Re: [FT] Sensors and Sensibility(long)

These rules are simpler to play with than they are to
describe. Which is good, because they're pretty long.

Brain's Basic Sensors - an immodest proposal.

Rationale: Why do we want sensor rules?
======================================
I see the primary purpose is to allow "ambushes" and
the "fog of war" to intrude, to add to the gaming
experience. The Tuffleyverse background already
mentions at least one "ambush" , so it would be nice
if we could come up with some rules that would allow
this, while retaining the usual simplicity of everything
on the table being visible.
A secondary purpose would be to allow some "rigidly
defined degree of uncertainty" when setting up a
tactical game - what can be seen within a star system
for example.

To this end, I propose the following rules:

Universal Modifiers:
===================

Double Distances below for each of:
* Improved Sensors on locator.
* Target identified in the previous turn .
* Target is Civilian or Natural Feature .

Halve Distances below for each of:
* Target Stealthed 
* In Cover (ie amongst asteroids, nebulae etc)
* Obscured (ie behind a planet, moored to an asteroid and
camauflage netting over it etc)
* Using Civilian Sensors or those on board a fighter

This is cumulative, so if a target is moored to an asteroid,
camauflaged, and in cover in an asteroid field, distance would be
quartered.

In addition, targets may increase their signature so they
can be detected at a longer range, but never decrease it.

DETECTION:

Detection gives the following information about the
target: Position, Direction of movement, and acceleration.
("Thrust 2", or "Fighter Move 18" for example - if fighters
are escorting or moving in close formation (1") with ships,
the detector receives the ship's acceleration not the fighters.)

Once detected, a FC can be allocated to the target.
FCs have an effective range of 200*, and any target within
this range will be continuously detected provided an FC
is devoted to it.

A ship, asteroid or other object that has been detected but
not identified is represented by a "blip" counter - traditionally
a ping-pong ball on a stand. Additional information - "Military",
"ADAF"	"Thrust 4" etc is best represented by counters.

Any number of Ships, Fighters etc that are within 1" of each other
are represented by 1 Blip, providing all are within 2" of each other,
and they all have the same course, speed and acceleration.

A ship is detected if it is Identified (see below), but the converse
is not neccessarily true.

Passive Detection:
=================
Any target that Operates Civilian Active Search sensors,
Military Active Search Sensors, or ADAF is detected at a
range of 1000** by passive sensors. 

The opponent must be told which of the sensor types above is
operating. Note that a target using Military Active Search
sensors may deliberately use them at low power, in which case
they are detected (and detect - see below) as if they were
Civilian Active Search sensors. FCs that are allocated against
the detecting vessel are themselves detected at a range of 2000***.

Weapons are detected at a range of ( their Max Range x 10).
The opponent must be told exactly which weapon type is
operating, and which mode ( for example, Pulsar-C  not
just Pulsar ). PDS's are therefore detectable at 60", but
note that if an ADAF is operating, that will be detectable a
lot further!

Weapons and FCs that cause detection reveal the nationality
of the ship's builder (not neccessarily the owner...)

A ship jumping or emerging from jump is detectable at a range
of Mass x 100,000****

Active Detection:
================
A ship using active search sensors can detect targets
at up to 3x the identification distance (see below).

IDENTIFICATION:

Passive Identification:
======================

On the first turn of identification, put on the models for
the ships that have been identified. If there are no ships left
in the blip that are unidentified, remove the blip (if any).

On the second turn, the ship's general class (military, civilian,
asteroid, Space Dragon) is revealed. So if using models that
are not representative of the actual ship, you must declare with
accuracy what class the ship is, it's role (Battlecruiser etc)
and nationality.

On the third and following turns, the ship's SSD is revealed.

A target ship is Identified by passive means within the
following distance:

Mass x (0.001 + (Warp Core On board) x 1 + (Thrust Used) x 1)

So a 54 mass ship will be identified at 54.054" if not thrusting,
unless it has dumped its core.

Fighters and Missiles are identified at three times their
move - so a normal fighter would be ID'd at 72" (3 x 24)

Asteroids etc have masses in the thousands to Billions, so
are identified from 20" (for an asteroid about the size of
a small house) to much further. Otherwise the 0.001 factor
can safely be ignored.

Active Identification:
=====================
A ship using active search sensors will identify a target at a
range of 36".

EXAMPLE:

A Heavy Cruiser of mass 80 is sitting amongst some asteroids,
in "Silent Running" mode - with nothing but passive sensors.
It is attached to one asteroid,
of about the same size (a small one) and has had lightweight
covers erected by vac-suited crew to camauflage it. It is
not stealthed.

A Battlecruiser of mass 100 enters the area at thrust-2 with
its active sensors on in reduced-power mode (pretending to be
a merchantman). It too is not stealthed.

The BC is detectable at:
Base 1000 because it is using civilian active sensors (or the
equivalent)
Halved because the CA is amongst asteroids, so the BC is in cover.
 
So the BC appears on the CAs screens as a "Possible Merchantman"
at range 500.

Had it not been operating its active sensors, it would have been
detectable at its identification distance -
(1 (for warp core aboard) + 2 (thrust-2) ) x 100 (Mass 100),
halved because it's in cover, or 150. 

The CA identifies the BC at 150 range. No merchantmen, this...

The BC detects some of the asteroids at a long distance, but
the 80-mass one that the CA is hiding alongside only at 54".

This is calculated as follows:

Basic range of Active Sensors - 3 x 36".
Halved because of operating in low-power mode
Halved again because the asteroid is amongst other asteroids,
ie in cover.
Doubled because the asteroid is a civilian target or natural
feature.

The CA itself would normally be detected at 27" by active sensors.
The wiley captain, however, will be hiding within the blip of
the asteroid.

The CA would be identified at 20", and the game would be up.
However, as the BC gets within 30", the CA activates his
FC and lets fly with his entire weaponload...

PS: * indicates a "rubbery figure" whose meaning is given
below.
* - A long way in any event, from a tactical viewpoint - greater
than any weapon range.
** - A very long way - effectively infinite from a tactical
viewpoint, but not so when setting up a battle.
*** - A very, very, very long way indeed. But not interplanetary.
**** - Interplanetary distances - Light minutes. The idea
is that a big ship jumping in anywhere with Jupiter's orbit should
be detected from Earth, but a small one near Pluto not. 

PPS:
Cost of Improved Sensors: 8 mass at 4 pts per mass = 24.
Cost of Stealth : 10% of ships mass at 3 pts per mass. Minimum 1 mass.

PPPS:

Summary:
halve for civilian/fighter sensors, stealth, cover, obscurity,
double for civilian target, detected before, improved sensors
Active ID = 36" , Active Detection 3x this (108")
Passive detection essentially automatic if target using weapons, FCs or
active 
sensors.
Passive ID = Mass * (Thust+1) or 3x move for Fighters.

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