From:	Mongoose <m0ng005e@*********.COM>
Subject:	Re: Ultrasound vision
Date:	Wed, 3 Feb 1999 12:47:53 -0600

: One caveat here, though. If someone else is using an ultrasound
:sight on the same frequency (or frequencies), you will be able to see
:them. They will look like a bright light (again, just like having a
:flashlight strapped to your gun). In this sense, ultrasound is a double
:edged sword. Like all other active sensors, it provides information but
:may tip off your opposition to your presence.

Supposedly the Ultra Sound sight includes some sort of pulsed /
frequency hopping feature to avoid that- rather like the Ir "strobes" used
to jam heat seakers, I suppose. That wouln't prevent it from being
noticed as a loud (high frequency) noise, but could make "imaging" the
source with another scope, or even localizing it with apropriate hearing,
difficult.
Since I mentioned IR strobes- would it be possible to build an IR
flashpack? Would it mess with lowlight vision? Could you make its
frequency low enough that it ONLY affected thermo-vision? Would it be
bigger / heavier than a normal flashpack, or about as compact? (I'm
guessing compact, since IR remotes don't need to be big).

Mongoose