Talk:Sonar/Archives/2013

Active Sonar

This section asks for information on sources/references. The best source of information on this and most aspects of sonar and underwater acoustics is Urick's book quoted in the bibliography. How is this best inserted into the article? Denstans (talk) 15:27, 10 January 2010 (UTC)

Anti-Submarine Warfare

This section is a mess. It doesn't make much sense grammatically, but I lack the knowledge on the subject to correct it without altering data that may or may not be accurate. Anyone? —Preceding unsigned comment added by 69.3.63.244 (talk) 04:33, 30 June 2009 (UTC) Sonar is pretty epic :P

Fisheries Echosounder Manufacturers

There are many, many fisheries echosounder manufacturers, HTI is not one. Reference removed.

ASDIC

The article contradicts itself as to what "ASDIC" means. Anyone know what it is supposed to stand for, or is it like BNC? Thanx 68.39.174.150 22:59, 26 May 2005 (UTC)

The article's defintiions are accurate. The article does not contradict itself - it accurately conveys the two alternative forms seen - both terms are frequently encountered and reported as alternates in the same reference.

For ASDIC see: http://uboat.net/allies/technical/asdic.htm

It's unclear whether ASDIC was in regular use in WWI. was it? 92.3.163.80 (talk) 22:44, 7 December 2009 (UTC)

Target Motion Analysis

TMA requires that the submarine to change it course in order to exclude incorrect solutions of the target's location and trajectory.

File:TMA.gif

Suppose the blue circle is your own ship, and the blue line indicates the course and speed. Yellow lines indicate the bearing of the target over time. There exists two solutions for the target. If the course of the target is left of the bearing lines, then the intersection of the bearing lines represents the maximum range of the target from ownship. If the course of the target is on the right of the bearing lines, then the intersection represents the minimum range to the target. Suppose ownship basically did a U turn, the next few bearing lines will help determine the location of the target. I know this isn't the best explanation, but one could look up guides on the 688(i) simulation games to have a better explanation of TMA

Actually, TMA does not require that the submarine change its' course for an accurate solution. There are a few different ways to lower the +/- of the bearing and range solution. Changing own ships' course can aid in the solution; frequency/bearing rate ananlysis; finally, the best of all worlds - more than one sonar platform (ship, air, submarine, directional sonobuoy) in contact.

Bogus return power levels

The article give "hypothetical" examples of 20W emitted power and 4W returned power. These figures look extremely suspicious. Radar usually emits kilowatts of power and listens for milliwatts or microwatts of power reflected from targets. I'd expect similar order-of-magnitude differences for sonar. --Quicksilver^{T @} 20:41, 5 December 2005 (UTC)

Yeah, the maths was rubbish. I've tried to sort it out. Greglocock 10:49, 28 December 2006 (UTC)

Target Motion Analysis

I am not an expert on SONAR however, if my understanding is correct, the Towed Array SONAR (TAS) gives two simultaneous readings for bearing, one of which is incorrect or 'ambiguous bearing'. In order to identify the true bearing of the target, the submarine should change its course (even by a few degrees). There is no mention of the ambiguous bearing in the article and may be that's what has caused the confusion of changing course and TMA. StarChaser 11:18, 11 January 2007 (UTC)Ali A

You are correct. Towed array sonars actually return a "theoretical cone" where the target could be. However, since the target is not above the surface, or below the ocean, it is often referred to as the "ambiguous beam". For example the target could + or - 45 degrees from forward motion. Many times the logic of the operation rules out one side or the other (i.e. port security), but sometimes you have to move the ship. If one side has an unreasonable amount of motion in the target, you can presume that it is on the other side. However TMA analysis is often much more complex than trying to calculate the ambiguous beam. TMA may help you resolve false alarms. The target could be doing evasive maneuvers (such as sprint and drift). Sometimes the ship tows more than one towed array, so that it can resolve the ambigous beam immediately. Pacomartin (talk) 16:18, 4 January 2009 (UTC)

Alexander Behm?

