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ears and with airtight connections were developed. Moreover, mechanical prediction equipment, given the slow speed of sound as compared to the faster planes, and height corrections provided information to point the searchlight operators and the anti-aircraft gunners to where the detected aircraft flies. Searchlights and guns needed to be at a distance from the listening device. Therefore, electric direction indicator devices were developed.
668:
774:(sound navigation and ranging) is a technique that uses sound propagation under water (or occasionally in air) to navigate, communicate or to detect other vessels. There are two kinds of sonar – active and passive. A single active sonar can localize in range and bearing as well as measuring radial speed. However, a single passive sonar can only localize in bearing directly, though
676:
653:(SRP-PHAT) are usually interpreted as finding the candidate location that maximizes the output of a delay-and-sum beamformer. The method has been shown to be very robust to noise and reverberation, motivating the development of modified approaches aimed at increasing its performance in real-time acoustic processing applications.
648:
Steered response power (SRP) methods are a class of indirect acoustic source localization methods. Instead of estimating a set of time-differences of arrival (TDOAs) between pairs of microphones and combining the acquired estimates to find the source location, indirect methods search for a candidate
727:
End of the 1920s, an operational comparison of multiple large acoustic listening devices from different nations by the
Meetgebouw in The Netherlands showed drawbacks. Fundamental research showed that the human ear is better than one understood in the 20s and 30s. New listening devices closer to the
722:
Sound location equipment in
Germany, 1939. It consists of four acoustic horns, a horizontal pair and a vertical pair, connected by rubber tubes to stethoscope-type earphones worn by the two technicians left and right. The stereo earphones enabled one technician to determine the direction and the
121:
describing their sensitivity as a function of the direction of the incident sound. Many microphones have an omnidirectional polar pattern which means their sensitivity is independent of the direction of the incident sound. Microphones with other polar patterns exist that are more sensitive in a
735:
that were used from World War I through World War II. Sound mirrors normally work by using moveable microphones to find the angle that maximizes the amplitude of sound received, which is also the bearing angle to the target. Two sound mirrors at different positions will generate two different
707:
horns mounted on a rotating pole. Several of these equipments were able to give a fairly accurate fix on the approaching airships, allowing the guns to be directed at them despite being out of sight. Although no hits were obtained by this method, Rawlinson claimed to have forced a
Zeppelin to
747:
began to become a credible alternative to the sound location of aircraft. For typical aircraft speeds of that time, sound location only gave a few minutes of warning. The acoustic location stations were left in operation as a backup to radar, as exemplified during the
122:
certain direction. This however is still no solution for the sound localization problem as one tries to determine either an exact direction, or a point of origin. Besides considering microphones that measure sound pressure, it is also possible to use a
81:
tool, passive acoustic location was used from mid-World War I to the early years of World War II to detect enemy aircraft by picking up the noise of their engines. It was rendered obsolete before and during World War II by the introduction of
74:, when using microphones, are a means of passive acoustic localization, but when using speakers are a means of active localization. Typically, more than one device is used, and the location is then triangulated between the several devices.
109:
source given measurements of the sound field. The sound field can be described using physical quantities like sound pressure and particle velocity. By measuring these properties it is (indirectly) possible to obtain a source direction.
316:
844:
Seismic surveys involve the generation of sound waves to measure underground structures. Source waves are generally created by percussion mechanisms located near the ground or water surface, typically dropped weights,
451:
849:
trucks, or explosives. Data are collected with geophones, then stored and processed by computer. Current technology allows the generation of 3D images of underground rock structures using such equipment.
169:
The traditional method to obtain the source direction is using the time difference of arrival (TDOA) method. This method can be used with pressure microphones as well as with particle velocity probes.
531:
1474:
864:
Because the cost of the associated sensors and electronics is dropping, the use of sound ranging technology is becoming accessible for other uses, such as for locating wildlife.
138:. By measuring particle velocity one obtains a source direction directly. Other more complicated methods using multiple sensors are also possible. Many of these methods use the
60:
acoustic location involves the detection of sound or vibration created by the object being detected, which is then analyzed to determine the location of the object in question.
560:
604:
397:
377:
350:
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transmitters emitting sound at known positions and time, the position of a target equipped with a microphone/ultrasonic receiver can be estimated based on the
194:
640:
For acoustic localization this means that if the source direction is measured at two or more locations in space, it is possible to triangulate its location.
86:, which was far more effective (but interceptable). Acoustic techniques had the advantage that they could 'see' around corners and over hills, due to sound
1078:
Cobos, M.; Marti, A.; Lopez, J. J. (2011). "A Modified SRP-PHAT Functional for Robust Real-Time Sound Source
Localization With Scalable Spatial Sampling".
54:
acoustic location involves the creation of sound in order to produce an echo, which is then analyzed to determine the location of the object in question.
1438:
1199:
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can be used to localize in range, given time. Multiple passive sonars can be used for range localization by triangulation or correlation, directly.
763:
Active locators have some sort of signal generation device, in addition to a listening device. The two devices do not have to be located together.
