Re: Lag....

> Actually, another interesting related problem is the degree of error
of
> your firing mechanism.  That is, how much does your aim have to be
> "off", in order for the shot to be spoiled.  Actually, the original
> post may have been trying to point this out.
> 
> Assume a "spoiled" shot misses by 100m.
> Assume the range is 100,000,000m.
> tan(theta) = 100/100,000,000
> which is 0.00005729578 degrees.
> 
> Which means you have to have some pretty well calibrated guns in order
> to aim to the level that we're talking about (it seems to me).

The unacceptable error is 100 metres in 100 million metres, ie 1 in 1
million. So if the end of the weapon is deflected by 1 part in 1
million, the shot will miss. Assume a 10 metre long weapon, this means a
deflection of 1/100,000 of a millimetre.
Not impossible, but not easy. Then add tracking errors. The ship itself
is not infinitely rigid, and will flex somewhat as the thrust changes.
Basically, you need a lot of computation, a lot of sensors within the
ship to measure distortions between sensors and weapons, and a
mirror/lens that reacts at light speed or close to it.

Note that in Naval Combat today, typically a Frigate will flex 0.5-2.0
degrees between the location of a weapons mount, and a sensor mount, in
sea state 3. Sea State 6 means at least double, and the pitching of the
ship can cause a 76mm gun barrel to go at least a degree off true.

The next problem is scanning using EM sensors. Probability of
counter-detection is approximately proportional to Peak Pulse Energy.
Probability of detection is proportional to average energy. So you try
to spread the pulse, to have a low peak, yet high average energy. But
this means dwelling on the target for a long time. Automatic Trackers
often use 2/3 or 3/4 logic to avoid false alarms. (2/3 means if you send
3 pulses, and any 2 of them correlate with a constantly-moving object at
a reasonable speed, then you generate a track).

In space, you don't have sea returns, seagulls etc. But you do have dust
particles, large EM sources (stars), etc etc. Now add decoys - a light
balloon with a small rocket motor, and it becomes tricky.

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