German Wikipedia says: Alexander Behm erhielt am 22. Juli 1913 das Reichspatent Nr. 282009 für die Erfindung des Echolots

That means something like: Alexander Behm got in 1913 the patent for Sonar for inventing it. —Preceding unsigned comment added by Droschmisch (talk • contribs) 21:55, 16 June 2006 (UTC)

earl d. hernan

Sonar as a Weapon

I remember reading a few years ago about a proposal to use a large ship based sonar array as a CIWS system against incoming torpedos; using phased array technology to hit them with a focused over-pressure wave. I forget whether the intention was to simply blind the seaker-head or (IIRC) to actually damage it. Does anyone know of a good reference source so this can be added to the page? ANTIcarrot 12:29, 25 April 2007 (UTC)

Sounds like a fantasy to me. I imagine the proposer got a few mill to investigate it from the DoD! Greglocock 23:55, 25 April 2007 (UTC)

Initially it sounds like a fantasy to me also. Even if you could theoretically obliterate the guidance system of a torpedo, it is moving at 40 knots, and you would require an unbelievable course change to prevent damage. However, modern torpedos don't usually hit the ship, but they go under the keel, and are designed to blow up underneath the ship without contact. They carry an explosive with a lot of aluminum which blows a giant bubble in the water. The collapse of the buble cracks the keel of the ship doing a lot more damage than you could with simple contact explosion. Ships expect to be supported by water, and are very fragile if they are suddenly in air. It might be theoretically possible to disable this control mechanism with enough acoustic energy. You wouldn't have to change the course of the torpedo. It's too bad you don't have a reference. Pacomartin (talk) 16:33, 4 January 2009 (UTC)

Acoustic Emission?

"Acoustic emission measurements can also be made for crack detection." I don't get what acoustic emission from cracks is doing here. How does that involve ranging or location? Just because it uses sound doesn't mean it's sonar. I'm going to chop it out, and whoever stuck it in there can justify it here if they want to put it back in. Tarchon 18:07, 5 June 2007 (UTC)

Let me clarify this since I just realized how someone's going to jump on it - AE is primarily used as a crack detection techique, not a mapping technique. In _some_ implementations of AE multiple receivers are used to infer the location of the crack in the solid via time of flight analysis. You could perhaps consider this to be some kind of "passive sonar," but under such a broad definition of sonar, you would have to consider every use of sound to infer location as some kind of sonar. Like when you hear a sound and know which direction it's coming from, would that generally be considered sonar? I don't think so, and AE location is only sonar in that extremely broad sense. I guess part of the problem is that in marine terminology especially the term "passive sonar" is often loosely used as kind of a dump term for virtually any kind of sound analysis, but I think we should be a little more restrictive. I think I'm going to move the AE thing down to the passive section and make it more tentative. Tarchon 20:12, 5 June 2007 (UTC) (originally 19:12, 5 June 2007 UTC)

Actually, I'm just going to leave it deleted - not being aquatic is the critical point for exclusion. Otherwise, this article could include everything from medical ultrasound to lunar seismology. Tarchon 20:12, 5 June 2007 (UTC)

Sonar not just sound propagation

At the start of the page it says that sonar is about underwater sound propagation. It is more that that and should say that it is about underwater sound applications.Adresia 12:11, 24 June 2007 (UTC)

Who is Lewis Nixon?

The work of Richardson, Fessenden and Behm is well documented, but I have never come across the name Lewis Nixon before. Please supply a proper reference to his work (not an internet link) Thunderbird2 15:04, 1 July 2007 (UTC)

I do not see what is wrong with the references provided. If you google "Lewis Nixon sonar", you will get dozens of references to his invention. Lewis Nixon was a prominent shipbuilder of the time and was instrumental in several major ships. --rogerd 19:12, 1 July 2007 (UTC)

The problem with the internet references is that they are not verifiable. I am interested to learn more about this man, but there are no citations in his Wikipedia biography to check out. If he really did invent sonar, he should be acknowledged, but I see no hard evidence for this assertion. How did his sonar work? What materials did he use? Why did it take the combined efforts of two European physicists (Paul Langevin and A B Wood) to repeat something that had been done more than 10 years before in the USA? etc. Please tell us more Thunderbird2 19:30, 1 July 2007 (UTC)

I return to this point 4 weeks on. I still know almost nothing about how Nixon's "sonar" is supposed to have worked, and whether he actually made something or whether it was just an idea that he patented (or didn't patent?). According to wikipedia's guidelines on verifiability, a "Surprising or apparently important" claim that is "not widely known" requires "multiple high quality reliable sources". Last time I checked, the intute link [1] returned a "page not found" error. It seems to me that this claim is an important one that fails the test for multiple reliable sources. Therefore it should be removed from both sonar and Lewis Nixon. Comments anyone? Thunderbird2 14:15, 29 July 2007 (UTC)

