Another Take on CT Sensors

[BillDowns]

May I pose a couple of things, WJP?

What is the reasoning for using the power plant size for determining the split between the 3rd and 4th bands?

IMO, active sensors should either have a much shorter range than passive, or - my preference - a fixed range for the class, since they send out a signal and have to receive an "echo".
</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;"> Active Sensor Reach
Class I, with range of 15 bands.
Class II, with range of 20 bands.
Class III, with range of 30 bands.
Class IV, with range of 40 bands.</pre>[/QUOTE]One example.

Use of active sensors also ought to extend the passive detection range to it's range. I.e. a Patrol Cruiser lights off his actives and the Far-trader can now pick him up 15 (the Far-traders' reach) + 40 (the Cruiser's active reach) hexes away on passives, for 55 total.

First tactical rule in today's navies: the first to go active gets fixed first.

 

[BillDowns]

May I pose a couple of things, WJP?

What is the reasoning for using the power plant size for determining the split between the 3rd and 4th bands?

IMO, active sensors should either have a much shorter range than passive, or - my preference - a fixed range for the class, since they send out a signal and have to receive an "echo".
</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;"> Active Sensor Reach
Class I, with range of 15 bands.
Class II, with range of 20 bands.
Class III, with range of 30 bands.
Class IV, with range of 40 bands.</pre>[/QUOTE]One example.

Use of active sensors also ought to extend the passive detection range to it's range. I.e. a Patrol Cruiser lights off his actives and the Far-trader can now pick him up 15 (the Far-traders' reach) + 40 (the Cruiser's active reach) hexes away on passives, for 55 total.

First tactical rule in today's navies: the first to go active gets fixed first.

 

[Supplement Four]

--UPDATE--

I'm thinking this--

#1 - That the Computer Model number can't be a DM on the sensor roll. (I can't have a +9 on that roll unless I want Model 9's...and anything over Model 3 to have a very easy time of it).

So, the Computer Model number will just designate the Short range of the sensor.


#2 - That the typical sensor quality for Passive Array's be Routine quality (base 6+).

That'll give a 2+ (automatic, barring penalty DMs) roll required in the ship's hex (Close range).

It'll give a 4+ roll one hex out at Short range (given that the ship is using a Model 1 computer). And, it'll make for a 6+ roll on most detection tasks.


Do you think the following is unreasonalbe for a Type A Free Trader?

200 Ton Type A Free Trader
PP-A
Comp-1
Routine Class I Passive Sensor Array

Sensor roll--

2+ ... in same hex
4+ ... in one hex around the ship
6+ ... 2-10 hexes from the ship
8+ ... 11-15 hexes from the ship
9+ ... 16 hexes from the ship
10+ ... 17 hexes from the ship
11+ ... 18 hexes from the ship
12+ ... 19 hexes from the ship


I've removed the Computer model number as a DM on the sensor roll, but the Sensor Operator's skill will apply.

The Sensor Ops skill will be Navigation minus one (Nav skill at one level lower). So, if you've got a good Nav person (say, Nav-3), he can put a pretty good DM on your sensor roll.

Do those ranges and numbers above look reasonable for the Passive Sensors of a typical merchant vessel?


For contrast, using the same rules and thought processes as above, the Type T Patrol Cruiser would look like this...

400 Ton Type T Patrol Cruiser
PP - H
Comp - 3
Routine Class IV Passive Sensor Array

Sensor roll--

2+ ... in same hex.
4+ ... in 1-3 hexes from ship.
6+ ... 4-17 hexes from ship.
8+ ... 18-60 hexes from ship.
9+ ... 61 hexes from ship.
10+ ... 62 hexes from ship.
11+ ... 63 hexes from ship.
12+ ... 64 hexes from ship.


We're just talking about Passive sensors here.

What do you think about that?

 

[Supplement Four]

--UPDATE--

I'm thinking this--

#1 - That the Computer Model number can't be a DM on the sensor roll. (I can't have a +9 on that roll unless I want Model 9's...and anything over Model 3 to have a very easy time of it).

