Posted by: Steve Walmsley
« on: April 24, 2008, 08:15:40 AM »Quote from: "Michael Sandy"
How is missile leakage handled?
If there are 5 missiles incoming, and 10 point defense shots, in a real world situation you would have 2 point defense shots assigned per target. The less accurate your point defense, the more leaks you get.
For example, 20 missiles vs 40 point defense with 50% kill chance means each missile has a 75% chance of being killed, resulting in 5 leaks. Unless you have multiple point defense phases.
If you have 20 missiles vs 100 point defense with 20% kill chance, you have a leak chance of .8^5 or about 32% leak, so 6 or 7 missiles would leak.
For area point defense, getting a lot of shots that thin the wave before the final impact is more important. But when you are trying to kill all the missiles, for example protecting a planet from bombardment, you want the last ditch point defense to be very, very reliable.
For both area and point-blank PD fire, each fire control system is assigned a target salvo and fires all weapons at that salvo. The total number of hits is calculated and that number of missiles are removed. This can lead to overkill if there are more hits than missiles but those hits are not carried over to another salvo. Its a good idea to have multiple fire controls so you can fire at multiple salvos.
This is a little more efficient defence-wise because you don't get two successful shots at one missile while missing a second. However, this is compensated for in two ways. The fact that a fire control can only shoot at one salvo means you can overkill at a salvo level rather than at an individual missile level and this inherent efficiency is already factored into missile defence. If I change the mechanics so that each weapon targets an individual missile within a salvo, I would probably have to improve missile defence to compensate for it.
In any event, five seconds is a long time in close range beam combat. With computer controlled targeting, there would probably be time to fire at every missile with a single shot, if you have more weapons than missiles, then follow up with second and third shots at the leakers using unused weapons. So the current method may well reflect the likely reality anyway.
Steve