395:, which the Coast and Geodetic Survey planned to commission into its fleet later that year; successful operation of the sonic rangefinder would require a precise understanding of the speed of sound through water. When Heck contacted E. A. Stephenson of the U.S. Army Coast Artillery Corps to inform him of this plan and to inquire further about the Vineyard Sound experiments, Stephenson suggested that a system of hydrophones detecting the sound of underwater explosions could allow Coast and Geodetic Survey ships to fix their position while conducting surveys. Heck agreed, but believed that existing navigation aids would not meet the needs of the Coast and Geodetic Survey in terms of the immediacy and accuracy of position fixes. He envisioned improving on the Submarine Signal Company's system of underwater noise generators and attached radio transmitters, as well as other previous concepts, by creating what would become known as the radio acoustic ranging method. Like echosounding, this method required an accurate calculation of the speed of sound through water.
185:â at a distance from the ship. Each hydrophone was connected to a radio transmitter that automatically sent a signal indicating the time its hydrophone detected the sound. At the distances involved â generally less than 200 nautical miles (370 km) â each of these radio signals arrived at the ship at essentially the same instant that each of the remote hydrophones detected the sound of the explosion. The ship's chronograph automatically recorded the time each radio signal arrived at the ship. By subtracting the time of the explosion from the time of radio signal reception, the ship's crew could determine the length of time the sound wave required to travel from the point of the explosion to each remote hydrophone and, knowing the speed of sound in the surrounding sea water, could multiply the sound's travel time by the velocity of sound in sea water to determine the distance between the explosion and the hydrophone. By determining the distance to at least two remote hydrophones in known locations, the ship's crew could use
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678:"radio-sonobuoys", and in July 1936 it began to place radio-sonobuoys in service. The 700-pound (317.5-kg) buoys â equipped with subsurface hydrophones, batteries, and radio transmitters that automatically sent a radio signal when their hydrophones detected the sound of a ranging explosion â could be deployed or recovered by Coast and Geodetic Survey ships in five minutes. Use of the buoys spread to the U.S. West Coast as well because they were cheaper to set up and operate than a shore station.
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difficulty with getting some of the explosive charges to detonate hampered some of the experimental program. In April 1924, the Coast and
Geodetic Survey concluded that both echo sounding and radio acoustic ranging were fundamentally sound, with no foundational problems left to solve, and that all that remained necessary was continued development and refinement of both techniques during their operational use. Heck turned over continued development of echo sounding and radio acoustic ranging to
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sound waves traveling from the point of the explosion to the distant hydrophones at about 0.8 nautical miles per second (1.5 km/s), ships occasionally used radio acoustic ranging at distances of over 200 nautical miles (370 kilometres) between ship and hydrophone station, and distances of 75 to 100 nautical miles (139 to 185 km) were common.
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handling a bomb lit its fuse and then fell when the ship lurched; he dropped the bomb, which rolled into a gutter. The petty officer fell again before finally reaching the bomb and heaving it overboard just in time; it exploded alongside the ship just as it hit the water. The concussion prompted half
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both tested her new echo sounder's ability to make accurate depth soundings and conducted radio acoustic ranging experiments in cooperation with the U.S. Army Coast
Artillery Corps. Despite many difficulties, testing of both echo sounding and radio acoustic ranging wrapped up successfully in November
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and measured the amount of time it took for the sound to arrive at hydrophones at the other ends of the baselines in order to establish very accurate measurements of the speed of sound through water. And in 1923, the
Submarine Signal Company improved upon its underwater signaling devices by equipping
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levels. She also compared echo sounder soundings with those made by lead lines, discovering that using a single speed of sound through water, as had been the previous practice by those conducting echo sounding experiments, yielded acoustic depth-finding results that did not match the depths found by
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Radio acoustic ranging had limitations and drawbacks. Local peculiarities in the propagation of acoustic waves in the water column could degrade its accuracy, there were problems with maintaining hydrophone stations, and handling explosive charges posed a considerable danger to personnel and ships.
