Derk:
1) EW - Any smart EW no longer does broad spectrum jamming. You don't
have the power to manage that kind of jamming (or so I've been told by people
in the Canadian intelligence community with military EW backgrounds). So,
assume that the jamming is sophisticated. In order to jam, you must emit.
Modern ESM techniques are extremely sophisticated too and locating any unit
that goes active (regardless of what type of emission) is going to be none too
difficult by 2183. Even now, you go active, and you attract HARMs from air
delivery plus artillery. That is why most EWOCs, when operating, will operate
for a time then get the heck out of dodge to avoid the counterstrikes. It
takes a bit of time to localize you.... your window of work... but figure this
will reduce in the future. You can't be totally sneaky and still effectively
muck up a powerful transmission. It will always be paper scissors rock, but
nowadays EW assets that go active that don't move shortly tend to get whacked.
Or at least so goes the theory on this side of the big pond. It was the
doctrine I observed in CF EW forces our infantry unit was protecting in Europe
on excercises in the late eighties. I don't think that much has changed,
except how quick you get localized...
2) Advanced Sensors - My take is opposite - advanced sensors are
passive. The better the quality, the less need for active sensors, hence the
less detectable.
3) Squads and Fireteams: Fireteam gets two actions, acts on its own. Probably
should stay within 100m
(or less!) of its fellow fireteam - they really are meant for mutual
support. Both activate and act independently, but they get one morale
counter, and check as a unit for morale stuff - and when one takes
casualties, obviously that affects the whole unit. (The idea of me not caring
if a guy outside my squad gets whacked is another shortcoming of the current
system.... but no one does it well so I'm not blaming Jon).
4) AT version of the ATAC....
I'm _sure_ that's a knock off with a hacked turret that someone has
molded.
5) If someone was looking for platoon sergeants etc, my original
interpretation is reiterated here: Leaders and NCOs as Individuals
Rationale: Platoon officers and NCOs tend to attach/detach at will and
go where they are needed and the fact they are on the radio would freeze the
command squad in SG2. If they are treated as individuals, then they can
freely attach/detach and make themselves present as required.
As per the individual rules in the SG2 rulebook, these figures can attach
detach at will. When attached to a unit, they temporarily replace the existing
leader (so a weak squad can be taken over by the grizzled platoon sergeant).
Platoon Sergeants Rationale: A lot of the leadership in units is provided by
NCOs. They can often initiate things when the Lt. is otherwise occupied.
Treat the Pltn Sgt and Lt as co-equal command elements (in the sense
that the Lt can't reactivate the Sgt to reactivate the squads again...).
However,
the Platoon can only have a total of 3 transferred command - either 2
from the Lt and 1 from the Sgt or vice versa in any given turn (the obvious
exception to this being if higher command reactivates the Pltn Ldr).
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> On Sat, 24 Mar 2001, Barclay, Tom wrote:
> Derk:
SMART jamming is not broad spectrum. But even on narrow spectrum, there's a
BIG difference between noise jamming (basically shouting so loud the sensor
can't hear) and responsive, deceptive jamming, where you try to confuse a
radar with false range or direction information.
Now, assuming ultra high speed digital memories are commonplace in the future,
deceptive jamming becomes ever more attractive. Then, it's suddenly very hard
to discern between a true radar echo, and a signal generated by the jammer. As
the signal strength emitted is now in the same
order of magnitude of the radar _echo_, it's MUCH harder to _detect_, or
to lock a HARM on (since you don't want the harm to lock on genuine radar
echoes). Of course, this is between stand off and on board jamming.
> Even now, you go active, and you attract HARMs from
Yes, if you go for noise jamming, you'll announce yourself to the world as a
target, for sure. Andyes, in the future you'll probably be dead sooner.
Howebver, this still isn't truly intelligent jamming.
