Sensors

[Colin Plummer <ft-play@xxxxxxxxxxxxxx>]

I've been having some thoughts about more restrictive sensor rules - since
the great advantage of PBeM is being able to have multiple "views" of the
game.

The current "fog of war" allows reduced information about ships on a range-band
basis.

My thoughts are heading more along the lines of "submarine combat", each side
making themselves hard to spot at all.  Presented here to stimulate a
discussion - do we want this "submarine style" hunting of targets?  could it
be used just for "dark nebula" terrain?  Has someone else come up with
something better than my half-assed effort? :>

Again, it is range-band based, but more complicated (though since the processor
will be doing the calculations it shouldn't be too bad).

Passive Sensors

Ships will not use active sensors (laser rangefinding etc..) unless necessary
since they can be detected at a greater range than they can detect.

Range bands are 12" (initial guess - might vary with sensor/crew quality)
The effective range band (ERB) is the actual range band with modifiers (I'll get
to those in a moment).

Within 1 ERB, detection is automatic.
Within 2 ERB, there is a 5/6 chance to detect
Within 3 ERB, down to 3/6
Within 4 ERB, down to only 1/6
Outside of 4 ERB - the target is invisible.

So, what modifies the ERB?

 * Target ship profile - how big it appears (related to mass) 
 * Target ship energy emissions - use of drives, weapons, active sensors
 * Whether your ship had the target ship on sensors LAST turn (easier to
   keep something in sight if you know it's there)
 * Whether a friendly ship has passed location data to you.

Ship Profile = square root of (mass/20) - rounded down
  Mass 1-19 (and fighters) = 0
  Mass 20-79 = 1
  Mass 80-179 = 2
  Mass 180-319 = 3
  etc...
  [probably needs tweaking, it will give some "sweet spots" for sensors, but
   without mucking about with complex formula that's going to happen anyway]

  Subtract ship profile from ERB.

Emissions 
  Active sensors = 3
  Weapon fired, or weapon impact, or main drive used (not turns) = 1
  FTL arrival = 4 (or possibly more)
  FTL departure = 4 (but the ship is gone, so it's a "there was a thing here")
  [needs some work on what is an emission]

  Subtract from ERB

Maintaining target solution - range band is 50% longer (so 18") before
  applying other modifiers.

A friendly ship has targetting data = subtract 5 from ERB

So what about active sensors?

You use a firecon (doesn't stop it from being used for firing, but the number
of active firecons remaining limits your ability to use sensors) to "scan"
a fire arc.  Anything in that fire arc will get 2 subtracted from ERB (but
gets the 'active sensor' emission bonus in return).

So I've got a target locked, can I shoot it?

Yes, but that is an "active sensor" emission in that fire arc (and works
exactly like using active sensors) [you must have accurate data to shoot
something]    Indirect fire by missiles (of various types) do not require
a sensor emission, since the missiles have their own sensors.

Can I get information other than a target lock?

[These are just some rough ideas]
If you miss the detect roll, but the target was emitting energy - you get
the idea that "something" is that direction. (must be inside 4 ERB to get a
detect roll however)
Detecting something due to FTL arrival - just get mass of ship?
Passive sensors can determine the CLASS of ship (and related SSD), if and
only if your "side" already knows the ship (so a first alien encounter
scenario will not provide SSD details)
Active sensors will probably show damage (possibly also system damage if
you know the SSD) if the ship would still have been detected at the next
furthest range band (with the same detection roll).

How about civilian ships?

Probably count as emitting energy all the time.

What other things does this open up?

Mines become really dangerous - you have to detect them to stay clear.
Fast flyby attacks will only work if you have a really good idea of the
target location.
Possibility of the use of "sensor buoys" and/or cheap ships to spread out and
provide extra sensor information.
The ability to perform "pincer" manuevers much better, since you may be in
range to start doing damage before the target is aware of your presence.
Extra scenario possibilities.
Extra possibilities in ship design (minimise profile in different fire arcs)

-- 
Colin P (ft-play@xxxxxxxxxxxxxx)