Sensor Ranges in CT

[Supplement Four]

Originally posted by Sigg Oddra:
The ranges above are for active scans. Passive scans have a quarter of the above range.

Hey Sig...

Shouldn't the passive sensors have a longer range than active scans?

Like the Hubble telescope (range on that thing is incredible), or even the ranges used in the various Traveller editions.

I just happen to have TNE here on my desk (I was looking at their sensor rules earlier), and I notice that the Far Trader's Passive EMS Short Range is 30,000 km while the ship's Active EMS Short Range is only 3,000 km.

I always thought passive sensors have greater range than active sensors.

 

[Supplement Four]

Originally posted by Sigg Oddra:
The ranges above are for active scans. Passive scans have a quarter of the above range.

Hey Sig...

Shouldn't the passive sensors have a longer range than active scans?

Like the Hubble telescope (range on that thing is incredible), or even the ranges used in the various Traveller editions.

I just happen to have TNE here on my desk (I was looking at their sensor rules earlier), and I notice that the Far Trader's Passive EMS Short Range is 30,000 km while the ship's Active EMS Short Range is only 3,000 km.

I always thought passive sensors have greater range than active sensors.

 

[Supplement Four]

Sig...

BTW, I think I've got a simpler way to handle sensors in CT.

I haven't got it all worked out yet, but I'll post it when finish it (it's almost done).


===============================
===============================


I'll give you a taste of what I'm thinking. You might like the system (I'll use UGM, of course).

A sensor scan will be a Standard Difficulty UGM roll.

2D +mods for 8+


All other factors will be modifiers to this roll. (working all these out is what I'm working on).

For example, a ship's sensor range is a function of it's PowerPlant Letter (I got that from what you posted, then tweaked it).

Consider the letter code for a ship's PowerPlant to be standard Traveller hexidecimal notation (So, A = 10, B = 11, C = 12, etc...)

Use this as a simple DM on the sensor task. (So, a Free Trader, with PP A, would roll sensor tasks at 2D +10 for 8+).

Then, subtract the range of the target (in standard LLB 1 range bands...each range band = 10,000 km) from the roll.

.....What does this give you?.....

Just by knowing the ship's PP code, we've got a sensor task.

Very simple.

Simple is what I like (and I know you like simple too).


If you've got a Free Trader (PP A), and there is a bogey at 130,000 km, then that ship will be detected on a 2D throw of 11+.

2D +10 -13 for 8+

...which translates to...

2D for 11+.

============================
============================


I've looked at the military vessels and the civilian vessels in CT, and this very simple method will provide (near) the results listed under the CT detection rules.

For example, a Mercenary Cruiser (I'm assuming this ship has military grade sensors) has PP M.

Sensor tasks for that ship will be:

2D +21 for 8+.

CT rules specify that military grade sensors can detect out to about 60,000 km.

This is the part I'm working on.

I'm thinking of military grade sensors having a DM of -1 for every 3 range bands instead of every one for active sensors.

60,000 / 3 = 20,000

Which would make our sensor roll:

2D +21 -20 for 8+.

Detection would occur on a roll of 2D for 7+.

===========================


I just need to work out the bugs on this system, but I think I like it.

We can adust the range DM (like I did above for military sensors) if you want the added complexity of having Passive and Active sensors.

And, we can add in other DMs for skill, computer, target size, etc.

I've got ideas for this--I just wanted to show you the core of the sensor system.

I like it's simplicity!

 

[Supplement Four]

Sig...

BTW, I think I've got a simpler way to handle sensors in CT.

I haven't got it all worked out yet, but I'll post it when finish it (it's almost done).


===============================
===============================


I'll give you a taste of what I'm thinking. You might like the system (I'll use UGM, of course).

A sensor scan will be a Standard Difficulty UGM roll.

2D +mods for 8+


All other factors will be modifiers to this roll. (working all these out is what I'm working on).

For example, a ship's sensor range is a function of it's PowerPlant Letter (I got that from what you posted, then tweaked it).

Consider the letter code for a ship's PowerPlant to be standard Traveller hexidecimal notation (So, A = 10, B = 11, C = 12, etc...)

Use this as a simple DM on the sensor task. (So, a Free Trader, with PP A, would roll sensor tasks at 2D +10 for 8+).