> You can't be totally
A _lot- has changed in the _type_ of jamming employed. Of course,
jamming the opponents communications is WAY different from jamming sensor
attempts. To jam communications, you have to interfere with HIS use of the
bandwidth (therefore need more power), instead of slightly misdirecting a
sensor attempt.
Mm. Maybe I shoiuld dig up my EW textbook and try and make a coherent story
here, sometime;)
> 2) Advanced Sensors - My take is opposite - advanced sensors are
Basic sensors are by definition passive, unless you include 'Hello?? Anyone
there?". Anything above basic will probably be to some degree active. But
yeah, I can think of some very advanced passive ones as well.
So maybe it would be: Basic - passive. Enhanced - active & passive.
Advanced: Mainly passive, some active etc.
> 3) Squads and Fireteams:
A simple rule like 'seeing a friendly unit rout/retreat causes morale
check' would help?
> Have a good weekend guys!
Likewise!
Cheers,
> Derk Groeneveld wrote:
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So,
> > assume that the jamming is sophisticated. In order to jam, you must
Actually quite the opposite. Truly basic sensors (more basic than the basic
level sensors described in MT), such as those mounted on freighters are
entirely active because they only have to avoid objects, not shoot at them,
and power is cheap while sensitivity is expensive. FT warships (including the
Komarov and Von Teghettof) are actually too small and maneuverable for the
double transmission delays of active over passive sensors to provide an
adequite fire control solution.
Warships will not use active sensors in the same fashion as the civilian
vessels. Warships will use their active sensors to take a snapshot of a bogie
first detected by passive sensors. The snapshots are taken with microwave
"flashcubes" derived from explosively pumped, high powered microwave weaponry,
which are destroyed by the energies that they focus on the target (vessels
carry a large number of these small and expendable devices). The vessel's
passive sensors (and those of other vessels in the formation) use the
reflection of the single pulse to determine range, size and shape of the
target. Because these images are used to aid in the passive tracking, they
need not be taken very often. As the pulse is
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> On Sun, 25 Mar 2001, Richard and Emily Bell wrote:
> > > 2) Advanced Sensors - My take is opposite - advanced sensors are
> Actually quite the opposite. Truly basic sensors (more basic than the
I may have used the wrong term, buty I was referring to the d4 you get for Mk1
eyeball...
And we were discussing stargrunt rather than FT;)
> Warships will not use active sensors in the same fashion as the
On the other hand, such extremely high powered pulses are just about
impossible not to detect. Also, there's a lot you cannot measure this way,
which you could measure with a longer, low powered signal, like target
speed (doppler shift). Problem with super-broad band flashes is that you
need super-broadband receivers, which means receiving a HECK of a lot fo
noise. And since you're doing only very short pulses, you have no means of
discerning between noise and a coherent signal, no processing that can help to
any extent, except inbetween successive PULSES. Which is orders of magnitude
less effective than what you can get from a coherent signal processing.
Instead of going for very 'loud', short pulses, you could use long, modulated,
much lower power signals. harder to detect, and give you a big performance
boost against noise.
I'm curious where this idea came from, and what makes you state it as if it
were chapter and verse? Is it FT canon?
> The PDS's employ a more conventional active sensor system as the range
Makes sense.
Cheers,
> Derk Groeneveld wrote:
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The problem with a "low powered" signal is that the reflected power that can
be detected at the sender falls off at the fourth power of the range, but the
power detected at the target only falls off with the square of the range. In
space, if you can detect a return from a ship at one thousand kilometers (10^6
meters) with your "low powered" signal, then that signal can be detected at
one billion kilometers (10^12 meters). You get a lot more, with less danger of
giving too much away, by examining the emanations of the target. Target speed
is hard to deduce if there is only one sensor, but two sensors on one large
ship, or two sensors on seperate vessels with exact knowledge of relative
positioning. The flashcubes are for quickly generating extra information, or
for lone small ships to generate a range, from which they can extrapolate a
bearing and speed. The other use for flashcubes are objects that only barely
radiate, usually by not applying drive energies and by having their PDS units
switched off.