711:
The air-defense instruments usually consisted of large horns or microphones connected to the operators' ears using tubing, much like a very large
483:. The interaural time difference is the difference in arrival time of a sound between two ears. The interaural time difference is given by
1481:
893:
650:
409:
1225:
699:, who in the autumn of 1916 was commanding a mobile anti-aircraft battery on the east coast of England. He needed a means of locating
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1167:
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44:
waves. Location can take place in gases (such as the atmosphere), liquids (such as water), and in solids (such as in the earth).
691:
Military uses have included locating submarines and aircraft. The first use of this type of equipment was claimed by
Commander
1511:
489:
1291:
829:
692:
1349:
Chan, Y.T; Tsui, W. Y.; So, H. C.; Ching, P. C. (2006). "Time-of-arrival based localization under NLOS Conditions".
718:
1132:
1061:
A High
Accuracy, Low-Latency Technique for Talker Localization in Reverberant Environments using Microphone Arrays
633:
to it from known points at either end of a fixed baseline, rather than measuring distances to the point directly (
923:, listening to the echo of sound pulses to measure the distance to the bottom of the sea, a special case of sonar
731:
Most of the work on anti-aircraft sound ranging was done by the
British. They developed an extensive network of
1589:
1584:
1133:"Submarine tracking using multi-sensor fusion and reactive planning for the positioning of passive sonobuoys"
696:
19:
This article is about sound localization via mechanical or electrical means. For the biological process, see
1192:
637:). The point can then be fixed as the third point of a triangle with one known side and two known angles.
1516:
1392:
John L. Spiesberger (June 2001). "Hyperbolic location errors due to insufficient numbers of receivers".
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480:
139:
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How Far Off Is That German Gun? How 63 German guns were located by sound waves alone in a single day
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911:, the practice of using auditory cues and sound markers to navigate indoor and outdoor spaces
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180:) consisting of at least two probes it is possible to obtain the source direction using the
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is the angle between the baseline of the sensors (ears) and the incident sound, in degrees.
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8:
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917:, animals emitting sound and listening to the echo in order to locate objects or navigate
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908:
798:
311:{\displaystyle R_{x_{1},x_{2}}(\tau )=\sum _{n=-\infty }^{\infty }x_{1}(n)x_{2}(n+\tau )}
161:
Different methods for obtaining either source direction or source location are possible.
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After World War II, sound ranging played no further role in anti-aircraft operations.
153:" in that the measured sound field is translated to the position of the sound source.
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conditions, where there are blockages in between the transmitters and the receivers.
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source location over a grid of spatial points. In this context, methods such as the
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629:, triangulation is the process of determining the location of a point by measuring
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752:. Today, the abandoned sites are still in existence and are readily accessible.
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is a method of determining the position of an object or sound source by using
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687:(Hirohito) inspecting military acoustic locators mounted on 4-wheel carriages
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is the speed of sound in the medium surrounding the sensors and the source.
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A three-dimensional echo-sounding representation of a canyon under the
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1034:"Acoustic Source Localization based on independent component analysis"
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during cloudy conditions and improvised an apparatus from a pair of
379:. In general, a higher level of correlation means that the argument
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446:{\displaystyle \tau _{\text{true}}={\frac {d_{\text{spacing}}}{c}}}
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An
Empirical Study of Collaborative Acoustic Source Localization
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directly. The particle velocity is another quantity related to
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Both of these techniques, when used in water, are known as
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https://books.google.com/books?id=EikDAAAAMBAJ&pg=PA39
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monthly, December 1918, page 39, Scanned by Google Books:
675:
403:. For two sensors next to each other the TDOA is given by
794:
584:
is the distance between the two sensors (ears) in meters,
1010:
1013:"Random Gunfire Problems and Gunshot Detection Systems"
1011:
Lorraine Green
Mazerolle; et al. (December 1999).
134:
however, unlike sound pressure, particle velocity is a
105:
Acoustic source localization is the task of locating a
68:; passive sonar and active sonar are both widely used.
945:, the use of ultrasound echoes to look inside the body
1445:
article on French aircraft sound detector with photo.
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1197:, Andrew Melrose, London & New York, pp. 110–114
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526:{\displaystyle \Delta t={\frac {x\cos \theta }{c}}}
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117:is measured using microphones. Microphones have a
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817:of the sound. The accuracy is usually poor under
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1439:"Huge Ear Locates Planes and Tells Their Speed"
1394:The Journal of the Acoustical Society of America
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1168:"Before RADAR – Acoustic Detection of Aircraft"
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804:
188:function between two microphones is defined as
1333:"The Burning Blue: The Battle of Britain 1940"
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33:soldiers operating an acoustic locator in 1940
16:Use of reflected sound waves to locate objects
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1309:
1020:National Institute of Justice Research Brief
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93:Civilian uses include locating wildlife and
47:Location can be done actively or passively:
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651:steered-response power with phase transform
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1324:
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184:function between each probes' signal. The
1331:Lee Brimmicombe Woods (7 December 2005).
