Re: [FT] Sensor Range Question

Beth Fulton wrote:
> 
> G'day Jerry,

Howdy Beth.
 
> Derek also just checked
> out his his Harpoon 4 sonar annex and as a rule the sonar systems with
both
> active and passive modes have an active range greater than there
passive
> range, so hopefully we haven't stuffed up too badly. Basically the way
we
> thought about it was if you're standing in the dark you don't recieve
a lot
> passive info (i.e. not much light so don't see much), but if you start
> swinging a torch around (i.e. actively looking then you're more likely
to
> see stuff that's further away) - once again hope we didn't screw up
too bad.

Hmmm.  I guess it's because I'm equating to ESM and passive; I remember
reading that you can read a radar pulse (or a sonar pulse) from a 
much greater distance then the generating source can pick it up
(assuming
no quirky stuff like line of sight, thermal layers, that sort of thing.)

But the idea of passive tracking (i.e. sticking your eye to a telescope)

and ESM (i.e. sticking your ear to a giant RDF set) corrects that
problem.

> >So that gives half a light second passive, 2 light seconds active,
> >2.4 light seconds using 'ESM.'  Hmmmm.
> 
> And what does that mean? Good Hmmm, bad hmmm, or just hmmmm I 'd
rather be
> thinking about something else at lunch? ;)

1 am over here.  (8-) 3 am now; as I mentioned in the other post, I just
watched the Dallas/Edmonton Hockey Game.  Gah.	

Actually, I'm just thinking what it means in terms of 'real-life', 
reaction times, that sort of thing.  Nothing in particular.
 
> >I think Laser had a point
> 
> Does that make him a laser pointer (as in the things you use in
seminars) -
> OK very sick but I've been at work WAY TOOO long already today.

Signs you've been playing a little too much Full Thrust, me thinks. 
(8-)

J.

-- 
     *** Jerry Han - jhan@icom.ca - http://people.canoe.ca/jhan ***
"There once was pretty good nation, Pretty proud of the greatness it
had,
	 Which learned much too late, If you want to be great,
  Pretty good is, in fact, pretty bad." -- Charles Osgood - TBFTGOGGI