> Instead of going for very 'loud', short pulses, you could use long,
Loud and short reveals the least information about yourself as you interrogate
the contact. Low power, active sensors in space combat is very relative. You
either cannot detect a target at a useful range, or you are announcing your
presence to the heavens.
> I'm curious where this idea came from, and what makes you state it as
A 1988 (may have been 89 or 90) issue of IEEE:SPECTRUM described high powered
microwave
weaponry aimed at applying EMP-like surges on enemy equipment. One of
the methods of powering such a device is an explosively compressed coil, as
these have the potential to convert 25% of the chemical explosive's energy
into electrical output (explosively compressed coils are why you could see
belt fed, autofiring energy weapons spewing out spent casings outside of badly
written anime). That the resultant explosion will destroy the microwave device
is not an issue as the pulse has left the travelling wave tube before the
explosives disassemble the device. You simply make the TWT barely capable of
handling the power once. I merely posited another use for these things, as
there are applications for terawatt radars (peak) with low pulse repitition
frequencies.
I describe them as "chapter and verse" simply out of artistic license (being
unable to write even to the length of a short story leaves me with few outlets
for my desire to write science fiction).
> > The PDS's employ a more conventional active sensor system as the
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<DISCLAIMER>
I'm _not_ familiar with full thrust, but as this discussion originated
as a StarGrunt question...
</DISCLAIMER>
> On Sun, 25 Mar 2001, Richard and Emily Bell wrote:
> Derk Groeneveld wrote:
signal,
> then that signal can be detected at one billion kilometers (10^12
Yes, no doubt that passive sensors have a significant advantage. But IF you're
going to go active, I'd MUCH rather use long, low power transmissions, than
short high power transmissions. Due to the modulation on the signal, you can
get in increased signal to noise ratio, and hence the same performance as a
high power transmission, with a MUCH lower probability of intercept.
> Target speed is hard to deduce if there is only one sensor, but two
With the distances involved in space warfare, there is no way you can use the
parallax from two sensors on the same ship, until the target is REALLY close.
seperate ships work, of course, but as you said, your position info
needs to be frighteningly accurate. Narrow-beam ranging inbetween the
ships or somesuch, I guess. Very tight-beam communication between the
ships would also be a prerequisite. Asuuming you wouldn't want to broadcast
your position with your comms traffic, that is;)
> The flashcubes are for quickly
I can imagine attackers coasting in from long distances well outside your
sensor range? I don't see why they'd have to do their acceleration burn while
in your sensor range. Of course, once they'd decelerate to engagement
velocities, they'd light up their engines. Doesn't strike me as an altogether
outlandish concept.
> > Instead of going for very 'loud', short pulses, you could use long,
You either cannot
> detect a target at a useful range, or you are announcing your presence
Are you familiar with low power frequemncy modulated continuous wave, or pulse
compression techniques? Both work with low power signals, which, lacking the
very same source of modulation, are hard to detect. They are techniques
currently in use and continuously being expanded upon. They work, and I can't
think of a single reason why they wouldn't work in space.
> > I'm curious where this idea came from, and what makes you state it
I guess I wasn't very clear. i have no problem with the concept of the
transmitter. I do, however, havbe a problem with these very high peak
signals offering an _advantage_ in being harder to detect, than chirped
(frequency modulated) longer duration, low power transmission.
> I describe them as "chapter and verse" simply out of artistic license
Okay, no problem:) I never played full thrust, so as far as I knew, this could
have been straight from the rules.
> > > The PDS's employ a more conventional active sensor system as the
The more I think of it, the more I am convinced that with the ranges that
space combat suggests, you're going to need such high update rates for
general anti-shipping weapons as well, unless you're talking homing
missiles etc. A fraction of a milli radian off-target and it's going to
be missing by miles? What sort of ranges does FT combat happen at?
Cheers,