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became the first ship to employ radio acoustic ranging operationally. Off Oregon that year, she successfully employed the technique at a distance of 206 nautical miles (382 kilometres) between the ranging explosion and the remote hydrophones detecting its sound and in the process achieved the first
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invented a submarine bell signalling device and a hydrophone that could serve as a receiver of the underwater sounds the bells generated. The crew of a ship equipped with the receiving hydrophone could plot their ship's distance from the submarine bell mechanism and plot intersecting lines from two
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systems were easier to maintain than hydrophone stations and did not require the handling of explosives and, as the new systems matured, the Coast and
Geodetic Survey began to apply them to maritime navigation. Radio acoustic ranging appears not to have been used after 1944, and by 1946, Coast and
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then conducted experiments off the coast of
California during the early months of 1924 that demonstrated that accurate echo sounding was possible using the new formulas. Experiments with radio acoustic ranging, despite initial difficulties, demonstrated that the method also was practical, although
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made history during the voyage, becoming the first Coast and
Geodetic Survey ship to use echo sounding to measure and record the depth of the sea at points along her course; she also measured water temperatures and took water samples so that the Scripps Institution for Biological Research (now the
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Chronographs recorded times to the hundredth of a second, and the crew of a ship using radio acoustic ranging could determine their ship's distance from the remote hydrophone stations to within 50 feet (15 meters), allowing them to plot their ship's position with great accuracy for the time. With
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The first non-visual method of precise navigation in human history, and the first that could be used at any time of day or night and in any weather conditions, radio acoustic ranging was a major step forward in the development of modern navigation systems. Nicholas Heck revolutionized oceanic
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and to detect an iceberg ahead of a ship at a range of 2 nautical miles (3.7 km; 2.3 mi) by bouncing sound off it and detecting the echo, as well as an occasional ability to detect the reflection of sound off the ocean bottom. Further impetus to developing practical applications of
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often blocked the sound from reaching shore at all. To overcome these difficulties, the Coast and
Geodetic Survey anchored vessels well offshore along the U.S. East Coast to serve as hydrophone stations. In 1931, the Coast and Geodetic Survey proposed replacing the manned station ships with
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them with radio transmitters that sent signals both to identify the particular device and to indicate to approaching ships that it would generate an acoustic signal at a specific time interval after it sent the radio signal, allowing ships to identify the specific
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lead lines. Before she reached San Diego in
December 1923, she had accumulated much data beneficial to the study of the movement of sound waves through water and measuring their velocity under varying conditions of salinity,
45:, was a method for determining a ship's precise location at sea by detonating an explosive charge underwater near the ship, detecting the arrival of the underwater sound waves at remote locations, and
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Radio acoustic ranging had its origins in a growing understanding of underwater acoustics and their practical application during the early decades of the 20th century, and developed in parallel with
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personnel in consultation with the
Scripps Institution developed formulas that allowed accurate echo sounding of depths in all but the shallowest waters and installed hydrophones at La Jolla and
751:. His work related to the technique also helped to develop underwater sound velocity tables allowing the establishment of "true depths" of up to five miles (8.0 km) using echo sounding.
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would pose no challenges. In fact, the opposite proved true: Among other problems, the relatively shallow water along the U.S. East Coast attenuated the sound of ranging explosions and
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to develop a hydrophone system that could automatically send a radio signal when it detected the sound of an underwater explosion. When the Coast and
Geodetic Survey commissioned
272:(1866â1932) to begin work on a long-distance underwater sound transmission and reception system that could detect hazards in the path of a ship. This led to the invention of the
402:, that demonstrated that shipboard recording of the time of an explosion could be performed accurately enough for his concept to work. He worked with Dr. E. A. Eckhardt, a
200:, the Coast and Geodetic Survey could rely upon shore stations to support radio acoustic ranging because the deep water allowed sound to travel to the coast. Along the
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Theberge, Alfred E., "System Without Fixed Points: Development of the Radio-Acoustic Ranging Navigation Technique (Part 1)," hydro-international.com, December 2, 2009.
480:, where she would be based in the future, with her route planned to take her over a wide variety of ocean depths so that she could continue to test her echo sounder.
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they were approaching and to take advantage of a one-way ranging capability that let their crews determine their direction and distance from the navigational aid.
81:, and the first non-visual means to provide precise positions. First employed operationally in 1924, radio acoustic ranging remained in use until 1944, when new
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Initially, Heck and others involved in the development of radio acoustic ranging thought the technique would prove least effective along the coast of the
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aboard the ship automatically recorded the time the explosion was heard at the ship. The sound traveled outward from the explosion, eventually reaching
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in commission in the U.S. Coast and Geodetic Survey fleet from 1923 to 1941. She was the first ship to employ radio acoustic ranging operationally.
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As late as 1942, radio acoustic ranging remained important enough to the Coast and Geodetic Survey for it to devote just over 100 pages of its
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celebrating200years.noaa.gov Top Tens: Breakthroughs: Hydrographic Survey Techniques: Acoustic Survey Methods: Radio Acoustic Ranging
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which by 1914 had a proven ability to transmit and receive sound at a distance of 31 nautical miles (57 km; 36 mi) across
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of sea water in the vicinity of the ship to determine an accurate velocity of sound through the water. The crew then threw a small
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or deep sound channel (DSC). In 1928, French investigators extended this range, detonating a 30-kg (66-pound) explosive in the
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369:(1882â1953), a Coast and Geodetic Survey Corps officer, had been assigned from 1917 to 1919 to World War I service with the
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A 1936 U.S. Coast and Geodetic Survey illustration of a "radio-sonobuoy." The buoys entered service in July of that year.
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The Coast and Geodetic Survey's radio-sonobuoys, developed to support radio acoustic ranging, were the ancestors of the
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systems, and the development of marine seismic surveying. The technique also laid the groundwork for the development of
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A U.S. Coast and Geodetic survey illustration of radio acoustic ranging and echosounding techniques used in combination.
