I've changed the second expression of the Law of Cosines to this:
Which seems wrong given the diagram:
Keeping in mind that the Law of Cosines looks like:
This item is very confusing and contains quite a lots of errors in the detail (but not in the maths I think). Basically it needs to differentiate between 'sound ranging' used to accurately locate hostile artillery and 'sound location' used to detect aircraft and to direct searchlights at them. While sound is sound whatever its source (well sort of) the problems and solutions are very different. Particularly in its first few decades, modern electronics and uses seem to have changed matters somewhat. Mixing it up with flash-spotting and radar for artillery locating, which also contains errors of fact, doesn't help either. Nfe 09:57, 19 February 2007 (UTC)
I feel that this article is in need of reorganisation to reduce its confusion. At present, it covers a number of related topics which should really be separated into articles of their own. It seems that the original content was to be that known as GSR - Gun Sound Ranging - but it has spread into more general location by sound and, indeed other methods. It may be better to consider an overarching topic "Artillery Location" with subtopics GSR and Flash Spotting, plus links to Artillery Survey, if that exists (and it ought to!). The accoustical detection of aircraft, which was developed in the UK between WW1 and WW2 but effectively dropped with the emergence of radar, is an interesting but separate topic, IMHO. Comments anyone?
--Alister Mitchell 17:54, 26 July 2007 (UTC)
I think 'hostile artillery location might be better. The issue is its far broader than SR, FS and radar - see the artillery entry. To treat it properly it would need to consider all the methods identified in say, various 1920's articles in the RA Journal and 1916 'GHQ Artillery Notes No (3? - would need to check)- Counter Battery Work'. Foremost among these would be the development of air photograph interpretation. However I agree the last section 'Sound Location' needs expanding and moving elsewhere.
Incidentally in the newly referenced item, in the first section, the date of amalgamation of RFA and RGA is a couple of years wrong.
Nfe 03:36, 27 July 2007 (UTC)
Hostile Artillery Location is one thought but it seems clear from all the training materials available from the 20s (at least) that ranging was a major part of the SR Troop's work up to the end of WW2 (again, at least). Your mention of "GHQ Artillery Notes" is particularly interesting to me - is there online access to it, or will I have to have another trip to Woolwich? I agree that the whole Artillery area needs an overview - guidance from those in command would probably be needed. Possibly this would be best done by a group? I don't know yet how that sort of thing works.
BTW,, can you give me a reference for the RFA/RGA amalgamation date? Off the top of my head, I can't remember what my source was - but there was one!
--Alister Mitchell 22:01, 4 August 2007 (UTC)
1924, History of the Royal Regiment of Artillery - Between the Wars 1919-39, Maj Gen BP Hughes,1992.
GHQ Artillery Notes No 3 - Counter-battery work. Feb 1917, new edn Feb 1918. You won't find them (or others in the series)at Woolwich, which is why they aren't referenced in most works! They were also 'Confidential' and this may be why they weren't referenced in the various articles in RAJ in the 1920s (eg those by Brooke, Broad) or in the article in the Cdn Defence Quarterly by McNaughton in that period. However, they are held by the IWM.
Various other relevant pamphlets in AWM include: Co-operation of Sound Ranging Sections and Observation Groups with Artillery (SS 199 Nov 1917 'Issued by the General Staff') this was replaced in May 1918 by Ranging with Observation by the Field Survey Company.
Incidentally I note that you don't reference Peter Chasseud's 'Artillery's Astrologers'.
The WW2 DUAIs are listed on the sources page in http://members.tripod.com/~nigelef/index.htm . About half of them concern SR or FS, interestingly there no mention of the awesome plotter in the 1933 Instruments HB, I don't think this device was used. In WW2 the comparator was the key instrument for ranging (ie directing own guns against HBs located by SR). In both WW1 and WW2 'ranging' in mainstream arty use refers to what is now (since 1965) called 'adjustment'. It's a bit confusing that 'ranging' in sound ranging has a slightly different meaning and includes target acquisition (locating) of HBs.
Post WW2 the plotting boards had a steel surface and used magnetic 'weights' on the ends of the strings. These were replaced by HP calculators used for survey calcs, see the Maps & Survey page of the above site. For more modern pubs the Baddeley Library at Larkhill is a better bet than Woolwich. Nfe 06:35, 5 August 2007 (UTC)
Diagram has been hijacked
As of 15 December 2010, the diagram for sound ranging has been hijacked/overwritten by an unrelated diagram from a different wiki. If you look at the [revision history] for the diagram, it was replaced on 29 November 2010 by a totally unrelated diagram (which appears to have something to do with acoustic levitation in a wikibook). Suggest that the file be moved to something more clearly related to this article (to prevent such confusion in the future), and restore it to the geometric diagram .