Then, subtract the range of the target (in standard LLB 1 range bands...each range band = 10,000 km) from the roll.

.....What does this give you?.....

Just by knowing the ship's PP code, we've got a sensor task.

Very simple.

Simple is what I like (and I know you like simple too).


If you've got a Free Trader (PP A), and there is a bogey at 130,000 km, then that ship will be detected on a 2D throw of 11+.

2D +10 -13 for 8+

...which translates to...

2D for 11+.

============================
============================


I've looked at the military vessels and the civilian vessels in CT, and this very simple method will provide (near) the results listed under the CT detection rules.

For example, a Mercenary Cruiser (I'm assuming this ship has military grade sensors) has PP M.

Sensor tasks for that ship will be:

2D +21 for 8+.

CT rules specify that military grade sensors can detect out to about 60,000 km.

This is the part I'm working on.

I'm thinking of military grade sensors having a DM of -1 for every 3 range bands instead of every one for active sensors.

60,000 / 3 = 20,000

Which would make our sensor roll:

2D +21 -20 for 8+.

Detection would occur on a roll of 2D for 7+.

===========================


I just need to work out the bugs on this system, but I think I like it.

We can adust the range DM (like I did above for military sensors) if you want the added complexity of having Passive and Active sensors.

And, we can add in other DMs for skill, computer, target size, etc.

I've got ideas for this--I just wanted to show you the core of the sensor system.

I like it's simplicity!

 

[Supplement Four]

One more thing, Sig...

I'm also thinking this:

The ship's TL can be used in place of a character's stat (probably EDU) when making sensor rolls. Players can use whichever is higher.

If you're on a TL 10 ship, but your Navigator is EDU-12, then the Navigator will want to use his own education.

But, those Navigators with EDU 9 or less will probably want to rely on the ship's analysis of sensor data.


In the same fashion, I think the ship's computer number can be used in place of sensor skill (Sensor Ops is Navigation skill minus one). So, those Navigation-1 characters out there will probably want to use the ship's computer in place of their own Sensor Ops-0 skill.


And...

Whenever the bridge is not manned (maybe on long inter-planetary journeys...or when there is only one character with appropriate skill...he's got to get some rest some time), the ship can conduct passive scans by itself.

I figure the passive scanners on a spacecraft are always "on".

So, in order to make a roll like this when a character isn't involved (the GM may make this one in secret), he'd make a Standard Difficulty UGM task roll, but use the ship's TL as the "stat" and the ship's computer number as the "skill" on this task.

Pretty cool, eh?


I'll try to get all the ins-and-outs of this system figured out, and when I do, I'll post it.

 

[Supplement Four]

One more thing, Sig...

I'm also thinking this:

The ship's TL can be used in place of a character's stat (probably EDU) when making sensor rolls. Players can use whichever is higher.

If you're on a TL 10 ship, but your Navigator is EDU-12, then the Navigator will want to use his own education.

But, those Navigators with EDU 9 or less will probably want to rely on the ship's analysis of sensor data.


In the same fashion, I think the ship's computer number can be used in place of sensor skill (Sensor Ops is Navigation skill minus one). So, those Navigation-1 characters out there will probably want to use the ship's computer in place of their own Sensor Ops-0 skill.


And...

Whenever the bridge is not manned (maybe on long inter-planetary journeys...or when there is only one character with appropriate skill...he's got to get some rest some time), the ship can conduct passive scans by itself.

I figure the passive scanners on a spacecraft are always "on".

So, in order to make a roll like this when a character isn't involved (the GM may make this one in secret), he'd make a Standard Difficulty UGM task roll, but use the ship's TL as the "stat" and the ship's computer number as the "skill" on this task.

Pretty cool, eh?


I'll try to get all the ins-and-outs of this system figured out, and when I do, I'll post it.

 

[Supplement Four]

I'm thinking that sensor sensitivity will be recorded something like this:

Active EMS 1

or

Active EMS 1/2

or

Active EMS 2


What the "sensitivity" means is how many range bands to count before subtracting -1DM from your sensors throw.

"1" would mean -1DM for each range band to target.

"2" would mean -1DM for every two range bands to target.

"1/2" would mean -2DM for every range band to target.


=============================

I'm thinking that civilian passive sensors have a sensitivity of 1, while military grade sensors have a sensitivity of 3.

Active sensors will probably have fractional sensitivity.

