Re: UNSC beta and FB3

--- warbeads@juno.com wrote:
>
> He is using seeker and sensor as different things.  A most "un-war
> game" thing to do.  I never have heard them used that way in any
intel
> briefing.
> 

I made the distinction to prevent obfuscation by anyone trying to
assert that using a *passive sensor* rather than an *active sensor*
means that the *seeker* is "not active".

That being said, here are the definitions in more detail than I thought
was needed.  Caps are for emphasis only.

1) The SENSOR is a sub-system of the SEEKER.

2) The SENSOR is the system that detects radiated, emitted, or
reflected energy or signals from the target.

2a) A PASSIVE SENSOR only detects energy or signals from the target. 
It can detect radiated energy (such as thermal/IR), emitted energy
(such as from the target's own active systems), or energy reflected
from an outside source (such as laser designation or radar from the
launch platform).  A passive sensor does not emit any signals and
therefor is more difficult for the target to counter, or even detect
it's operation.

2b) An ACTIVE SENSOR emits energy and/or signals, then detects the
reflected energy/signal.  The most common example would be a missile
emitting a radar signal and detecting the return or a torpedo emitting
sound pulses ("pings") and detecting the return.

3) A SEEKER takes information from the SENSOR (of whatever type)
processes the data and makes decisions about what is a real target and
how to steer the weapon to that target.

3a) An ACTIVE SEEKER is operating.

3b) An INACTIVE SEEKER is not operating.

Sea Skimming and other OTH missiles have the seeker inactive during
their approach to the target area until a predesignated point to save
on battery life (the "pickle") because the target is not visible even
if the seeker was active.  At that predesignated point the seeker is
activated and begins searching for a (or the) target.  This is often in
conjunction with a "pop-up" maneuver" where the missile rapidly climbs 
to gain a wider field of view and then begins the target acquisition
search.

A terrain following missile has one or more sensors and a navigation
system operating during flight to detect terrain features and compare
them to stored data and the intended route.  This is separate from the
seeker which is activated at a predesignated point to search for the
target.

AAMs and SAMs are pickled on the launcher, and the sensor unmasked (or
turned on).  The operator confirms  that the senor can "see" the target
and that the seeker has properly identified the target.  The missile is
then launched with the seeker active during the entire flight time.

This can use passive sensing, active sensing, or a combination of both.
 It can also involve the launch platform or a third party directing
energy or a signal to the target and the missile detecting the
reflected signal.  In this case, the target can know that it has been
illuminated, but cannot use that signal to track the missile itself,
only the source of the signal.	Some missiles use several types of
sensors in combination to reduce the effectiveness of any
countermeasures the target might use.

Some systems uses both passive and active mode sensors either in
sequence or simultaneously.  For example, a missile might use both IR
(a passive sensor) and radar (an active sensor) to distinguish the
target from decoys like flares and chaff.  Or a torpedo might use
hydrophones to passively home on a target's noise, then switch to an
alternating sequence of active and passive sensing (called
"ping-and-listen"), then in final acquisition mode begin continuous
active sensing ("continuous pinging").

J