sensor rules

[vecna35]

I was wondering if someone could explain to me how long range sensors work (in game terms) and the difference with short range (in combat) sensors ,seeing extended range +1 = 100,000km. I know how one can be surprised by failing a sensor test but how do long range sensors factor into this?

[Doug Burke]

Don went into more detail on how sensors work in Starships. Might want to check there...

[vecna35]

I did check there Doug...this is why i am confused. He does not mention how this affects surprise or what data you can collect. Basically the difference between short range (which is pretty clear) and long range (I do know how far u can scan but just need to know the details it tells u and how it relates to such questions as Surprise, cloaked ships, etc)

Killerwhale do you have any thoughts on that? I have read your ESO several times and thought maybe u might have something to say.

[Tomcat]

Check out the Players Guide page 191, upper left paragraph finishes the section on Sensors:

'They can detect solid objects, gravimetric and energy phenomena, subspace emissions, thermal images, neutrino images, and varaiations or fluctuatuions within any occurence.'

That is the official word on what they can detect.

Then the Sensor bonuses talked about in the Starship Combat section also may be applied when using Long Range Sensors using Table 1.29 in the Starships book.

Like you, I have been having some issues with sensors and how they work in regards to PASSIVE versus ACTIVE - I even wrote up a HOUSE RULE for it but haven't had a chance to put it to a test. Anyway, per the Starfleet Operations Manual (SOM) there are three kind of settings - PASSIVE, INTERMITENT, and ACTIVE. The different levels of sensor radiation makes the ship easier or more difficult to detect (changes in TN), but it doesn't give good info on what can be detected at each setting.

I agree with one persons post that this is an RPG so it shouldn't get to bogged down with mechanics - it should be story driven - the crew detects what the narrator wants them to detect. Still my 'T' personality craves a little more meat and potatoes.

Anyway, here is my sensor House Rule if you want it:

[vecna35]

Hey Tomcat, would u believe me if I told you my players have been using your first pdf of emcom rules. They are good and in fact help this game out a lot. I like your new pdf...though ur first one was straight and to the point this one is good too.

How do u use long range sensors from the book starships in terms of surprise??? If someone can scan 5 lightyears away I don't see how anyone can get a surprise on each other?

I think I will now print out your emcom and add it to my collection before this site goes down

[Tomcat]

Here is what I would do to work with Surprise and sensors:

Using my Sensors House Rule lets look at an example of two ships from the Starships book - a re-fit Constitution class and a B'rel:

Sensor Rating:
CONNIE - +3/+2/+1/0/0
Sensor Operator has a +11 (all ranks and mods)

B'rel +2/+1/0/0/0
Sensor Operator has a +11 (all ranks and mods)

Let's set up our encounter with the B'rel sneaking into Fed space (not cloaked) but Running Silent (EMCON 1) and the Connie running at SOP for Under Weigh (EMCON 2). Also let's assume that they are at a distance of 20 LY - the distance of Standard Resolution Long Range scans (the maximum scan range for sensors and 1 month's travel at Warp 5).

The Sys Ops (Sensor) test for the B'rel:
TN 10 + 0 (EMCON) + 6 (Range) + 0 (Sensor Mod)= TN 16
Roll - 9+11= 20 Complete Success

The Sys Ops (Sensor) test for the Connie:
TN 10 + 10 (EMCON) + 6 (Range) + 0 (Sensor Mod)= TN 26
Roll - 8+11= 19 FAILED

As Narrator I would describe the Klingon's results as such - 'Far off in distant space, the B'rel sensors detect radiation. Is it ambient radiation from a dying star or is it a Federation ship patrolling the sector? The Klingon commander decides it is too distant to concern with and keeps on their present course. He brings his ship to Warp.' (If it were the Connie, there is nothing to tell...)