There can be "improved" or "advanced" sensors (very expensive) on the civilian market (for nobles, powerful businessmen, and other rich individuals) that are available from only high-tech worlds with sensitivty 2.

 

[Supplement Four]

I'm thinking that sensor sensitivity will be recorded something like this:

Active EMS 1

or

Active EMS 1/2

or

Active EMS 2


What the "sensitivity" means is how many range bands to count before subtracting -1DM from your sensors throw.

"1" would mean -1DM for each range band to target.

"2" would mean -1DM for every two range bands to target.

"1/2" would mean -2DM for every range band to target.


=============================

I'm thinking that civilian passive sensors have a sensitivity of 1, while military grade sensors have a sensitivity of 3.

Active sensors will probably have fractional sensitivity.

There can be "improved" or "advanced" sensors (very expensive) on the civilian market (for nobles, powerful businessmen, and other rich individuals) that are available from only high-tech worlds with sensitivty 2.

 

[Supplement Four]

Using this system, all you really need to know is the ship's PowerPlant value and the range to the target.

If you know those two things, you can do a sensor check without a lot of fuss.


For right now, until I work this all out, let's say all civilian ships have sensitivty 1 while military vessles have sensitivty 3.


==============================================


Example 1 (Civilian Vessel).

The Subsidized Liner has PowerPlant J.

Sensor task for this ship:

2D +18 for 8+.

The GM knows that there is a corsair lurking at 120,000 km distant from the liner.

The sensor task to detect the corsair is:

2D +18 -12 for 8+

Which translates to: (2D +4 for 8+)

2D for 4+.

==============================================


Example 2 (Military Vessel)

A Type T Patrol Cruiser has PowerPlant H.

Sensor tasks for this ship are:

2D +17 for 8+


The Patrol Cruiser is 600,000 km from that corsair lurking to attack the liner above.

The task for this patrol cruiser to detect the corsair is:

2D +17 -20 for 8+.

Which translates to: (2D -3 for 8+)

2D for 11+.


------------
Where'd I get the "-20"? It's the ship's military sensitivity.

[(Distance / 3) / 10,000]

600,000 / 3 = 200,000 (sensitivity of military sensors is 3)

200,000 / 10,000 = 20 (-1DM per 3 range bands, for a total of -20 on the sensor roll).

 

[Supplement Four]

Using this system, all you really need to know is the ship's PowerPlant value and the range to the target.

If you know those two things, you can do a sensor check without a lot of fuss.


For right now, until I work this all out, let's say all civilian ships have sensitivty 1 while military vessles have sensitivty 3.


==============================================


Example 1 (Civilian Vessel).

The Subsidized Liner has PowerPlant J.

Sensor task for this ship:

2D +18 for 8+.

The GM knows that there is a corsair lurking at 120,000 km distant from the liner.

The sensor task to detect the corsair is:

2D +18 -12 for 8+

Which translates to: (2D +4 for 8+)

2D for 4+.

==============================================


Example 2 (Military Vessel)

A Type T Patrol Cruiser has PowerPlant H.

Sensor tasks for this ship are:

2D +17 for 8+


The Patrol Cruiser is 600,000 km from that corsair lurking to attack the liner above.

The task for this patrol cruiser to detect the corsair is:

2D +17 -20 for 8+.

Which translates to: (2D -3 for 8+)

2D for 11+.


------------
Where'd I get the "-20"? It's the ship's military sensitivity.

[(Distance / 3) / 10,000]

600,000 / 3 = 200,000 (sensitivity of military sensors is 3)

200,000 / 10,000 = 20 (-1DM per 3 range bands, for a total of -20 on the sensor roll).

 

[Supplement Four]

I'm going to go play with sensitivity numbers now, to come up with the right "mix" for civilian and military sensors, and active and passive sensors.

I'll also look at DMs that should be applied to the sensor roll.

Target Size (probably use size DMs from High Guard).

Skill (or Computer number - player's choice)

I can think of a few more DMs that might be useful (whether the drives are pointed towards the detecting ship--sand clouds vs LADAR--a few other things).

Can anybody think of anything else that need to be included in these rules? I know I need a jamming rule, but I've got an idea for that too.

When I get something worked up, I'll post it, and we can all go over it to see if there are any bugs that need to be fixed.

