Re: GPS BASICS: WAS:Re: BASICS: Property Rights

Spike Jones (
Sun, 13 Dec 1998 18:20:31 -0800

> Spike Jones writes: > today there are gps guided....

> Eugene Leitl wrote: Spike, are there purely optically guided missiles
> out there? I could
> think that it would be difficult for subradar missiles (would require
> some descendant of the silicon retina technology to recognize anything
> in all the blur), but for those coming right out of the blue
> (ballistic) it would be difficult to jam the CCD, but by very
> powerful lasers or nuke flares, and there would still be GPS
> and/or inertial navigation available.

gene, i am reluctant to comment on guidance, as i am more of propulsion / space type, but i may be able to help find the answer. there is janes defense websites that give a pretty good rundown on the systems that are in the unclassified areas. as for optically guided systems, my intuition tells me that frequencies that high (800 nanometers and shorter) would not be very compatible with ballistic trajectories because you need a transparent medium in front of the seeker which must absorb hellish heat during reentry. such a thing is being tried on the thaad antimissile missile, but the
velocities are much lower. thaad requires an optical window made of a single piece of manufactured sapphire, so its waaay uncheap. (we had one
disappear in our lab, and we thought they were gonna throw us all in jail. it mysteriously reappeared.) using a sapphire window on a ballistic reentry body doesnt sound very doable to me.

tell me again what you thought the advantages of optical spectrum? seems to me it would be plenty easy to jam or spoof those way high frequency seekers the same way its been done on battlefields since forever against the two optical seekers in your head: smoke, darkness, magnesium flares, etc. spike