(FT) ECM,never leave home without it

2 posts ยท Oct 20 2000 to Oct 21 2000

From: Bif Smith <bif@b...>

Date: Fri, 20 Oct 2000 15:23:59 +0100

Subject: (FT) ECM,never leave home without it

I was just reading over the back mails about missiles, and I thought you might
be interested in a idea I had a while ago about ECM vs missiles.

To explain it, I will have to go back to the begining and explian my
reasoning about sensor, ECM, decoys and missiles, so here goes-

ECM & Sensors

In FT, sensor were discribes as having a range of 36MU for passive sensors,
and 54MU for active sensors. Now, it may just be me, but in every sf novel
I`ve read, passive sensors usually out range active sensors. Assuming systems
comparable to todays tech, we can see the wobble in another star using passive
sensors (a.la hubble), but how long would a radar pulse take to get there and
back (this is a retorical question, don`t bother with a answer). Even on a
closer range scale of a battle, you would still have a time delay on
infomation getting back to you in time for you to react to. Therefore, I think
passive sensors sould have twice the range of active sensors*, but be very
limited in the infomation they give. My preference is for active to have a
range of 24MU (standard), and increase by 6MU for enhanced, 12MU for superior
sensors. Beyond that range, the target can be detected by passive sensors, but
they only give the aprox. size of the
vessels concerned to within 50 mass (i.e.-jean d`arc masses 250-300
mass). If using ECM, even this isn`t disclosed, all they`ll see is the bogey
marker, with no idea of size at all. Against active sensors, the ECM would be
rolled against. My idea was for using the masses given for ECM to represent a
class 1 level ECM system, a.la. PBL`s, and the greater the ECM level, the
harder it would be to penitrate. The ECM would work on the size of the ship,
in 50 mass increments (i.e. 01 to 50 mass = size 1, 51 to 100 mass = size 2),
and would have to be rolled under on a 1d6 to defeate the
ECM involved. For each atempt at defeating the ECM, you get a -1 to the
roll
(plus an extra -1 with superior sensors, -2 with enhansed). The ECM
would
reduce the size of you ship by -1 for each ECM level you carried, and
each ECM level would be a separate ECM symbol on the SSD, capable of being
destroyed/disabled by a threshold check.Multipul sensor suits
(i.e.-3xsuperior sensors) would be allowed to enable a ship to identify
more than one target at once, or for each sensor above the first allocated to
a
target, you gain a -1 on the defeating ECM roll. Any extra sensor suits
must be the same grade as the primary suit, and have their own damage icon on
the SSD, making them suseptable to dammage. This would enable ECM to be a
battlefield weapon that could be used in the game, instead of a strategic
weapon, whereby you bluff you opponents into reterating without and combat, as
shown in the rulebooks. It also represents the differences in energy outputs
between a DD, and a SD. The reason I chose a range of 24MU for active sensors,
is that it makes missiles (especially the variable range HH type missiles, as
I`ll explain later) vulnerable to decoys (as I`ll explain later also). For
actually knowing where you enemy is, this could be represented by a grav
sensor, that can detect a active drive or screen out to a long range (say,
200MU with no details, just theres a ship at xyz
co-ordinates) , and also the hyper pulse of a ship arriving. All sensors
and
ECM/decoys would be disabled if a command bridge threshold check fails.

Area affect/individual ECM

To represent the difference between area affect ECM and individual ECM, we can
say that with indiviual ECM, if you use your sensor suit, the target can tell
the bogey that is using sensors (you tell your opponent, he has to remember).
With area effect ECM, the opponent does not know the bogey using sensors, just
the general direction (one of those 6 bogeys over there). Also, area effect
ECM provides ECM for any bogey within,say,10MU (only an example, havn`t any
decision yet as to what`s ok), as opposed to individual, that provides ECM for
just the ship mounting it. This also opens up the posibilities of say a DD
protected by a SD`s area ECM, providing sensor data for the SD`s missiles,
without the SD exposing itself. To allow this, both ships must mount ADFC, to
represent the computers and rapid data com.systems for exchainging the data
needed. Also, only works within the ADFC radius of 6MU.

Summary

Jean D`arc size 6 (270mass), refitted with level 2 individual ECM (4
mass/40
points), effective emitions level 4.