So, the Computer Model number will just designate the Short range of the sensor.


#2 - That the typical sensor quality for Passive Array's be Routine quality (base 6+).

That'll give a 2+ (automatic, barring penalty DMs) roll required in the ship's hex (Close range).

It'll give a 4+ roll one hex out at Short range (given that the ship is using a Model 1 computer). And, it'll make for a 6+ roll on most detection tasks.


Do you think the following is unreasonalbe for a Type A Free Trader?

200 Ton Type A Free Trader
PP-A
Comp-1
Routine Class I Passive Sensor Array

Sensor roll--

2+ ... in same hex
4+ ... in one hex around the ship
6+ ... 2-10 hexes from the ship
8+ ... 11-15 hexes from the ship
9+ ... 16 hexes from the ship
10+ ... 17 hexes from the ship
11+ ... 18 hexes from the ship
12+ ... 19 hexes from the ship


I've removed the Computer model number as a DM on the sensor roll, but the Sensor Operator's skill will apply.

The Sensor Ops skill will be Navigation minus one (Nav skill at one level lower). So, if you've got a good Nav person (say, Nav-3), he can put a pretty good DM on your sensor roll.

Do those ranges and numbers above look reasonable for the Passive Sensors of a typical merchant vessel?


For contrast, using the same rules and thought processes as above, the Type T Patrol Cruiser would look like this...

400 Ton Type T Patrol Cruiser
PP - H
Comp - 3
Routine Class IV Passive Sensor Array

Sensor roll--

2+ ... in same hex.
4+ ... in 1-3 hexes from ship.
6+ ... 4-17 hexes from ship.
8+ ... 18-60 hexes from ship.
9+ ... 61 hexes from ship.
10+ ... 62 hexes from ship.
11+ ... 63 hexes from ship.
12+ ... 64 hexes from ship.


We're just talking about Passive sensors here.

What do you think about that?

 

[Supplement Four]

Originally posted by BillDowns:
May I pose a couple of things, WJP?

Absolutely.

That's why I posted this here instead of just scratching it on some think paper, mumbling to myself, as I work on it.

Input.

Your thoughts are welcome.

What is the reasoning for using the power plant size for determining the split between the 3rd and 4th bands?

I was looking to keep things simple and use data already generated in CT for a ship.

Without even creating sensor data, I can look at a CT ship, see it's PP code, and know what the probable roll for sensors is going to be.

For example, a Free Trader has a PowerPlant A. I know, just from that, that, at 10 hexes or less, the Passive roll to detect is going to be 6+.

If that Free Trader has a Model 1 computer, I know that, automatically, that the passive rolls are: 2+ in same hex, 4+ one hex out, and 6+ 2-10 hexes, and 8+ at 11-15 hexes.

I just need to see the PP and the Model number of the ship, and I've basically got all I need, at a glance, to make a sensor roll for that ship.

That's what these rules are all about--implementing simple sensor rules for use with the Book 2 Space Combat system.

From a game-logic point of view, I'm thinking that larger powerplants provide more power to ships' systems.

Some RL sensor systems are power hogs, so I'm thinking that buying a bigger powerplant when building your ship brings with it upgraded systems that the bigger powerplant can support.

The game-effect is that ship's with bigger powerplants will get a litte bit of an edge over ships with smaller power plants.

For example:

The Type A Free Trader would have sensor stats I just mentioned above--

Range 0: 2+
Range 1: 4+
Range 2-10: 6+
Range 11-15: 8+
Range 16: 9+
Range 17: 10+
Range 18: 11+
Range 19: 12+


Now, compare that with a Type R Subsidized Merchant (also a M-1, J-1 vessel).

Range 0: 2+
Range 1: 4+
Range 2-12: 6+
Range 13-15: 8+
Range 16: 9+
Range 17: 10+
Range 18: 11+
Range 19: 12+


See the difference at the Medium and Long range categories? The Type R has a little bigger powerplant (but that pp also has to power a ship that is twice the size of the Type A), and at the most likely detection range (Medium range), the Type R has a little bit of an edge over the Type A.

