distinct sedimentary environments consisting of 1) fine-grained deposition, 2) sorting and reworking, 3) coarse-grained bedload transport, and 4) erosion or nondeposition, were identified and mapped. Relatively low-energy environments prevail where deposition of clayey silts occurs in deeper water throughout the central part of the study area, and in the protected areas of the far northeastern corner. As low-energy environments transition to relatively high-energy environments, sorting and reworking of sand, silty sand, and sand-silt-clay takes place on the flanks of the shoals and over smaller bathymetric highs. Environments of coarse-grained bedload transport, distinguished by sandy sediments with current-derived bedforms, are located on an unnamed shoal in the northwestern part of the study area and directly to the south of this on Stratford Shoal. High-energy conditions are reflected by environments of erosion or nondeposition, which occur on bathymetric highs where gravel and gravelly sediments are present.

  14. Evaluation of a Single-Beam Sonar System to Map Seagrass at Two Sites in Northern Puget Sound, Washington

    USGS Publications Warehouse

    Stevens, Andrew W.; Lacy, Jessica R.; Finlayson, David P.; Gelfenbaum, Guy

    2008-01-01

    Seagrass at two sites in northern Puget Sound, Possession Point and nearby Browns Bay, was mapped using both a single-beam sonar and underwater video camera. The acoustic and underwater video data were compared to evaluate the accuracy of acoustic estimates of seagrass cover. The accuracy of the acoustic method was calculated for three classifications of seagrass observed in underwater video: bare (no seagrass), patchy seagrass, and continuous seagrass. Acoustic and underwater video methods agreed in 92 percent and 74 percent of observations made in bare and continuous areas, respectively. However, in patchy seagrass, the agreement between acoustic and underwater video was poor (43 percent). The poor agreement between the two methods in areas with patchy seagrass is likely because the two instruments were not precisely colocated. The distribution of seagrass at the two sites differed both in overall percent vegetated and in the distribution of percent cover versus depth. On the basis of acoustic data, seagrass inhabited 0.29 km2 (19 percent of total area) at Possession Point and 0.043 km2 (5 percent of total area) at the Browns Bay study site. The depth distribution at the two sites was markedly different. Whereas the majority of seagrass at Possession Point occurred between -0.5 and -1.5 m MLLW, most seagrass at Browns Bay occurred at a greater depth, between -2.25 and -3.5 m MLLW. Further investigation of the anthropogenic and natural factors causing these differences in distribution is needed.

  15. Measurements of near-surface bubble plumes in the open ocean with implications for high-frequency sonar performance.

    PubMed

    Trevorrow, Mark V

    2003-11-01

    This study examines near-surface bubble data obtained with a self-contained 200-kHz inverted echo-sounder deployed at Ocean Station Papa (NE Pacific, 1400 km west of Vancouver Is.) over an 81-day period in the spring of 1996. The instrument operated continuously, recording calibrated volume scattering profiles from near-surface bubbles with 3-s and 30-cm resolution. The data show the frequent occurrence of bubbles organized into vertical, plume-like structures, presumably drawn downwards by turbulence and other near-surface circulations. Average bubble plume penetrations of up to 15 m were observed, with maximum penetrations up to 25 m. Within the plumes, the backscatter cross section exhibited an exponential decay with depth, with e-folding scale in the range 0.5 to 3 m, increasing proportionally to the square of average plume depth. Using standard models for bubble scattering, and incorporating recent acoustic resonator measurements of bubble-size distributions along with actual bubble plume data, high-frequency near-surface sonar performance models were developed. These models show that on a ping-to-ping basis the bubble plume structures can induce significant spatial variations in the reverberation level and path-integrated extinction losses to near-surface targets.

  16. On doing two things at once: dolphin brain and nose coordinate sonar clicks, buzzes and emotional squeals with social sounds during fish capture.