 

[Supplement Four]

I'm going to go play with sensitivity numbers now, to come up with the right "mix" for civilian and military sensors, and active and passive sensors.

I'll also look at DMs that should be applied to the sensor roll.

Target Size (probably use size DMs from High Guard).

Skill (or Computer number - player's choice)

I can think of a few more DMs that might be useful (whether the drives are pointed towards the detecting ship--sand clouds vs LADAR--a few other things).

Can anybody think of anything else that need to be included in these rules? I know I need a jamming rule, but I've got an idea for that too.

When I get something worked up, I'll post it, and we can all go over it to see if there are any bugs that need to be fixed.

 

[Merxiless]

You'll also need to include for passive background masking by stars, and other radio sources like very large gas giants.

If a target ship is sunward of the passive sensor, it'll be tougher to pick it out of the background noise, especially if the sun is closer.

But, I'd think thgat visually, you might be able to pick it up easier, like a sunspot, only it's moving.

Active shoudn't have this problem.

Also for active densitometer types of scans, you might want to add in target ID modifiers for nearby asteroids, and comets, as false contacts, maybe space junk, too.

Neutrino scans will easily detect the difference between a rock and a powerplant-bearing ship.

 

[Merxiless]

You'll also need to include for passive background masking by stars, and other radio sources like very large gas giants.

If a target ship is sunward of the passive sensor, it'll be tougher to pick it out of the background noise, especially if the sun is closer.

But, I'd think thgat visually, you might be able to pick it up easier, like a sunspot, only it's moving.

Active shoudn't have this problem.

Also for active densitometer types of scans, you might want to add in target ID modifiers for nearby asteroids, and comets, as false contacts, maybe space junk, too.

Neutrino scans will easily detect the difference between a rock and a powerplant-bearing ship.

 

[Supplement Four]

I've got some rules sketched out. I'll post'em in another, new, (it's own) thread to get more input.

We can take it from there.

 

[Supplement Four]

I've got some rules sketched out. I'll post'em in another, new, (it's own) thread to get more input.

We can take it from there.

 

[mike wightman]

Originally posted by WJP:
</font><blockquote>quote:</font><hr />Originally posted by Sigg Oddra:
The ranges above are for active scans. Passive scans have a quarter of the above range.

Hey Sig...

Shouldn't the passive sensors have a longer range than active scans?

Like the Hubble telescope (range on that thing is incredible), or even the ranges used in the various Traveller editions.

I just happen to have TNE here on my desk (I was looking at their sensor rules earlier), and I notice that the Far Trader's Passive EMS Short Range is 30,000 km while the ship's Active EMS Short Range is only 3,000 km.

I always thought passive sensors have greater range than active sensors. </font>[/QUOTE]Hi WJP (what does that stand for by the way?),

I can understand where you are coming from with this.

Therules I posted are quite an old idea, and are probably due for an overhaul

Consider this though.

Why didn't the Hubble notice the moons around Pluto
Why didn't Hubble notice the new Kuiper belt planets?

Hubble doesn't scan, it points to a very small part of the night sky and looks at thet very narrow section, but it does so in very high resolution.
How long does it take Hubble to gather the info. to make an image?

Why, in the real world, do navy ships use radar instead of mast mounted cameras to guide their weapons (althigh they probably do have cameras up there too).


The numbers for my active/passive ranges are based on the Star Cruiser game, and they are for obtaining a firing solution, not just "noticing something is out there". All objects on the table are denoted by blank markers until they are identified by a sensor scan.


Note that a ship going active will be detected by the passive sensors of a ship at a much greater range than those passive sensors would usually give a sensor resolution.

 

[mike wightman]

Originally posted by WJP:
</font><blockquote>quote:</font><hr />Originally posted by Sigg Oddra:
The ranges above are for active scans. Passive scans have a quarter of the above range.

Hey Sig...

Shouldn't the passive sensors have a longer range than active scans?

Like the Hubble telescope (range on that thing is incredible), or even the ranges used in the various Traveller editions.

I just happen to have TNE here on my desk (I was looking at their sensor rules earlier), and I notice that the Far Trader's Passive EMS Short Range is 30,000 km while the ship's Active EMS Short Range is only 3,000 km.

I always thought passive sensors have greater range than active sensors. </font>[/QUOTE]Hi WJP (what does that stand for by the way?),

I can understand where you are coming from with this.