Now lets bring our situation in closer, assuming the ships have been on a course towards one another. Both ships are at Warp Factor 5, 6 Light Years away and closing (9 days distant), and now are using their Long Range Sensors set to High Resolution at EMCON 2:

The Sys Ops (Sensor) test for the B'rel:
TN 10 + 0 (EMCON) + 6 (Range) + 0 (Sensor Mod)= TN 16
Roll - 10+11= 21 Complete Success

The Sys Ops (Sensor) test for the Connie:
TN 10 + 0 (EMCON) + 6 (Range) + 0 (Sensor Mod)= TN 16
Roll - 7+11= 18 Complete Success

As Narrator I would describe the two ship's results as such - 'Sensor scans have definitely detected a ship moving at warp, picking up the object and its subspace emissions. Is the ship a freind or foe? (for the klingon: is the ship a threat or prey?) Distance is still great between them and it is now worth the time to divert course and see who is out there.'

I may even allow a TN 25 or 30 Sys Ops (Sensors) or Compuer Use (Analyze) to determine the ship type from the emission. I may give affinity bonuses for some kinds engineering, knowledge, or science. Point is they know that something is out there, just not what. As they close, it would be worth it for the B'rel to go to EMCON 1 and then to cloak making them a hole in space and gain the definite surprise on the CONNIE.

Ships have now closed to 2 LY (1 day away) and they are still traveling at warp 5, Long Range Scans still at High Resolution (EMCON 2):

The Sys Ops (Sensor) test for the B'rel:
TN 10 + 0 (EMCON) + 0 (Range) - 1 (Sensor Mod)= TN 9
Roll - 5+11= 16 Superior Success

The Sys Ops (Sensor) test for the Connie:
TN 10 + 0 (EMCON) + 0 (Range) - 2 (Sensor Mod)= TN 8
Roll - 9+11= 20 Extraordiary Success

As Narrator I would describe the two ship's results as such - 'Sensor scans are tracking a ship moving at warp 5, its mass is (SIZE ??), and class may be determined by its warp signature.

I will require a TN 15 or 20 Sys Ops (Sensors) or Compuer Use (Analyze) to determine the ship type fromthe emission. I may give affinity bonuses for some kinds engineering, knowledge, or science as well as a bonus based on Degree of Success.

The ships close that last day and come within kilometers (Long Range 100,000 KM) of each other and switch from long-range scanners to short-range and lateral scanners. The Connie stays at EMCON 2, sweeping the area for any trace of the ship while the Klingon drops out of Warp and begins Silent Running (EMCON 1) as well as cloaks.

The Sys Ops (Sensor) test for the B'rel:
TN 10 + 0 (EMCON) + 4 (Range) - 0 (Sensor Mod)= TN 14
Roll - 7+11= 18 Complete Success

The Sys Ops (Sensor) test for the Connie:
TN 20 (CLOAKED) + 10 (EMCON) + 4 (Range) - 0 (Sensor Mod)= TN 34
Roll - 4+11= 15 Disastrous Failure

As Narrator I would describe the two ship's results as such - 'The Science Officer aboard the Connie looks up to his Captain and says that the ship has disappeared completely off of scanners.' (if they know the class from the above tests, they mayknow why.)

When the Klingon uncloaks, he will have complete surprise on the CONNIE and be able to take a Free attack (or whatever the Narrator awards the player). The only problem with making his ship 'disappear so completely' is that he will need time bringing systems back on line.

Anyway, this is how I would interpret my sensor rules into using LONG RANGE SCANNERS and trying to achieve some surprise. Without the cloaking device, the B'rel may not have gotten their surprise, who knows?

[vecna35]

Thank-you very much Tomcat. I think thats the first example I have ever seen for Long Range Sensors. I can guess how a non cloacking ship can achieve surprise (running silent for 10 days or hiding behind a planet. Something like D&D where u have to hide somewhere to even achieve surprise.

How often do you allow the Long Range sensor check? 1 day? Every hour?. whats preventing PCs from scanning every min? whith short range its every round but for long range, they will surly see someone 9 days away if they scan every min. There must be some form time cycle i am guessing.