    PubMed

    Ridgway, Sam; Samuelson Dibble, Dianna; Van Alstyne, Kaitlin; Price, DruAnn

    2015-12-01

    Dolphins fishing alone in open waters may whistle without interrupting their sonar clicks as they find and eat or reject fish. Our study is the first to match sound and video from the dolphin with sound and video from near the fish. During search and capture of fish, free-swimming dolphins carried cameras to record video and sound. A hydrophone in the far field near the fish also recorded sound. From these two perspectives, we studied the time course of dolphin sound production during fish capture. Our observations identify the instant of fish capture. There are three consistent acoustic phases: sonar clicks locate the fish; about 0.4 s before capture, the dolphin clicks become more rapid to form a second phase, the terminal buzz; at or just before capture, the buzz turns to an emotional squeal (the victory squeal), which may last 0.2 to 20 s after capture. The squeals are pulse bursts that vary in duration, peak frequency and amplitude. The victory squeal may be a reflection of emotion triggered by brain dopamine release. It may also affect prey to ease capture and/or it may be a way to communicate the presence of food to other dolphins. Dolphins also use whistles as communication or social sounds. Whistling during sonar clicking suggests that dolphins may be adept at doing two things at once. We know that dolphin brain hemispheres may sleep independently. Our results suggest that the two dolphin brain hemispheres may also act independently in communication.

  17. Sedimentary features of the south Texas continental slope as revealed by side-scan sonar and high-resolution seismic data

    SciTech Connect

    Rothwell, R.G.; Kenyon, N.H. ); McGregor, B.A. )

    1991-02-01

    Sedimentary provinces on the south Texas slope have been identified by their acoustic character on long-range side-scan sonar records and high-resolution seismic profiles. Probable lithofacies within these provinces have been identified by core data and by analogy with previously cored acoustic facies. In the northern part of the study area, the East Breaks Slide is a prominent mass-transport feature. Revised bathymetry shows that the slide originated on the upper slope (200-1,000 m), in front of a sandy late Wisconsinan shelf-margin delta, where the gradient is up to 3{degree}. Side-scan sonar data indicates that the slide is a strongly backscattering feature extending more than 110 km downslope from the shelf edge. it consists of two lobes that are separated by a diapiric high. Diapiric highs on the middle slope have blocked most of the flow. borehole data shows that the slide deposit contains intercalated sands and contorted bedding. The slide is therefore attributed to failure of sandy deltaic material deposited close to the shelf edge during the last period of low sea level (late Wisconsinan, circa 11-29 Ka). Core data suggests that the weakly backscattering acoustic facies adjacent to the slide are fine-grained sediments (mudturbidites and hemipelagites) of a slope mud drape. The middle slope in front of the sandy late Wisconsinan shelf-margin delta of the Rio Grande has an intermediate level of backscattering with numerous channels leading to the Sigsbee Deep. Acoustic facies mapping using long-range side-scan sonar matches well with acoustic facies mapping using 3.5-kHz high-resolution seismic profiles.

  18. Quaternary sedimentary processes on the northwestern African continental margin - An integrated study using side-scan sonar, high-resolution profiling, and core data

    SciTech Connect

    Masson, D.G.; Huggett, Q.J.; Weaver, P.P.E. ); Kidd, R.B. ); Gardner, J.V. )

    1991-08-01

    Side-scan sonar data, cores, and high-resolution profiles have been used to produce an integrated model of sedimentation for the continental margin west of the Canary Islands. Long-range side-scan sonar (GLORIA) data and a grid of 3.5-kHz profiles, covering some 200,000 km{sup 2} allow a regional appraisal of sedimentation. More detailed studies of selected areas have been undertaken using a new 30 kHz deep-towed side-scan sonar (TOBI) developed by the U.K. Institute of Oceanographic Sciences. Sediment cores have been used both to calibrate acoustic facies identified on sonographs and for detailed stratigraphic studies. The most recent significant sedimentation event in the area is to Saharan Sediment Slide, which carried material from the upper continental slope off West Africa to the edge of the Madeira Abyssal Plain, a distance of some 1000 km. The authors data shows the downslope evolution of the debris flow. Near the Canaries, it is a 20-m-thick deposit rafting coherent blocks of more than 1 km diameter; side-scan records show a strong flow-parallel fabric on a scale of tens of meters. On the lower slope, the debris flow thins to a few meters, the flow fabric disappears, and the rafted blocks decrease to meters in diameter. Side-scan data from the lower slope show that the Saharan Slide buries an older landscape of turbidity current channels, typically 1 km wide and 50 m deep. Evidence from the Madeiran Abyssal Plain indicates a history of large but infrequent turbidity currents, the emplacement of which is related to the effects of sea level changes on the northwest African margin.