So, that's my thinking in using the PP in these figurings.

 

[Supplement Four]

Originally posted by BillDowns:
May I pose a couple of things, WJP?

Absolutely.

That's why I posted this here instead of just scratching it on some think paper, mumbling to myself, as I work on it.

Input.

Your thoughts are welcome.

What is the reasoning for using the power plant size for determining the split between the 3rd and 4th bands?

I was looking to keep things simple and use data already generated in CT for a ship.

Without even creating sensor data, I can look at a CT ship, see it's PP code, and know what the probable roll for sensors is going to be.

For example, a Free Trader has a PowerPlant A. I know, just from that, that, at 10 hexes or less, the Passive roll to detect is going to be 6+.

If that Free Trader has a Model 1 computer, I know that, automatically, that the passive rolls are: 2+ in same hex, 4+ one hex out, and 6+ 2-10 hexes, and 8+ at 11-15 hexes.

I just need to see the PP and the Model number of the ship, and I've basically got all I need, at a glance, to make a sensor roll for that ship.

That's what these rules are all about--implementing simple sensor rules for use with the Book 2 Space Combat system.

From a game-logic point of view, I'm thinking that larger powerplants provide more power to ships' systems.

Some RL sensor systems are power hogs, so I'm thinking that buying a bigger powerplant when building your ship brings with it upgraded systems that the bigger powerplant can support.

The game-effect is that ship's with bigger powerplants will get a litte bit of an edge over ships with smaller power plants.

For example:

The Type A Free Trader would have sensor stats I just mentioned above--

Range 0: 2+
Range 1: 4+
Range 2-10: 6+
Range 11-15: 8+
Range 16: 9+
Range 17: 10+
Range 18: 11+
Range 19: 12+


Now, compare that with a Type R Subsidized Merchant (also a M-1, J-1 vessel).

Range 0: 2+
Range 1: 4+
Range 2-12: 6+
Range 13-15: 8+
Range 16: 9+
Range 17: 10+
Range 18: 11+
Range 19: 12+


See the difference at the Medium and Long range categories? The Type R has a little bigger powerplant (but that pp also has to power a ship that is twice the size of the Type A), and at the most likely detection range (Medium range), the Type R has a little bit of an edge over the Type A.

So, that's my thinking in using the PP in these figurings.

 

[Supplement Four]

Originally posted by BillDowns:
IMO, active sensors should either have a much shorter range than passive, or - my preference - a fixed range for the class, since they send out a signal and have to receive an "echo".

I'm of that opinion too, if only that some of the sensors that have popped up in other versions of traveller (MT, TNE) have shown active sensors to have something like a half to a third of the range of passive sensors.

But...

There's two problems I can see with that line of thinking.

--1-- One is that Sig (I think it was Sig) has made very good arguments that Active sensors can have the same amount of range that Passive sensors do--sometimes even more range.

For example, an electronically enhanced telephoto lens is part of a typical Passive sensor package....but this is a type of passive sensor with limited range--probably more limited in range than your everyday RADAR (active sensor).


--2-- The second problem in limiting range to the Active sensors is...what if the Passive sensors detect something out at 17 hexes (referring to the dice rolls I note above with the Type R and the Type A)?

How would Active sensors be used to lock onto that bogey at 170,000 km if the range of the Active sensors was only 100,000 (and there is no way to roll a 17 on 2D).


So...

That has lead me to this type of thinking.

Active and Passive sensors on a ship will have the same range...but Active sensors will probably have a higher die roll than Passive sensors for any given range.

So, if Passive sensors detect a bogey out at 11 bands (an 8+ roll would be needed with a Type A), then the Active sensors would require a 10+ roll at that range.

Or, something like that.

I've nailed down the typical Passive sensor to be of Routine quality. I haven't quite nailed down what I think a typical Active sensor's quality will be yet.

