| From: | acgetchell@*******.edu (Adam Getchell) |
|---|---|
| Subject: | Re: Naval units |
| Date: | Fri, 31 May 1996 12:16:32 -0700 |
>range?
"Seeing Underwater with Background Noise" is in the February 1996
_Scientific American_ (pp. 87-90). The operating frequency band is 5-50
kHz, within the range of breaking waves (which provides much of the ambient
noise). Interestingly, some frequencies are strongly reflected or absorbed,
which can be interpreted as acoustic "color" and used to translate into
false-color images.
The experimental setup used an array of 128 hydrophones to generate that
number of pixels. As the pixels increase the resolution increases (90,000
would be ideal - one could see reflections of certain acoustic wavelengths
off a surface and thereby determine its texture). The current system is
able to distinguish moving killer whales, plastic floats, titanium spheres,
and PVC oildrums filled with sand and foam. Furthermore, this can be
distinguished even on the seafloor. A final bonus: image clarity and
contrast, amazingly enough, _increases_ with distance from the sensor.
The article did not include enough data to determine range and efficacy at
speed. Looks promising, however (they had no trouble with extremely mobile
killer whales as targets, so dopplering doesn't seem to affect things).
>Don't feel bad, this is my job :)
So I noticed. ;-)
>>True. With hovercraft, though, the larger the platform the more clearance.
>>I was thinking in the 100-ton range with a sensor suite, CIWS, spoofing
>>gear, and torpedoes. Definitely include sonobuoys, and if it's cheap
>>enough, a towed-array. Thoughts?
>
>Won't get a tail on the hovercraft, but this is a localisation/attack
>platform replacing a helicopter. The problem is you lose the helo's
>ability to do jumping-jack surface searches, for instance, and the
>hovercraft is a lot more vulnerable to fast-attack craft than a helo.
>Tradeoffs, tradeoffs... Interesting idea, though. Makes a LPH an
>effective ASW 'carrier' instead of an amphibious transport.
Hmmm. I was wondering if a future ASW frigate or destroyer might carry a
pair of skiffs in addition to its helos. I suppose this skiff could always
fire torpedoes at incoming enemy fast attacks; unless they're
hydrofoil/hovers, in which case perhaps dual purpose airburst SAMs.
That brings the equipment up to sonobuoys, dipping sonar, SSMs with
torpedoes, a CIWS, perhaps a battery of SAMs. Still doable in the 100 ton
range?
Yeah, an LHA with a dozen or so and helos might be pretty nasty at the ASW
game. Rebirth of the ASW carrier? (Which the Invincible was supposedly).
>More in the 35-45kton range. The problem with Ark Royal is that she'll
>be the last to retire, so the replacements will risk overlapping a name.
>Furious is a honourable carrier name (she was one of the RN's first, a
>conversion of one of Fisher's Follies) as are Glorious and Eagle. More
>Charles de Gaulle than Nimitz, though conventionally powered.
Airwing?
>>I'm also sure the renewed IJN would _not_ name their carriers Sokaku,
>>Zuihu, Ashikaga, etc. ;-)
>
>Oh, I don't know, they brought back _Kongo_... :)
Now I have to get _Proceedings_ for the annual "Fleets of the world" issue.
I wasn't aware the Japanese Maritime Self-Defense Force had carriers...;-(
>Paul J. Adam paul@********.demon.co.uk
=================================================================
Adam Getchell
acgetchell@*******.edu
http://www.engr.ucdavis.edu/~acgetche/
=================================================================
"Invincibility is in oneself, vulnerability in the opponent."
-- Sun Tzu
