NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Dip-meter again
From: Fred Hebard
Date: 2012 Apr 10, 21:11 -0400
From: Fred Hebard
Date: 2012 Apr 10, 21:11 -0400
Alex, No problem. I started this speculating that Soviets used dipmeters more than other navies because they operated more in Arctic waters than other navies. You then mentioned a need for accurate sub navigation for ballistic missile launches, and operation of same in Arctic waters. I mentioned the Transit system, but we established it was not operational prior to 1964, whereas the Polaris subs were operational in 1961. I then cited inertial nav, which you pointed out needs to be corrected for drift, leading us back to cel nav My understanding is that inertial nav on subs had much less drift than on surface ships or planes because subs are not exposed to waves or turbulence. But I have not found any references to this, although the Google book I quoted may have more details. My understanding of cel nav from periscopes is that it is difficult and imprecise. As an alternative to calibrating inertial nav with cel nav, some others have mentioned Loran, etc, but that doesn't have coverage everywhere, as you pointed out. Another alternative might be mapping of underwater features such as mountains, as well as triangulation from sonar beacons. But I still think inertial nav may have been the main trick for the U.S.; it was bragged about in detail in the 70s, when it may have already been rendered obsolete by the Transit system. Fred On Apr 10, 2012, at 6:30 PM, Alexandre E Eremenko wrote: > > Fred, > > I understand that we were discussing different > inertial nav systems, and I think I perfectly understand > your English:-) I only tried to make clear that we were talking of DIFFERENT things. > (If you are talking of a different thing from the thing your interlocutor > is talking about, you do not begin your sentence with "No", > correct?) > > Anyway, let us discuss now inertial nav of a submarine itself. > If I understand correctly, inertial nav alone cannot be accurate > over a long period of time. Because the error accumulates. > > So it is not a substitute for Cel Nav, and can only complement it, > when the boat is under surface and Cel nav is not available. > > In any case, I think that my argument that high accuracy > Cel Nav was necessary for launching a ballistic missile is valid. > And it was indeed necessary in the period after ballistic missiles > appeared, and before sattelite nav became available. > The first ballistic missile launched from a submarine > was in the middle or late 50-s (different sources give different dates). > But they agree that this was a Soviet submarine which launched > SS-11 Scud missile. > > Satellite nav was apparently not available in USSR until they > started to use the de-classified US Transit system in 1967. > Russian book of 1989 (!!) only mentions this satellite system, > but adds that "Soviet Union also has one" without any detail. > Perhaps a secret one. > > In general, Soviet space program was a king of "show business". > They wanted to sow to everyone that they have working ICMB. > In 1960-s I was a child, and I followed the space exploration very closely. The Soviets launched first satellite, then first man, > then first woman, etc. Everything was widely advertised as "world's first's". At the same time, US launched hunderds of satloites which were not advertised. All we knew was that these are "communication satellites" > or just "secret satellites". But they made real use of these satellites:-) > > Sorry for deviating from the list subject. > > Thus the interest to accurate Cel Nav was really brief, especially in > the West. > > Alex. > > On Tue, 10 Apr 2012, Fred Hebard wrote: > >> >> Alex, >> >> The inertial nav I was discussing was for determining the position of the submarine prior to launch, rather than sat nav, as I had suggested earllier. This is clear to me in the text I quoted, but perhaps not as clear to you, being a non-native speaker of English. It also aligns with my memories of the description of the method, in National Geographic or wherever. >> >> >> Fred Hebard >> >> >> >> >> On Apr 10, 2012, at 2:52 PM, Alexandre E Eremenko wrote: >> >>> >>> Fred, >>> >>> I suppose that when speaking of "inertial nav" as a guidance system, >>> they mean the nav of the missile itself, not of the submarine. >>> >>> To use an inertiale nav in the missle one needs the position >>> of the starting point. This is what Sat nav was for. >>> >>> Now we see Shufeldt's report in new light:-) >>> The reaseach was made in 1957-1961 :-) >>> And then classified. >>> Exactly at the time when they developed the Polaris A-1 missile... >>> >>> When Transit became available, they declassified the Shufeldt report. >>> >>> So now we know what "Precision Cel nav" was really for:-) >>> >>> Alex. >>> >>> >>> >>> >>> >>> >>> >> >> >> >> >> >> : http://fer3.com/arc/m2.aspx?i=118918 >> >> >> > > >