But, you get the idea.

Use of active sensors also ought to extend the passive detection range to it's range.

It will.

I haven't gotten into DMs yet, but a target "going active" will provide the sensing ship with a bonus DM--in effect, extending the sensor's range by making the bogey easier to detect.

 

[Supplement Four]

Originally posted by BillDowns:
IMO, active sensors should either have a much shorter range than passive, or - my preference - a fixed range for the class, since they send out a signal and have to receive an "echo".

I'm of that opinion too, if only that some of the sensors that have popped up in other versions of traveller (MT, TNE) have shown active sensors to have something like a half to a third of the range of passive sensors.

But...

There's two problems I can see with that line of thinking.

--1-- One is that Sig (I think it was Sig) has made very good arguments that Active sensors can have the same amount of range that Passive sensors do--sometimes even more range.

For example, an electronically enhanced telephoto lens is part of a typical Passive sensor package....but this is a type of passive sensor with limited range--probably more limited in range than your everyday RADAR (active sensor).


--2-- The second problem in limiting range to the Active sensors is...what if the Passive sensors detect something out at 17 hexes (referring to the dice rolls I note above with the Type R and the Type A)?

How would Active sensors be used to lock onto that bogey at 170,000 km if the range of the Active sensors was only 100,000 (and there is no way to roll a 17 on 2D).


So...

That has lead me to this type of thinking.

Active and Passive sensors on a ship will have the same range...but Active sensors will probably have a higher die roll than Passive sensors for any given range.

So, if Passive sensors detect a bogey out at 11 bands (an 8+ roll would be needed with a Type A), then the Active sensors would require a 10+ roll at that range.

Or, something like that.

I've nailed down the typical Passive sensor to be of Routine quality. I haven't quite nailed down what I think a typical Active sensor's quality will be yet.

But, you get the idea.

Use of active sensors also ought to extend the passive detection range to it's range.

It will.

I haven't gotten into DMs yet, but a target "going active" will provide the sensing ship with a bonus DM--in effect, extending the sensor's range by making the bogey easier to detect.

 

[BillDowns]

Well, that's not RW.

Example: Patrol cruiser pulses from range 60. That's 2 seconds to hit the target, and 2 more to get back. In those 2 seconds, any military ship could get off a fairly accurate missle salvo, or possibly a long-range laser salvo before the Patrol Cruiser would even know there's a target out there. That's one area David Weber has hit right-on in the Harrington novels.

 

[BillDowns]

Well, that's not RW.

Example: Patrol cruiser pulses from range 60. That's 2 seconds to hit the target, and 2 more to get back. In those 2 seconds, any military ship could get off a fairly accurate missle salvo, or possibly a long-range laser salvo before the Patrol Cruiser would even know there's a target out there. That's one area David Weber has hit right-on in the Harrington novels.

 

[Supplement Four]

Originally posted by BillDowns:
Example: Patrol cruiser pulses from range 60. That's 2 seconds to hit the target, and 2 more to get back. In those 2 seconds, any military ship could get off a fairly accurate missle salvo, or possibly a long-range laser salvo before the Patrol Cruiser would even know there's a target out there.

So, given my question earlier in the thread, about if it were possible for a missile to hit a target ship without the target ship detecting the missile before it blows...

...your answer is YES!

I don't know if you read my other thread (the one about "Masters of their own destiny"), but in that scenario, I've got a Type AH Hercules and a missile speeding towards it.

I'm looking at these sensor rules, and Book 2 space combat, and here's what I see...

(You tell me if you think this is a likely scenario.)


Ambush ship is grappled to an asteroid.

Big 5000 ton-er Herc plowing its way through the asteroid belt.

Space Combat Round 1:

Ambush ship fires nuke missile in the Ordnance Launch phase, but missile doesn't actually move until the next intruder movement phase.

Sensor rolls are made in the Movement phase, so I make a roll for the Type AH. It rolls a 4.

