Re: Sensors

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On Tue, 29 May 2001, Ryan Gill wrote:

> On Tue, 29 May 2001, Derk Groeneveld wrote:
> 
> > Actually, as far as id-ing a target is concerned, almost the reverse
is
> > true for 'passive radar' (ESM). A good ESM suite, supported by a
> > well-filled ESM database, will give you a very solid ID of a target
based
> > on the target's emissions. So perhaps sonar isn't as good an
example? In
> > any case, I wouldn't be surprised if modern day passive sonar has
much the
> > same capabilities?
> 
> That assumes that targets are emmitting. A target at total
> EMCON will presumably be relying on totally passive sensors.
> Say a vessel (in space) moving ballistically and not
> thrusting. 
> 
> By relying on ESM systems you are looking at the various
> fire control radars, navigation radars, long range
> communications, search radar, weather scopes, data links,
> Talk between ships radio, and other electronic garbage that
> ships emmit. 

Yes. But so is any passive sensor. 
 
> Further, just relying on passive sensors to recognize a
> vessel will lead to funny incidents of "seeing" a harmless
> tanker when in reality it is a CVA dressed up with the same
> active emmissions. 

Then again, there's the same risk with active sensors. Also, you;'re
assuming everything CAN be disguised/masked (see below, engines
discussion)
 
> The above has happened in exercises where a very large CVN
> (Nimitz class) was dressed up by the crew with all of the
> correctly placed running lights and apparently masquraded as
> a tanker in civil lanes in the Med. The Red force guys
> waltzed right by it and didn't think to really check her
> out. "Port side watch reports sighting a large tanker, very
> well..." How do you loose a Nimitz Class CVN in the Med?
> Very sneakily....

Similarly, a sailing vessel can be given a nimitz-size reflection by
using
a simple retro-reflector...
 
> If a force gets very careful about how much they emit and
> what they emit, they can get very "dark" to prying eyes. Add
> to that in FT we're talking about using lots of whisker
> lasers for close by data links, ranging data and lots of
> telescopes I suspect. 

Yes, but you're not going to do much ranging until you've acquired the
target, meaning that EITHER passive sensors were good enough to acquire
the target, OR you had to go active anyhow.

> Obviously when you light some one up with beams, or fire a
> missile salvo at them, you've probably just announced for
> all around that you've got "a Leica Astrosystems Ranging
> Laser and Hellseye Mark6 Beam Battery" or "a
> GEC-Marconi-Lockheed Aerospace Mark 23 Fire control radar
> and a Thiokol-British Aerospace Dynamics Lightingstrike
> Salvo Missile launcher".
> 
> All of this goes out the window if you can tell the type of
> plant a ship has just from its use of a captive singularity
> irregardless of the drive using thrust or not. Passive
> gravitometric emmissions could tell the size and probably
> the field used to keep it from hitting the reactor sides and
> making the ship go boom. If its just a fancy Fusion plant
> with a big magnetic bottle you're going to have to get a lot
> closer to tell if its a Big Merchant or a Big Warship, by
> then you can probably read the hull number with your
> Graflex, Inc Catadioptric Telescopes attached to your fire
> control systems. This all assumes that the target at 48MU
> you're looking at don't thrust at 4MU/sec/sec with enough
> engine effulx for a Foch Super Carrier making it
> obvious its not a 150 Mass bulk carrier).

Similar to modern passive sonar, where the noise can be related to
specific ships.
  
> So I guess the question is, what kind of drives are they?
> Thats the first thing. 
> 
> Second is how much passive emmissions do the ships give off?
> You know something is there. How far beyond 54" do you know?
> (TK drive emmissions are another thing, boy this long range
> sparky stuff gets tricky...)

Yup. So what PSB do you want to make up for your desired game effect? ;)

Cheers,

   Derk
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