I can't find any real sources mentioning Lewis Nixon's invention of sonar, so I'm going to remove the claim from his page and also from here. TomTheHand 13:23, 13 August 2007 (UTC)

I have removed the claim from this one also, but I'm not sure how to deal with wikibooks. Thunderbird2 15:25, 13 August 2007 (UTC)

I just deleted the two sentences that were lifted from about.com. We'll see if they pop back up. TomTheHand 15:32, 13 August 2007 (UTC)

It appears that Lewis Nixon was a shipbuilder who, in a paper on MTBs, included a single sentence proposing the use of underwater sound for the detection of submarines. He can hardly be described as inventing sonar. Unfortunately I no longer have a reference to the original paper but "Hunters in the Shallows" by Curtis Nelson makes reference to it. Adresia (talk) 13:01, 9 January 2009 (UTC)

Multibeam echosounders

There is a serious dearth of information on multibeam echosounders on wikipedia. The MBES article itself is very small, while the topic only had a passing mention (and until now no links) in both the sonar and echo sounding articles.

I've put in the links, and will have a go later at sorting out the three articles. (Probably best to sort out the multibeam echosounders article first, so it will be easier to work out how much they should be described in Sonar and Echo Sounding). Wardog 16:16, 23 September 2007 (UTC)

One of the external links to noaa.gov is dead, but they do have an article on MBES and PDBS as well, which are both used for bathymetry. Under the uses: topo only references SSS, which is useless for bathy. At the moment these links at noaa are working: http://www.nauticalcharts.noaa.gov/hsd/SSS.html http://www.nauticalcharts.noaa.gov/csdl/PDBS.html http://www.nauticalcharts.noaa.gov/hsd/multibeam.html — Preceding unsigned comment added by 202.20.20.202 (talk) 02:43, 12 December 2011 (UTC)

wikipedia

wikipedia is crap and needs to be edited by professionals instead of people who don't know what they're talking about it. But the free knowledge is definitely a great idea. —Preceding unsigned comment added by 128.200.69.133 (talk) 22:12, 19 November 2007 (UTC)

Something is Wrong

"In 1916, under the British Board of Invention and Research, Canadian physicist Robert Boyle …" Robert Boyle?! That is complete nonsense. Would someone who knows something about Sonar please rectify this. 128.189.151.122 (talk) 19:01, 17 December 2007 (UTC)

Apparently it's not nonsense, but of course it's not that Robert Boyle. I've added the middle name to the link, making it a redlink (for future expansion). -- Coneslayer (talk) 20:41, 17 December 2007 (UTC)

The book Shield of Empire says that scientists in France were developing an active system, no date given. And also the Lancashire Anti-Submarine Committee in the Mersey and Menai Straits. These areas were not ideal so the work was transferred to the Clyde, initially Ardrossan. In the meantime the Clyde Anti-Submarine Committee had been set up using scientists from Glasgow University, it took over the Shandon Hydropathic Hotel on the Gareloch. Some scientists were transferred from Aberdour. A few ships were fitted out at Parkeston Quay in the middle of 1918 but they were too late to have any effect on the war. —Preceding unsigned comment added by Jmb (talk • contribs) 14:24, 25 January 2008 (UTC)

The French work (by Langevin and Chilowski) is already mentioned in the article. Thunderbird2 (talk) 15:18, 25 January 2008 (UTC)

I was just adding a bit more detail about the UK work in case wanted, I thought I had better include the reference to France of someone would get upset! --jmb (talk) 16:58, 25 January 2008 (UTC)

I see. The book you mention Shield of Empire is unfamiliar to me, but I wonder whether it may shed some light on a controversy that arose here some months ago. Does the book mention Lewis Nixon anywhere? Thanks Thunderbird2 (talk) 17:30, 25 January 2008 (UTC)