The Herc's Passive sensor profile, using the rules I'm developing here, would be--

Range 0: 2+
Range 1-2: 4+
Range 3-30: 6+
Range 31-45: 8+
Range 46: 9+
Range 47: 10+
Range 48: 11+
Range 49: 12+

The range to the missile, at this point, is 15 hexes. The Type AH needs a 6+ to detect. He only rolled a 4.

(And, I haven't added in DMs yet...like a -2DM for missile size, and a -2DM from asteroid interference.)

So, the Type AH didn't detect the missile launch.

The Herc then proceeds with the movement phase, moving 3 hexes (closing range with the missile, now at 12 hexes).

So now, we're at the top of Space Combat Round 2, in the ambush ship's movement phase...the missile moves.

Since the Herc didn't detect the missile in its last sensor phase (movement phase), there is no Laser Return fire phase for the Herc (I would allow this if the missile had been detected).

The missile is a 6G6 missile, coverng the 12 hexes needed to the Herc, and then the missile will blow in the ambush ship's Ordnance Launch phase.

What about that?

Plausible?

Or, do you think it's too easy to skirt sensors and whap ships with missiles using these sensor rules?

(Of course, the Herc did roll a stinkin' 4 on his detect roll...)

That's one area David Weber has hit right-on in the Harrington novels.

You know...I'm just starting Book 3 tonight!

Good stuff.

 

[Supplement Four]

Originally posted by BillDowns:
Example: Patrol cruiser pulses from range 60. That's 2 seconds to hit the target, and 2 more to get back. In those 2 seconds, any military ship could get off a fairly accurate missle salvo, or possibly a long-range laser salvo before the Patrol Cruiser would even know there's a target out there.

So, given my question earlier in the thread, about if it were possible for a missile to hit a target ship without the target ship detecting the missile before it blows...

...your answer is YES!

I don't know if you read my other thread (the one about "Masters of their own destiny"), but in that scenario, I've got a Type AH Hercules and a missile speeding towards it.

I'm looking at these sensor rules, and Book 2 space combat, and here's what I see...

(You tell me if you think this is a likely scenario.)


Ambush ship is grappled to an asteroid.

Big 5000 ton-er Herc plowing its way through the asteroid belt.

Space Combat Round 1:

Ambush ship fires nuke missile in the Ordnance Launch phase, but missile doesn't actually move until the next intruder movement phase.

Sensor rolls are made in the Movement phase, so I make a roll for the Type AH. It rolls a 4.

The Herc's Passive sensor profile, using the rules I'm developing here, would be--

Range 0: 2+
Range 1-2: 4+
Range 3-30: 6+
Range 31-45: 8+
Range 46: 9+
Range 47: 10+
Range 48: 11+
Range 49: 12+

The range to the missile, at this point, is 15 hexes. The Type AH needs a 6+ to detect. He only rolled a 4.

(And, I haven't added in DMs yet...like a -2DM for missile size, and a -2DM from asteroid interference.)

So, the Type AH didn't detect the missile launch.

The Herc then proceeds with the movement phase, moving 3 hexes (closing range with the missile, now at 12 hexes).

So now, we're at the top of Space Combat Round 2, in the ambush ship's movement phase...the missile moves.

Since the Herc didn't detect the missile in its last sensor phase (movement phase), there is no Laser Return fire phase for the Herc (I would allow this if the missile had been detected).

The missile is a 6G6 missile, coverng the 12 hexes needed to the Herc, and then the missile will blow in the ambush ship's Ordnance Launch phase.

What about that?

Plausible?

Or, do you think it's too easy to skirt sensors and whap ships with missiles using these sensor rules?

(Of course, the Herc did roll a stinkin' 4 on his detect roll...)

That's one area David Weber has hit right-on in the Harrington novels.

You know...I'm just starting Book 3 tonight!

Good stuff.

 

[Supplement Four]

Another ponderable, for those of you enjoying these ponderings...

--1-- Should a bogey that's been detected on ship's sensors stay detected automatically?

