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Navy ELF to Be Scrapped
engywook writes "National Public Radio and The Daily Press of Ashland, Wisconsin (among others, I'm sure) are reporting that the US Navy plans to scrap the Extremely Low Frequency (ELF) system for communication with its fleet of nuclear submarines, both in Wisconsin and Michigan. The report states that the Navy no longer feels that ELF is necessary, and that they will now rely on 12 VLF systems. The system has been in operation since October 1989. The system has been protested nearly the whole time, both as a part of a Weapon of Mass Destruction and as a potential health hazard."
The ELF system was designed so that it didn't have to rely on satellites or even the earth's atmosphere reflecting radio waves. ELF waves travel through the earth; the ELF system would be used in the even of a global nuclear war, so that if all other communications means go down, submarines can still be in contact naval command. A laser would be totally inappropriate for this; it needs line-of-sight to work.
The news article doesn't really have any technical information on ELF, so here's the obligatory Wikipedia article.
Of course, the first haphazard search I tried came up with this.
It would be cool if it didn't suck.
They can't have been the Collins class subs, then. They haven't had the best of times in service with the Australian Navy...
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Apart from human pulse being more in tune of 1/60Hz, the idea that 60Hz is something dangerous to health would force us to scrap a good part of current AC systems.
A quick Google search revealed the following: ZEVS, THE RUSSIAN 82 Hz ELF TRANSMITTER. Located near Murmansk. The article has some nice maps, screenshot of the spectrum, etc.
When we do exercises with foreign nationals, we have to mask our true sound signature, so as not to give away valuable data on HOW quiet we are, exactly what noises we normally make, and how best to detect us. Also, a submarine exercise where nobody can see anyone else isn't very good training - it's just driving around in circles. So sometimes we have to give away our position on purpose to get the show on the road.
That means we have to run all kinds of noisy gear that we normally don't (or only do when we're sure nobody is around) when non-US subs are about.
In addition, we frequently have "prospective" commanding officers play captain-for-a-day during the exercises to get some experience before we let them loose by themselves on a sub where, essentially, they're an absolute ruler.
The interesting thing is, we don't lose EVERY time, or even MOST of the time.
There are currently 29 GPS satellites in orbit, 24 functional and 5 spares to be used as backups. They are in 6 12-hour orbits to ensure that there are at least 4 satellites available from every position on earth at all times.
Basically, in order to locate you in three dimensions, the GPS receiver needs to be able to see four satellites. (It's actually locating you in four dimensions: X, Y, Z, and time).The satellites, however, not being in different times, cannot triangulate on your time, but instead assume that you are in the same time that they are in (A reasonable assumption). In fact, only three satellites are needed to triangulate on your 3-D position, but due to various atmospheric conditions that vary the amount of time for transmission, and therefore vary the distance estimates, a fourth satellite is always used for error checking. With four satellites, you have four combinations of three satellites, with each combination giving you a 3-space estimate. You can then average these four estimates to get a more correct position. The more satellites, the more pieces of information you can apply to the problem, and the more correct your estimate -- which is why seven is often the prefered number for most civilian applications. Even with seven, though, there are errors, so all data collected with GPS units should then be corrected by referencing it to a nearby base station with a known exact location on the earth's surface.
As for the other post that suggests the reason 3 can be used is because the system knows you are on the Earth's surface -- this assumption would be true if, 1) the system made such as assumption, and 2) the Earth's surface were smooth. Since the system locates the position of mountain climbers, forest rangers, cars on roads, and airplanes in the sky, neither assumption can be made.
That would be pretty hard to do. With watch-to-watch pub and crypto turnover, TPI (Two-Person Integrity), and other safeguards, ti would be hard to steal the crypto. Even if you're the WatchSup, you CAN get your own padlock open, but the second person has to do so or comply. After that, the second person would have to turn a blind eye long enough for the trusted spy to somehow copy the strips or cards or sheets.
Even so, once the compromise is discovered, the entire fleet would cease using the crypto, except for maybe a handful of decoys in the compromised area who'd continue feeding disinformation into the system to delay knowledged of the compromise. However, once the genereal oparea is told to cease using it, the compromise effectively is known. Even if the reported compromise is covered by HQ just self-censoring what it sends over the encrypted circuits, an enemy or defector using the crypto cannot use it beyond an predetermined, scheduled time block. Just as newsfeeds expire, so do crypto periods.
While it would be possible to steal crypto for a given period, they physical evidence (hard plastic, clear or dark, in clumps or packages that will be obviously missed if moved or remove), you generally cannot steal it now and use it later, for timeshifting (not exactly like TIVO, et al) would elminate the usefulness. Meaning: Crypto stolen for period 0600-1200 or whatever used AFTER that period simply won't work. They cyphers embedded in the transmission stream would ensure that improperly-embedded responses trigger a compromise alert.
Read some books out there (communications pubs, crypto books, communications security methods, and your imagination. It's not necessary to bribe anyone for information if you can reassemble or combine peripheral evidence. Read and re-read. The process I describe is not in itself super sensitve. The crypto IS. The physical protection of it IS. Stealing it is pointless, except to invite jail time.
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As for knowing where the sub is, subs have OpAreas just like surface ships do. The satellites would signal to as narrow an areas as possible, likely in bursts, over a short duration, and at random intervals so as to deny detection of the boat's locality if a trawler or signal-soaking craft is in the area by chance. Alternatively, the sub can release a trailing wire antena for maybe 2 miles, and collect instructions or messages. In a worst case, they could cut the cable and go deep and quiet in a threatening situation.
I would imagine that remote sensors or torpedo-like vehicles slip from the hull, trail or shadow the boat, and send and receive signals from a non-disclosing distance. It's what IIII would do if I had the valuable boats, the money, and the imagination I have now. We have predtors for ground crews, so why not remote off-board vehicles for expensive subs that might have to sit or hover (to keep sand out of certain cooling intakes) for extended periods, periodically degaussing (or doing other things to/for) their hull signature. A ROV would SIGNIFICANTLY enhance the privacy, security, safety, and stealth of ANY navy's subs, for a smaller price than innumerable anechoic tiling and rubber-mounting deck rafts.
David Syes
-Former Radioman (86-88)
-Armchair Tactical Action Officer before and after my 4-year stint in the USN
-recreational submarine designer (concepts)
-recreational/"otaku" DDG/DD designer (to embarrass the DDG-51 design (both flt I and II)
-aspiring fiction author (relying upon fact and disinformation available in many, many carefully selected texts available publicly)
Previously: "Linux... Toward the Sunrise..." Now: "Linux... Toward the-- No, now, part of Every Sunrise"