Missile Defense

"The focused beam is made possible by the adaptive optics."

That's a question of fact, is it not? A question of fact that applies to a particular system, ABL, in the tactical contexts actually involved?

Suppose, by chance, that people didn't trust my objectivity completely, or yours either...

"...Technically that's true -- with a beam focus that the dialog has already ruled out, and that gisterme has stopped arguing for..."

That's another one of your WHOPPERS, Robert. The focused beam is made possible by the adaptive optics. That was pointed out just yesterday...

"...If I've made a mistake here, what would it be?..."

It would be that the reference point for the ABL application of adaptive optics is the brightly illuminated target. That's a great reference point. And the reason for the 1 arc second resolution limitation for traditional ground-based telescopes noted Caisson's book is due to atmospheric turbulence...

This schematic diagram of the process involved in adaptive optics is very good, and I hope people look at it carefully. I hope we can agree that this schematic, and language connected to it, are well grounded references helping to define what adaptive optics is http://cfao.ucolick.org/images/aos_small.gif

( To get a bigger, clearer image of http://cfao.ucolick.org/images/aoscheme.gif . ...

continued...

The first one you should know. The second you mignt wonder about...

"...Do we agree that there is no feedback loop good enough for ABL to work? (It seems to me that we should agree about this.)..."

gisterme 2/8/02 3:06pm

That post shows why there's no physical reason that such a feedback loop couldn't work.

"....Or should we work through the argument in detail?...'

There's plenty of detail in the link referenced above to show that optical resolution is not a problem...

You can't be honest, Robert. Of course I don't agree with that. It's not the truth...

I have some reason to think that some responsible people are watching...

"...There are, of course, problems in arguments that depend, in essence, on numbers, on issues of "how much" -- when the numbers, very often, are classified..."

That's a false premise. No numbers have been quoted that are not based on published references from unclassified public sources presented along with the numbers. The numbers speak for themselves to show why lasers would be workable for MD...

How much light would make it back to your sensors?..

light travels in straight lines, and c is very fast. Those are conveniences. But these facts don't avoid other problems -- and light coherence versus decoherence (the difference between lasar and ordinary light) doesn't either...

Adapts to the particular structure of eddies, and densities, in the light path between the target and the missile - a structure of eddies and densities that is stable for a short period of time (tens of milliseconds, at most) -- for a moving target and a moving airplane.

Mazza: The reference beam reflects off of the missile and is viewed by the ABL systems...

The adaptive optics adapt to the atmosphere not the missile. The reference beam reflects off of the missile and is viewed by the ABL systems. Any distortion is caused by the atmosphere not the target...

I don't doubt that adaptive optics works -- in specific cases. A star is a point source reference --- and the adaptive optics can adapt so that the real optics gets a better and better approximate focus on that point source (and the adaptation, these days, can be faster than the changes in air flows.)

But in the ABL case - the adaptive optics has to adapt (and adapt fast enough) to the target .

There is no "ideal reference" to the target analogous to the case of the star...