What I'm getting at is--if a sensor roll turns up a bogey during space combat, should a new roll be required to maintain the detection/lock each game round (maintaining the contact/detection/lock over 1000 seconds)?


--2-- Or, if something is detected, should it just remain detected--no roll required to "maintain" the lock over time? It will stay detected as long as conditions remain the same...that (A) the bogey stays in detection range (90 hexes in CT), and (B) doesn't confuse sensors with jamming or jamming missiles or something like that.


I'm more of the opinion expressed in #2, but I could be swayed the other way. I thinking that #2 is more conducive to Book 2 space combat as well in that once an enemy is detected, the sensor rolls will take a back seat to the standard CT fighting--and not even be needed again unless detection is lost somehow (jamming, out of range, goes behind a planet, whatever).

Thoughts?

 

[Supplement Four]

Another ponderable, for those of you enjoying these ponderings...

--1-- Should a bogey that's been detected on ship's sensors stay detected automatically?

What I'm getting at is--if a sensor roll turns up a bogey during space combat, should a new roll be required to maintain the detection/lock each game round (maintaining the contact/detection/lock over 1000 seconds)?


--2-- Or, if something is detected, should it just remain detected--no roll required to "maintain" the lock over time? It will stay detected as long as conditions remain the same...that (A) the bogey stays in detection range (90 hexes in CT), and (B) doesn't confuse sensors with jamming or jamming missiles or something like that.


I'm more of the opinion expressed in #2, but I could be swayed the other way. I thinking that #2 is more conducive to Book 2 space combat as well in that once an enemy is detected, the sensor rolls will take a back seat to the standard CT fighting--and not even be needed again unless detection is lost somehow (jamming, out of range, goes behind a planet, whatever).

Thoughts?

 

[Ptah]

In the above missile example, maybe that's why you need a CSP (combat space patrol) .

On rules, game-play IMHO strongly argues for #2, no reroll. The situation also argues for it especially once a ship starts firing it should be automatically detectable unless your sensors have been burned off.

 

[Ptah]

In the above missile example, maybe that's why you need a CSP (combat space patrol) .

On rules, game-play IMHO strongly argues for #2, no reroll. The situation also argues for it especially once a ship starts firing it should be automatically detectable unless your sensors have been burned off.

 

[Plankowner]

In your combat scenario above, HOW did the 400 Ton ship detect/lock onto the Herc? You are requiring the 400Ton ship to have have some pretty good sensors, did you consider that?

I would consider that an object under accelleration (ship or missile) would get a pretty good +DM on Passive Sensors. The thrust of the engine will put out a LOT of IR and other types of radiation that should make it pretty easy to detect.

A comment about active sensors: Since active sensors send out energy and measure the echo, the passive detection range for another ship should be TWICE the active range. Think about it, Active Sensors need some minimum signal strength to detect the echo. That same signal strength will exist at 2X Active Range out in space where the signal didn't bounce. Bill's idea of 1/2 of your Passive Range for your Active Range makes sense when you think of it like that.

 

[Plankowner]

In your combat scenario above, HOW did the 400 Ton ship detect/lock onto the Herc? You are requiring the 400Ton ship to have have some pretty good sensors, did you consider that?

I would consider that an object under accelleration (ship or missile) would get a pretty good +DM on Passive Sensors. The thrust of the engine will put out a LOT of IR and other types of radiation that should make it pretty easy to detect.

A comment about active sensors: Since active sensors send out energy and measure the echo, the passive detection range for another ship should be TWICE the active range. Think about it, Active Sensors need some minimum signal strength to detect the echo. That same signal strength will exist at 2X Active Range out in space where the signal didn't bounce. Bill's idea of 1/2 of your Passive Range for your Active Range makes sense when you think of it like that.

 

[parmasson]

Also could a 200 ton ship with a 6G be more easly picked up than a 200 ton ship with a 1G accl?

 

[parmasson]

Also could a 200 ton ship with a 6G be more easly picked up than a 200 ton ship with a 1G accl?