  19. Use of a high-resolution profiling sonar and a towed video camera to map a Zostera marina bed, Solent, UK

    NASA Astrophysics Data System (ADS)

    Lefebvre, A.; Thompson, C. E. L.; Collins, K. J.; Amos, C. L.

    2009-04-01

    Seagrasses are flowering plants that develop into extensive underwater meadows and play a key role in the coastal ecosystem. In the last few years, several techniques have been developed to map and monitor seagrass beds in order to protect them. Here, we present the results of a survey using a profiling sonar, the Sediment Imager Sonar (SIS) and a towed video sledge to study a Zostera marina bed in the Solent, southern UK. The survey aimed to test the instruments for seagrass detection and to describe the area for the first time. On the acoustic data, the bed produced the strongest backscatter along a beam. A high backscatter above the bottom indicated the presence of seagrass. The results of an algorithm developed to detect seagrass from the sonar data were tested against video data. Four parameters were calculated from the SIS data: water depth, a Seagrass Index (average backscatter 10-15 cm above the bed), canopy height (height above the bed where the backscatter crosses a threshold limit) and patchiness (percentage of beams in a sweep where the backscatter 10-15 cm above the bed is greater than a threshold limit). From the video, Zostera density was estimated together with macroalgae abundance and bottom type. Patchiness calculated from the SIS data was strongly correlated to seagrass density evaluated from the video, indicating that this parameter could be used for seagrass detection. The survey area has been classified based upon seagrass density, macroalgae abundance and bottom type. Only a small area was occupied by a dense canopy whereas most of the survey area was characterised by patchy seagrass. Results indicated that Zostera marina developed only on sandy bottoms and was not found in regions of gravel. Furthermore, it was limited to a depth shallower than 1.5 m below the level of Lowest Astronomical Tide and present in small patches across the intertidal zone. The average canopy height was 15 cm and the highest density was 150 shoots m -2.

  20. Shallow-water imaging multibeam sonars: A new tool for investigating seafloor processes in the coastal zone and on the continental shelf

    NASA Astrophysics Data System (ADS)

    Hughes Clarke, John E.; Mayer, Larry A.; Wells, David E.

    1996-12-01

    Hydrographic quality bathymetry and quantitative acoustic backscatter data are now being acquired in shallow water on a routine basis using high frequency multibeam sonars. The data provided by these systems produce hitherto unobtainable information about geomorphology and seafloor geologic processes in the coastal zone and on the continental shelf. Before one can use the multibeam data for hydrography or quantitative acoustic backscatter studies, however, it is essential to be able to correct for systematic errors in the data. For bathymetric data, artifacts common to deep-water systems (roll, refraction, positioning) need to be corrected. In addition, the potentially far greater effects of tides, heave, vessel lift/squat, antenna motion and internal time delays become of increasing importance in shallower water. Such artifacts now cause greater errors in hydrographic data quality than bottom detection. Many of these artifacts are a result of imperfect motion sensing, however, new methods such as differential GPS hold great potential for resolving such limitations. For backscatter data, while the system response is well characterised, significant post processing is required to remove residual effects of imaging geometry, gain adjustments and water column effects. With the removal of these system artifacts and the establishment of a calibrated test site in intertidal regions (where the seabed may be intimately examined by eye) one can build up a sediment classification scheme for routine regional seafloor identification. When properly processed, high frequency multibeam sonar data can provide a view of seafloor geology and geomorphology at resolutions of as little as a few decimetres. Specific applications include quantitative estimation of sediment transport rates in large-scale sediment waves, volume effects of iceberg scouring, extent and style of seafloor mass-wasting and delineation of structural trends in bedrock. In addition, the imagery potentially provides