I can help here !!! In 1917 the US Navy acquired DR. J. Warren Horton's services for the first time. On leave from Bell Labs, he served the Government as a technical expert, first at the experimental station at Nahant, Mass., and later at US Naval Headquarters, in London, England. At Nahant he applied the newly developed vacuum tube-then associated with the formative stages of the field of applied science now known as electronics-to the detection of underwater signals. As a result, the carbon button microphone, which had been used in earlier detection equipment, was replaced be the precursor of the modern hydrophone. Also during this period (WW I) he experimented with methods for towing detection. This was due to the increased sensitivity of his device. The principles are still used in modern towed sonar systems. To meet the defense needs of Great Briton, he was sent to England to install in the Irish Sea bottom-mounted hydrophones connected to a shore listening post by submarine cable. While this equipment was being loaded on the cable-laying vessel, the War ended an Dr. Horton returned home, after celebrating the Armistice at the Hotel Adelphi in Liverpool. During WW II he continued his participation in the development of sonar systems for the detection of submarins, mines, and torpedoes. He published FUNDAMENTALS OF SONAR, in 1957 as Chief Research Consultant at the US Navy Underwater Sound Laboratory. This position he held until 1959 when he became Technical Director, a position he held until mandatory retirement in 1963.(from DR. Horton,s auto-biographical sketch and US dept of Navy Undersea warfare center)Posted by C. Benjamin Hortonbeny (talk) 21:08, 11 February 2009 (UTC)

Sonobouy Development Reference

The point about sonobouys being developed by the British in 1944 is a bit misleading, as the US was also developing sonobouys at the same time (AN/CRT-1). Edit needed?Wdonzelli (talk) 04:19, 2 January 2008 (UTC)

Mathematical sonar modelling

This is a bit OT, but I'm having a hard time navigating (!) sonar research papers, and I'm on the hunt for a state space sonar model (x'=Ax+Gw; y=Cx+v). Does anyone know if any current research is done on sonar simulation models and sonar estimates? —Preceding unsigned comment added by 130.236.245.182 (talk) 10:55, 19 February 2008 (UTC)

In thirty years

of naval service, and two degrees of electrical engineering I've never heard the Jargon here:

“ Active sonar uses a sound transmitter and a receiver. When the two are in the same place it is monostatic operation. When the transmitter and receiver are separated it is bistatic operation. When more transmitters (or more receivers) are used, again spatially separated, it is multistatic operation. Most sonars are used monostatically with the same array often being used for transmission and reception, though when the platform is moving it may be necessary to consider a single transmitter/receiver as being operated bistatically. Active sonobuoy fields may be operated multistatically. ”

1. How pray tell is a naval vessel going to move fast enough for the condition: though when the platform is moving it may be necessary to consider a single transmitter/receiver as being operated bistatically. I presume you are all aware sonar isn't much use outside of naval platforms... sheesh!
2. Christ on a crutch... this isn't a graduate course text book. Our job is to present basic and elementary information 'first and foremost', not graduate level concepts that totally obfuscate the topic's elementary information! The mission is to educate... not look smart to your peers! Put those things in BELOW--if at all -- way down, but write per WP:NOT PAPERS forsooth. // FrankB 20:52, 29 July 2008 (UTC)

I agree with the proceeding that a fast moving ship is minor issue and should be excluded. I changed the alternative sound sources to a more realistic list.Pacomartin (talk) 16:49, 4 January 2009 (UTC)

I agree. However, on that note I looked up this article attempting to get some idea of the distances active sonar was effective. Specifically for a question about WWII, but it would be nice if someone could supply a time table of "probably correct" effective distances.Aaaronsmith (talk) 21:35, 20 February 2009 (UTC)

Marine Mammals and Sonar

Doesn't seem to be much discussion about this section. Possibly it should be moved to its own topic. I added some paragraphs that I thought would generate some interest, but nothing.Pacomartin (talk) 16:38, 4 January 2009 (UTC)

sonar in air

No airial sonar systems are mentioned; only underwater sonar —Preceding unsigned comment added by 81.246.171.68 (talk) 08:33, 24 March 2009 (UTC)

sonar variations

I hear there's a different type of sonar if a submarine is pinging for range to fire torpedoes at, something that upon using would constitute an act of war. I believed the term coined was "attacker sonar" and it is said it is very different from other sonar sounds used. Any info on this? Murakumo-Elite (talk) 00:38, 4 June 2009 (UTC)