Therules I posted are quite an old idea, and are probably due for an overhaul

Consider this though.

Why didn't the Hubble notice the moons around Pluto
Why didn't Hubble notice the new Kuiper belt planets?

Hubble doesn't scan, it points to a very small part of the night sky and looks at thet very narrow section, but it does so in very high resolution.
How long does it take Hubble to gather the info. to make an image?

Why, in the real world, do navy ships use radar instead of mast mounted cameras to guide their weapons (althigh they probably do have cameras up there too).


The numbers for my active/passive ranges are based on the Star Cruiser game, and they are for obtaining a firing solution, not just "noticing something is out there". All objects on the table are denoted by blank markers until they are identified by a sensor scan.


Note that a ship going active will be detected by the passive sensors of a ship at a much greater range than those passive sensors would usually give a sensor resolution.

 

[Supplement Four]

Originally posted by Sigg Oddra:
Hi WJP (what does that stand for by the way?),

Walker Jane Productions. I probably shouldn't have used it--I wasn't thinking when I set up my account. It's my production company--I'm an indie filmmaker.

Why didn't the Hubble notice the moons around Pluto
Why didn't Hubble notice the new Kuiper belt planets?

(Scratches head. Squints)

Dunno.

Hubble doesn't scan, it points to a very small part of the night sky and looks at thet very narrow section, but it does so in very high resolution.

Ah-ha! So, it's a Passive Array sensor used in a Sensor Lock task--not used for Sensor Scans (saw that in some new sensor rules somewhere areound here... )

How long does it take Hubble to gather the info. to make an image?

(shrugs shoulders)

You got me.

Why, in the real world, do navy ships use radar instead of mast mounted cameras to guide their weapons (althigh they probably do have cameras up there too).

(Looks at new sensor rules...notices that Active sensors can be of higher quality and have more range than Passive sensors...or the other way around...simply by the choice of Sensor Quality...smiles)


Gotcha.

I guess I was curious about that because, it seems, Active sensors in Traveller always seem to have shorter ranges than Passive sensors.

In TNE, for example, the Far Trader has a max range of 240,000 km for it's Passive EMS Array while the Active EMS Array's max range is only 10% of that....at 24,000 km.

In MT, the same ship has a max range for it's Passive EMS Array as Interstellar (which is freakin' 2 parsecs!...something wrong there, eh?), but it's Active EMS Array max range is Far Orbit (which is 500,000 km)....I've always had a problem with MT sensor ranges, btw...but the point is that the Active sensors, again, are some factor smaller (in range) than a ship's Passive sensor range.

 

[Supplement Four]

Originally posted by Sigg Oddra:
Hi WJP (what does that stand for by the way?),

Walker Jane Productions. I probably shouldn't have used it--I wasn't thinking when I set up my account. It's my production company--I'm an indie filmmaker.

Why didn't the Hubble notice the moons around Pluto
Why didn't Hubble notice the new Kuiper belt planets?

(Scratches head. Squints)

Dunno.

Hubble doesn't scan, it points to a very small part of the night sky and looks at thet very narrow section, but it does so in very high resolution.

Ah-ha! So, it's a Passive Array sensor used in a Sensor Lock task--not used for Sensor Scans (saw that in some new sensor rules somewhere areound here... )

How long does it take Hubble to gather the info. to make an image?

(shrugs shoulders)

You got me.

Why, in the real world, do navy ships use radar instead of mast mounted cameras to guide their weapons (althigh they probably do have cameras up there too).

(Looks at new sensor rules...notices that Active sensors can be of higher quality and have more range than Passive sensors...or the other way around...simply by the choice of Sensor Quality...smiles)


Gotcha.

I guess I was curious about that because, it seems, Active sensors in Traveller always seem to have shorter ranges than Passive sensors.

In TNE, for example, the Far Trader has a max range of 240,000 km for it's Passive EMS Array while the Active EMS Array's max range is only 10% of that....at 24,000 km.

In MT, the same ship has a max range for it's Passive EMS Array as Interstellar (which is freakin' 2 parsecs!...something wrong there, eh?), but it's Active EMS Array max range is Far Orbit (which is 500,000 km)....I've always had a problem with MT sensor ranges, btw...but the point is that the Active sensors, again, are some factor smaller (in range) than a ship's Passive sensor range.