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#201
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On Sun, 21 Dec 2003 19:24:21 GMT, Charles Gray wrote:
Phil misses the point, that most of the third world jsut doesn't have the capabilities he's looking for. Even nations like China are still importing weapons systems, not because they're stupid or mud huts, but because the infrastructure to develop systems like this takes a long, LONG time to develop. Yes, and China makes a lot of its own weapons. As do countries like India, or Iran, or South Africa, or Brazil. -- "It's easier to find people online who openly support the KKK than people who openly support the RIAA" -- comment on Wikipedia (Email: , but first subtract 275 and reverse the last two letters). |
#202
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On Sun, 21 Dec 2003 19:38:09 GMT, Charles Gray wrote:
And Phil, that's another problem with your ideas-- they assume a government that is reasonably non-corrupt, I would put it differently "... reasonably competent", but i suspect we're talking about the same thing. and I can tell you from expereicne that most 3rd world nations are run in a fashion that would make Boss Tweed blanch. If a country already has a proven capability to design and build aircraft, it can probably build its own cruise missiles. -- "It's easier to find people online who openly support the KKK than people who openly support the RIAA" -- comment on Wikipedia (Email: , but first subtract 275 and reverse the last two letters). |
#203
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On Sun, 21 Dec 2003 23:21:49 GMT, Fred J. McCall wrote:
(phil hunt) wrote: ![]() :developing algorithms is what programmers do. No, IMPLEMENTING algorithms is what programmers do (and often without understanding of what they are implementing). DEVELOPING algorithms is what software and systems engineers do. "software engineer" and "programmer" are different words for the same job. -- "It's easier to find people online who openly support the KKK than people who openly support the RIAA" -- comment on Wikipedia (Email: , but first subtract 275 and reverse the last two letters). |
#204
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On Sun, 21 Dec 2003 23:41:35 GMT, Fred J. McCall
:co-ordination = radio In which case we're going to KNOW when you're spooling up to shoot and you'll be dead before everybody gets rolled out and ready. Hasve you never heard of encryption, or are you trolling? -- "It's easier to find people online who openly support the KKK than people who openly support the RIAA" -- comment on Wikipedia (Email: , but first subtract 275 and reverse the last two letters). |
#205
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On Sun, 21 Dec 2003 23:55:08 GMT, Fred J. McCall wrote:
(phil hunt) wrote: :On Fri, 19 Dec 2003 13:43:49 -0500, Ray Drouillard wrote: : :Also, since it's not encrypted, it can be spoofed using a local :transmitter : :That doesn't logically follow; it's possible to make non-encrypted :data that can't be faked, you just use a digital signature. But the 'digital signature' is really just another encryption algorithm, typically more easily faked or broken than full encryption. *plonk* -- "It's easier to find people online who openly support the KKK than people who openly support the RIAA" -- comment on Wikipedia (Email: , but first subtract 275 and reverse the last two letters). |
#206
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phil hunt wrote:
"software engineer" and "programmer" are different words for the same job. Although he seems to be making a hard-and-fast distinction which is not universally made or uniformly recognized by certain terminology, surely you would recognize that there is a difference between higher level design considerations and low-level implementation tasks. On small projects, especially personal or collaborative open source ones, they'll be done by the same person(s) and probably not explicitly distinguished in a task list (concrete or hypothetical), but on large projects the distinction becomes more important. Someone with the title Senior Computer Scientist is probably going to be doing a lot more design the gruntwork, and the reverse is true of someone with the title Member of Technical Staff. -- __ Erik Max Francis && && http://www.alcyone.com/max/ / \ San Jose, CA, USA && 37 20 N 121 53 W && &tSftDotIotE \__/ He who laughs has not yet heard the bad news. -- Bertolt Brecht |
#208
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phil hunt wrote:
George William Herbert wrote: I've done several iterations of this problem, though not with systems that went to full scale development or production. I believe that for suitably moderated operational requirements, the problem can be much simpler than I believe Derek thinks it is. I belive that Phil is grossly underestimating the real requirements, even for those suitably moderated operational requirements. Which requirements am I underestimating? (Bear in mind I'm considering missiles for several different roles). Let me give you an example... assume that you need a certain pixel width of an object to successfully identify it (say, 10 pixels across) with a certain contrast ratio. You also have certain limitations on the maneuverability of the airframe this is all one. It can't pull more than a certain number of G's etc. To successfully design the homing mechanism, you need to assess the distance and light or background noise conditions of the frequencies you're looking at (visual, IIR, whatever) and the magnification of the imaging system and its optical resolution. You need to have a wide enough field of view that you can see the targets as you fly along searching, but not so wide that you won't be able to discriminate a target until it's so close that maneuvering to hit it becomes a serious problem. You need to assess the impact on the sensor and field of view of the background coloration across the target areas, etc. With a much simpler system, laser spot homing, I spent some months working out that nested set of problems. Taking one shortcut made the weapon not lock on if the ballistic miss trajectory was too far off. Taking another meant that it typically locked on early in a portion of its flight that led to it flying out of control as it lost energy trying to track the laser spot as it flew out. It would scrub too much forwards velocity off early and then start to come down too short of the target and stall out trying to correct for that. Bigger lifting surfaces would solve that but cause other problems for weapon packaging. The final solution was to modify the trajectory limitations, with the more aggressive sensor system. Which scrubbed a bit off the maximum range (could still reach the old range, but if your aim was off too much in the initial firing it would just out and out miss short). You actually have to sit down, design a notional design, put a notional sensor on it, figure out what the parameters are, and simulate it for a while to see what the gotchas are. That requires models of the sensor, guidance, optics or transmitter, target behaviour, aerodynamics, and trajectory / movement dynamics of the weapon. Even getting a rough first pass of that to tell you what the roughly right answers are is nontrivial, can easily be months of work, and requires experience across a very wide range of diciplines (or a keen ability to figure out what you don't know and find it via research). But few of those have progressed to production. The new Marines/Navy Spike missile is one exception, This is the Israeli ATGM, isn't it? No, there are two missiles named Spike, and I'm referring to the US Navy / China Lake one. http://www.nawcwpns.navy.mil/~pao/pg...es/SpikeND.htm -george william herbert |
#209
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In article mail-0E43D5.00500922122003@localhost,
Michael Ash wrote: North Korea, on the other hand, has enough artillery on the border to completely level Seoul within a few hours, from what I understand. That alone is enough to stop any plans for an invasion. In a way, it's even worse than the nuclear problem. Unlike a nuke and its delivery system, there's no possible way to take out mumble-thousand pieces of artillery before the deed has been done. Kinda makes you wonder how well they can coordinate those artillery pieces... they can't even feed their troops. Out of the tens of thousands of cannons sitting on the north side of the border, anyone want to bet that no more than a couple of hundred actually get to fire? Especially with a few dozen MLRS launchers and a couple of hundred attack aircraft cranking out a few million submunitions across their firing positions... while reducing their command centers to smoking holes in the ground and jamming communications. For reference, look at the "massive" weapons infrastructure in Iraq, and how they never managed to get more than a few percent of them into play. And Iraq was in relatively good shape compared to what Korea's going through right now. -- cirby at cfl.rr.com Remember: Objects in rearview mirror may be hallucinations. Slam on brakes accordingly. |
#210
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