Scouting DD, enhansed sensors x1, roll under 4 on a 1D6 - 2* at a range
of
36MU (active sensors range), to reveal data on target/replace bogey
marker. Roll under 4 on a 1D6* (no modifiers, out of active sensor range), at
a range of upto 72MU, to replace bogey marker.
*-1 per turn attempted scanning

BIF`s MT/HH variable missile

Range-24MU per turn
Endurance-3 turns
Cost-6
Dammage-4D6 (1/2 armour, 1/2 hull)
Mass- 2 per missile
Engaugement/attack radius-6MU on first turn, 5MU on second turn, 4MU on
third turn**
Notes- Launched from a internal launcher like SML`s (mass-3, cost-9,
1arc
fire/ mass-4, cost-12, 2 arc fire, thinking along the line of HH
broadsides/chaisers for this system), may use secondary movement*** like
fighters in exchange for 1 turn endurance, but the attack radius reducess to
the next lowest setting, must be decided before launch****, maneuvers like
fighters.

Missiles vs ECM

If there is only one target, the ECM would gain you nothing against missiles,
whether the enemy has penitrated you ECM or not. But, if your ECM is still
efective, you could use decoys against the missiles. The decoys would be a
small drone, equipt with a weasel emmiter, that would emmit the same sensor
returns as the mothership (or any other ship). This could be represented by
instead of 1 bogey marker, there is now 4 bogey markers
(mothership + 3 decoys). If you changed vector as well, the enemy would
left guessing as to whitch is the target, and have to prenitrate the ECM of
each in turn to decide. As given above, if the decoys were launched in the
turn that the missiles would attack, the firer would have to decide how many
missiles attack each target. Then the missile attack is resolved as normal,
but with those missiles that attacked the decoys would be wasted shots. Of
course, the decoys would be dead (bang).

Decoys

My decoys would have to be carried aboard a ship (not nesasserally the ship
using it/ the ship it mimmics), at a mass of 3, a cost of 21*****, and
be deployed at the start of the movement turn. It moves as a normal ship, with
a thrust upto 8 (keep it at the same as the mothership it`s mimmicing, or the
enemy will notice), with the launching ships velocity at the start of
that turn. If you think the cost is high/low for this system, remember
that it is efective at diverting MT type missiles that ignore sacrificial
ships/escorts, and it removes mass from offensive systems to defensive
ones (after all, you are not going to mount just one on your SD, are you?).

*My reasoning being that it takes twice as long for a radar pulse (or
whatever) to travel there and back, as it does for EM emmisions (or whatever)
to just travel back, therefore, if you have the same time to react to the
infomation under combat conditions, the passives have twice the effective
range for the infomation collected.
**To represent the missiles limited sensors/ECCM, and the shorter
reaction time for the mothership to update the missiles target systems. Can
attack any target within range as decided by firer, not just the closest.
***May use all three turns endurance in a single turn, and move 24MU, a
secondary move of 12MU, and a tertiary move of 6MU, then engauge any target
within 4MU ****When launching, next to the missile symbol, write S for 2 turn
normal
and 1 secondary after both normal moves (i.e.-sprint setting), or SS for
1
turn movement and 2 secondary movements (i.e.-supersprint setting).
*****Mass and cost may be altered (not just the decoys), only a rough guess at
the moment. Depends on feedback from more enlightend members (Oerjan Ohlson,
waiting for your reply?).

P.S.-These ideas are the first time I`ve put all the different ECM,
sensors, decoys together in one set of rules, and may need amending in light
of feedback (if they don`t, it`ll be a first). I don`t think I forgot to
include or mention anything or reasoning behind it, but if I did, I`ll try to
reply to any points raised.

P.P.S.-My spelling is aufull, sorry for any mistakes.

From: Laserlight <laserlight@q...>

Date: Sat, 21 Oct 2000 01:32:10 -0400

Subject: Re: (FT) ECM,never leave home without it

From: bif smith <bif@bifsmith.fsnet.co.uk>

> I`ve read, passive sensors usually out range active sensors.

Of course, if one side is using active. If you bounce a signal off a target
and get a usable response, the target will be getting your signal, four times
as strong as the bounce you're reading.

If you're both using passive, then passive may be shorter range than active. I
assume here that some degree of effective stealthing is possible, although I
haven't come up with a plausable way to hide the ship's IR or thrust plume
signatures.

> answer). Even on a closer range scale of a battle, you would still

No. If the target is X distance away, it's still that distance away whether
the signal being returned from it is a reflection or its own noise.

<snip>

The rest of this sounds pretty reasonable. Of course it's 1:30am too...