Er, what? A wise submarine commander would not be 'pinging' as that is an invite to get a torpedo (or other anti-sub weapon) up his...'baffles'. The whole idea appears to be, stay as quiet as possible and listen ('passive sonar'). Launch a torp. in the right direction, based on your listening and let that ping when it is close enough.
I may well be wrong, but I have never heard of 'attack' sonar. You may be thinking of radar, where apparently there are surveillance (detection) and targeting/attack radars with different characteristics that can be used to tell them apart. Putting a targeting radar on an armed US ship/aircraft would be very stupid. If not an act of war at least a very aggressive(& stupid) action. I believe that US pilots have shot down fighter planes(Libyan?) simply for trying to get on their tail. --220.101.28.25 (talk) 18:37, 1 December 2009 (UTC)

Workover Needed

I don't care enough (nor am I knowledgeable enough) to give this article a once-over, but somebody really needs to run through it and add in-line citations and remove some of the inaccuracies (I just deleted a line about missile subs not having Active Sonar, which is just nuts, and not even borne out by other articles that link from this one). Orvak Bane (talk) 03:25, 8 September 2009 (UTC)

This article states: "In World War II, the Americans used the term SONAR for their systems, coined as the equivalent of RADAR. RADAR was considered very glamorous and effective, and they wanted to cash in on the name." What a load. Jmdeur (talk) 03:44, 20 October 2009 (UTC)

US and Britain or France and Britain?

The article includes the claim "By 1918, both the US and Britain had built active systems". The first active sonar was developed (around that time) in France, with Britain following shortly after. I see no evidence for a similar capability in the USA at that time. I propose changing it to "By 1918, both France and Britain had built active systems" Dondervogel 2 (talk) 16:08, 4 May 2010 (UTC)

Well done - people know nothing - which is why wikipedia is dying. However *does jazz hands* "No link?!?!?!?! IT CANT BE TRUE". I reply "Im reading a book that has a million citations and was properly researched". But guess what I found: http://inventors.about.com/od/sstartinventions/a/sonar_history.htm — Preceding unsigned comment added by Quickstick4 (talk • contribs) 21:33, 18 April 2012 (UTC)

lol (I suspect the nonsense about Lewis Nixon originated from Wikipedia itself - fortunately long since removed). 16:10, 20 April 2012 (UTC) — Preceding unsigned comment added by Dondervogel 2 (talk • contribs)

Edit request on 9 December 2011

SOANR DAY is 25th Sept. as it is the most crucial day in the SONAR day.

Rathoreabhimanyu2007 (talk) 16:58, 9 December 2011 (UTC)

Do you have a source for this? --Jnorton7558 (talk) 22:10, 9 December 2011 (UTC)

ASDIC Name

Okay, so I understand that ASDIC does not stand for "Allied Submarine Detection Investigation Committee", but I am confused about where the ASD in 'ASD'ics and 'ASD'ivite (this is the way the article currently reads) come from. After a little thought, I came to the conclusion that the ASD stands for the Anti-Submarine Division mentioned at the beginning of the paragraph. If the intent was to only make the connection from Anti-Submarine Division to ASD only through implication, it is not enough - it needs to be more directly stated.

Also, one further thought, could the confusion revolving around the etymology of ASDIC stem partially from the fact that the ASD in 'ASD'ics came from Anti-Submarine Division? (If I am correct, that is) I mean, if one part of the name truly did come from the title of government body, maybe people (i.e. the Admiralty) just extrapolated "Allied Submarine Detection Investigation Committee" from the acronym. What I'm saying is essentially that maybe the 1939 definition wasn't entirely wrong - maybe the Admiralty knew that ADSIC was [at least partially] based on a name for a group, they just didn't know what. (Careful though, this is WP:SYNTH on my part - it is based solely on my own educated guess. I mention it because maybe there is a citation to prove this out there somewhere.)

I did notice the discussion about ASDIC above, but thought that if I included it in that section, it would go unnoticed. --Noha307 (talk) 19:18, 28 June 2012 (UTC)

I've just gone through my copy of the Technical History and Index which concerns this: Volume 1, No. 7, "The Anti-Submarine Division of the Naval Staff. December 1916—November 1918." The relevant section is titled "Asdics", and throughout the term is never capitalised. Unfortunately no mention is made of the origin of the name. —Simon Harley (Talk | Library). 20:20, 28 June 2012 (UTC)

A good first hand reference is an autobiographical account of the history of sonar by A B Wood, who worked with Robert Boyle during WWI. I will look it up. Dondervogel 2 (talk) 17:22, 3 July 2012 (UTC)