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surveying through the use of radio electronic ranging to establish ship locations, one of his major contributions to
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EVOLUTION OF THE SONOBUOY.pdf Holler, Roger A., "The Evolution of the Sonobuoy From World War II to The Cold War,"
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EVOLUTION OF THE SONOBUOY.pdf Holler, Roger A., "The Evolution of the Sonobuoy From World War II to The Cold War,"
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hydro-international.com Theberge, Albert E., "First Developments of Electronic Navigation Systems," 27 March 2009.
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Radio acoustic ranging was an early step along the path to modern electronic navigation systems, oceanographic
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By January 1923, the Coast and Geodetic Survey had decided to install a Hayes sonic rangefinder â an early
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the time of arrival of the sound waves at the remote stations to the ship, allowing the ship's crew to use
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A 1931 U.S. Coast and Geodetic survey illustration of radio acoustic ranging using anchored station ships.
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To fix their position using radio acoustic ranging, a ship's crew first ascertained the temperature and
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and released the shark, only to watch in horror as it swam back to the ship and exploded next to
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used by ships and aircraft in antisubmarine warfare and underwater acoustic research today.
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NOAA 200th: Hydrographic Survey Techniques: Acoustic Survey Methods: Radio Acoustic Ranging
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bomb off the ship's stern. It exploded at a depth of about 100 feet (30 meters), and a
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in which it detonated explosive charges underwater at the ends of established
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NOAA History: The Start of the Acoustic Work of the Coast and Geodetic Survey
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NOAA History: The Start of the Acoustic Work of the Coast and Geodetic Survey
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or more bells to determine the ship's position. The bells were installed at
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NOAA History: Profiles in Time â C&GS Biographies: Nicholas Hunter Heck
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at known locations â shore stations, anchored station ships, or moored
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frequently interfered with attempts to fix ship positions accurately,
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A U.S. Coast and Geodetic Survey radio acoustic ranging station on
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Heck oversaw tests at Coast and Geodetic Survey headquarters in
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Realizing the potential of these applications of acoustics to
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putting to sea to serve as a hydrophone station ship for the
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Robert Luce, and returned to his duties in Washington, D.C.
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in finding their targets in darkness and bad weather. Such
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to experiment with sound as a means of detecting submerged
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capable of looking ahead of and to the sides of vessels.
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electronic navigation technology to fix their positions.
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inserted a radio acoustic ranging bomb in the mouth of a
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prepares a bomb for use in radio acoustic ranging during
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NOAA History: Tools of the Trade: Radio Acoustic Ranging
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Anonymous, "Ocean's Depth Measured By Radio Robot,"
381:. He was the obvious choice to lead the new effort.
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In deep waters, such as those that prevailed in the
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19:Not to be confused with
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988:
977:
966:
941:
923:
847:
764:
756:telemetering
753:
749:oceanography
745:
723:World War II
718:
716:
706:
699:Hydrographer
698:
690:Hydrographer
689:
680:
664:
634:
624:
606:Hydrographer
605:
595:
544:
519:
514:
506:
504:
481:
470:Panama Canal
461:
459:
448:
436:
427:
415:
397:
391:
386:echo sounder
383:
337:
264:spurred the
256:
248:
236:lightvessels
220:
206:
191:
164:
157:
119:
87:World War II
63:survey ships
42:
38:
34:
33:
1073:Hydrography
688:USC&GS
604:USC&GS
601:survey ship
594:USC&GS
576:operations.
570:survey ship
543:USC&GS
466:Puerto Rico
454:survey ship
447:USC&GS
424:Connecticut
390:USC&GS
287:World War I
232:lighthouses
179:hydrophones
175:chronograph
156:USC&GS
153:survey ship
118:USC&GS
115:survey ship
1057:Categories
804:References
545:Helianthus
478:California
420:New London
344:navigation
303:submarines
291:Royal Navy
278:transducer
217:Precursors
196:along the
103:California
71:navigation
1083:Surveying
1068:Acoustics
767:sonobuoys
633:in 1924,
524:Commander
511:Oceanside
474:San Diego
410:, of the
404:physicist
315:baselines
268:inventor
255:RMS
234:, aboard
93:Technique
773:See also
646:between
495:salinity
491:La Jolla
468:and the
363:officers
266:Canadian
167:salinity
161:in 1929.
158:Surveyor
47:radioing
727:bombers
648:Algiers
500:density
262:iceberg
257:Titanic
251:sinking
65:during
760:sonars
742:Legacy
736:SHORAN
684:ensign
675:shoals
660:France
656:Toulon
631:Oregon
540:launch
520:Guide'
452:was a
431:1923.
297:, and
244:Europe
707:Guide
695:shark
635:Guide
596:Pratt
515:Guide
507:Guide
489:) at
482:Guide
462:Guide
449:Guide
437:Guide
428:Guide
416:Guide
392:Guide
183:buoys
120:Guide
703:hull
654:and
629:off
342:and
309:off
249:The
242:and
701:âēs
650:in
472:to
377:in
348:fog
253:of
171:TNT
105:âēs
61:of
43:RAR
1059::
950:^
932:^
912:^
876:^
856:^
838:^
812:^
658:,
476:,
422:,
293:,
143:,
123:.
23:.
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