In article ,
(phil hunt) wrote:

If you are manning a passive sensor, the planes won't know where you
are unless they are virtually on top of you, say a few hundred
meters away. By which time the planes are already dead.

A few hundred meters. Except that in a high/high/high precision strike
mission, the closest the planes get to you is nine miles straight up.

Er, no. An observer with modern IR and visual electron systems,
linked to a computer network.

As Phil busily reinvents the WWII Ground Observer Corps...

Once the first has, the second knows approximately where to look.

And by the time they figure that out, the first guy's lost it. The best
you could hope for is a whole string of guys saying "I saw a plane a
minute or so back." Run a half-dozen planes through at a time, and
suddenly half of your planes get through with no effective ID.

You also lose them for 1/2 of the day (pure optical sensors are not too
good at night), on cloudy days, if there's smoke in the way, if the
sun's behind the target... and you need a *lot* of them. With the
curvature of the Earth in the equation, you're going to need a linked
ground observer station every 20 miles or so - at *best*.

I was assuming they'd be closer than that.

So, for a country the size of, say, Iraq, you'd need an observer every
ten miles (each being responsible for about 30 square miles - you have
to have some overlap), linked together with a modern computer/comm
network. You'd have 6000 observer stations, each with at least four
observers on duty at all times, hoping for clear weather. And only
working in daylight. Manpower alone would take up about 24,000 people
on duty... with support crews, tech, extra coverage, you're looking at
30,000 to 50,000 people. For a system that only works part of the time,
at best.

What if each launcher only contains one missile? Or the launchers
are mobile, and move after every launch?

You keep putting restrictions on the usefulness of your system...

Note that there's no need for the launchers, radars, and other
sensors to be particularly close to each other.

No, you pretty much killed the whole thing with the manpower
requirements for the optical part.

People *do* use visual acquisition and tracking. The British army
for example.

Everyone does, sorta. Nobody *relies* on it any more, though, because
it's really not that effective for anything other than "hey, look, a
plane," or "did you hear something?"

--


Remember: Objects in rearview mirror may be hallucinations.
Slam on brakes accordingly.