[QUOTE=DrFidelius]
Just how much information do you think a torpedo needs? A firing solution is generated before the fish is launched, and would only need a little tweaking to adapt to evasive actions of the target.
Big boats do not change their course and speed easily or quickly.
[/QUOTE]
Updated telemetry at least on the order of 1 Hz; boats may not change vectors quickly, but the game between a submarine and a conventional torpedo is closer to a game of chess than a dogfight; torpedoes are often fired at significant range (too close and the boat being attacked will just fire back, both boats will cut control wires and launch countermeasures, and the odds of interception are low) and a boat can well evade by going beyond torpedo range, ducking under a sonar-reflecting thermocline, getting lost in surface scatter, et cetera. (Those scenes you see in the film adaptation of The Hunt For Red October with Ramius overrunning in a preplotted course and later playing chicken with another sub are pure nonsense; no sub commander who wasn’t terminally suicidal would ever attempt such a thing.)
Conventional torpedoes are controlled via control wires that are fed out with the fish, and modern torpedoes have internal sonar and automated guidance and tracking systems that permit the fish to go solo when the wires are cut; one technique for driving away an attacking sub is to launch a fish without lines and then turn and run, forcing the opponent to do the same.
The Soviets (now Russian Navy) do have a supercavitating torpedo (basically a torp with a small solid rocket motor on the tip that creates and sustains a drag-reducing bubble around the fish) which permits it to go at extraordinary speeds (estimated in excess of 200nmh–conventional prop-driven torps go at about 40-45 nmh, and modern prop-less torpedos can run at about 60 nmh, faster than even the vaunted Soviet Navy Alfa “interceptor” submarine). The original supercavs (‘Shkval’) were just straight-line fish with no maneuvering capability; they’re held off of the surface of the bubble by a set of rotating fins, essentially dancing on the water. (They were designed to carry nuclear depth charges to be detonated within a carrier group, so fine maneuvering capability was unneeded.) Newer ones are alleged to be able to effect maneuvers and even rapid turns without collapsing the bubble; obviously, at these speeds the control wires would introduce substantial drag and thus be undesirable; a low frequency radio controlled system (using high compression telemetry) would be necessary to control this; the fish obviously couldn’t self-direct using on-board sonar for obvious reasons. Other nations are also work on supercavitating torpedoes and even (supposedly) submarine torpedo-launched cruise missiles which pop up in littoral zones and effect a NOE flight course, making them virtually undetectable and unstoppable except by “look down/shoot down” defense. There is nothing in the US arsenal that does this, but I have to believe that the Navy has contractors working on this frantically in some kind of black program.
Radio doesn’t transmit very effectively underwater, as discussed above, but an satelllite-based intense laser of the right frequency to pass through sea water could theoretically penetrate hundreds of feet, assuming you have a clear surface and adaptive optics to compensate for atmospheric turbulence and variable refraction from changes in salinity due to depth. It might be possible to control a fish by communicating from boat or remote station to satellite to torpedo.
Lamarr’s scheme was essentially a variation of frequency division multiplexing, which is easy to implement today but virtually impossible to do with the electromechanical systems of the day in a practical manner. It is highly suspected that Lamarr did not develop this entirely herself (or rather she and composer George Antheil, her co-awardee of the American patent), but rather ‘acquired’ it from her German ex-husband and allowed to patent it to support the war effort and avoid patent conflict issues.
Stranger