1289:
1276:Air acoustics history at Museum Waalsdorp
1107:
934:, the use of echolocation by blind people
1249:
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740:to determine a sound source's position.
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1512:Computational auditory scene analysis
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1463:
1385:
1243:
1226:"Acoustic Location and Sound Mirrors"
1316:Andrew Grantham (November 8, 2005).
1071:
801:to detect prey and avoid obstacles.
723:other the elevation of the aircraft.
708:jettison its bombs on one occasion.
479:A well-known example of TDOA is the
643:
325:between the outputs of two sensors
13:
1292:"Sound Mirrors on the South Coast"
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1004:
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736:bearings, which allows the use of
562:is the time difference in seconds,
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399:is relatively close to the actual
259:
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14:
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1448:Many references can be found in
1351:IEEE Trans. Vehicular Technology
1131:Kristian Johanssan; et al.
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1080:IEEE Signal Processing Letters
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305:
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95:locating the shooting position
1:
1318:"Early warning sound mirrors"
954:
697:Royal Naval Volunteer Reserve
805:Time-of-arrival localization
7:
1517:Music information retrieval
867:
321:which defines the level of
72:Acoustic mirrors and dishes
10:
1616:
1290:Phil Hide (January 2002).
1191:Rawlinson, Alfred (1923),
852:
660:
614:
481:interaural time difference
401:time-difference-of-arrival
165:Time difference of arrival
156:
140:time difference of arrival
100:
18:
1497:
759:Active / passive locators
1252:"Photo of Sound Locator"
1100:10.1109/LSP.2010.2091502
859:
782:Biological echo location
766:
743:As World War II neared,
555:{\displaystyle \Delta t}
149:source localization an "
126:to measure the acoustic
1559:3D sound reconstruction
1363:10.1109/TVT.2005.861207
1058:DiBiase, J. H. (2000).
992:Greenridge Sciences Inc
943:Medical ultrasonography
879:3D sound reconstruction
683:photograph of Japanese
663:Artillery sound ranging
599:{\displaystyle \theta }
124:particle velocity probe
1450:Beamforming References
1214:Rawlinson, pp. 118–119
841:
776:Target Motion Analysis
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1590:Measuring instruments
1585:Anti-aircraft warfare
1554:3D sound localization
1195:The Defence of London
1036:. LMS. Archived from
884:3D sound localization
855:Reflection seismology
832:
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671:T3 sound locator 1927
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392:{\displaystyle \tau }
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372:{\displaystyle x_{2}}
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345:{\displaystyle x_{1}}
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29:
1502:Acoustic fingerprint
1202:May 5, 2016, at the
1067:(Ph.D.). Brown Univ.
949:Sensory substitution
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329:
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1537:Speaker recognition
1406:2001ASAJ..109.3076S
1166:W.Richmond (2003).
1092:2011ISPL...18...71C
988:"Selected Projects"
915:Animal echolocation
909:Acoustic wayfinding
1542:Speech recognition
932:Human echolocation
889:Sound localization
842:
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142:(TDOA) technique.
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21:sound localization
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1549:Sound recognition
1527:Speech processing
1491:Computer audition
1441:Popular Mechanics
1414:10.1121/1.1373442
837:by survey vessel
819:non-line-of-sight
750:Battle of Britain
577:{\displaystyle x}
521:
469:{\displaystyle c}
441:
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186:cross-correlation
182:cross-correlation
145:Some have termed
128:particle velocity
38:Acoustic location
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1595:Sound technology
1532:Speech analytics
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1400:(6): 3076–3079.
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1338:. GMT Games LLC.
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1294:. Archived from
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899:Multilateration
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1507:Audio mining
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1357:(1): 17–24.
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1193:Rawlinson,
1109:10251/55953
713:stethoscope
323:correlation
88:diffraction
79:air defense
1574:Categories
1302:2006-05-13
1262:2006-05-15
1236:2006-06-01
1178:2013-01-06
1149:2006-05-16
1044:2018-01-07
997:2006-05-16
955:References
853:See also:
811:ultrasonic
705:gramophone
661:See also:
1580:Acoustics
1371:0018-9545
894:Boomerang
847:vibroseis
701:Zeppelins
594:θ
547:Δ
515:θ
512:
494:Δ
415:τ
387:τ
303:τ
260:∞
255:∞
252:−
242:∑
232:τ
1422:11425152
1200:Archived
1118:18207534
868:See also
787:Dolphins
627:geometry
147:acoustic
1402:Bibcode
1379:6697621
1088:Bibcode
835:Red Sea
695:of the
434:spacing
172:With a
157:Methods
101:Summary
58:Passive
31:Swedish
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791:whales
631:angles
536:where
456:where
136:vector
52:Active
1375:S2CID
1336:(PDF)
1143:(PDF)
1136:(PDF)
1114:S2CID
1065:(PDF)
1016:(PDF)
860:Other
772:Sonar
767:Sonar
745:radar
107:sound
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66:sonar
42:sound
1418:PMID
1367:ISSN
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