[Tomcat]

Originally posted by vecna35
Thank-you very much Tomcat. I think thats the first example I have ever seen for Long Range Sensors. I can guess how a non cloacking ship can achieve surprise (running silent for 10 days or hiding behind a planet. Something like D&D where u have to hide somewhere to even achieve surprise.

It is my pleasure to help! And yea, ships without the ability to cloak are at a disadvantage. In my EMCON house rule, I tried to accomodate the issues of 'running silent' but you can still run into problems when sensors can detect mass and elements.

It is hard to define sensors in this game especially when a player could say I am sweeping the area for life-forms... or biological matter, stuff like that. The Table 7.2 says that that is a TN 10 in itself - so if a ship were cloaked or running silent would it matter?

Originally posted by vecna35
How often do you allow the Long Range sensor check? 1 day? Every hour?. whats preventing PCs from scanning every min? whith short range its every round but for long range, they will surly see someone 9 days away if they scan every min. There must be some form time cycle i am guessing.

Depending on the range (like in my first example), I might say that the Long Range Sensor tests are Extended tests - with an aggregate TN of 80, each test is TN 10 (plus mods) and they add together until the 80 is met. Each TN 10 test takes 2 hours and if one is failed, the whole series of tests must be started over. This requires 16 sensor hours to identify the far away contact - and even then it is only a blurb on the scans.

I base a lot of my thoughts of how sensors work in Star Trek, on modern day submarine tactics. A submarine moving passively is very hard to detect (emitting very little sound) but an Active sub may be heard from great distances away, although it may not be able to be identified. At agreat distance an Active Sonar will not detect another sub, but at closer ranges, the Active sonar can see depth, bearing, even size.

My above sensor tracking example is like a sub tracking a contact and trying to generate a 'solution'. The solution is its bearing and distance and this data is then fed into the fire control systems.

Anyway, my point is when my players are using their sensor scans, I look at what the book says that they could detect and then how the sensors are being used and come to a happy medium. Like I said in my first post, and it is something I agree with, sensors should also be controlled by the story and what the Narrator wishes to reveal.

NOTE: I have never served in the Navy or worked on any of the sonar systems, so I could be wrong in some of my statements above - this is just stuff that I have learned from reading (and playing sub simulations), but I do not think myself an expert on the topic in any way.

[vecna35]

Originally posted by Tomcat


Depending on the range (like in my first example), I might say that the Long Range Sensor tests are Extended tests - with an aggregate TN of 80, each test is TN 10 (plus mods) and they add together until the 80 is met. Each TN 10 test takes 2 hours and if one is failed, the whole series of tests must be started over. This requires 16 sensor hours to identify the far away contact - and even then it is only a blurb on the scans.

Finally we have (in my opinion) an idea to work off when it comes to long range sensors. Your idea above sounds cool. I am sure someone here might offer another solution but until they do Yours is the first idea about how Long Range Sensors should be run. If it wasn't for your comments I was going to eliminate LRS because my players insist on using it and it would seem to always screw me up when I did not know the TN or time it took.

Cheers!!

[Tomcat]

After a night's rest, this came to mind as well...

Modern day subs run all of the sound transmissions through filtering software in their computers. This keeps the sonar guys from chasing after 'ghosts'.

You could do the same thing with the scans your players are getting with their ship. With all of the tons of mass in space (albeit separated by great distances), there is going to be some stuff the ships scans filter out or may conclude as benign or standard space 'noise', 'stuff', or whatever. So as Narrator, even though they may make some successful tests, tell them that they successfully detected an asteroid or other large mass with metal elements. At long range (days away), the captain would have to make a serious deviation in his course to 'check it out' - only to find it turns out to be a large hunk of metal floating in space.

As Narrator, we can determine what the 'data' is and how it 'reads' to the sensor operator. Is it a ship or an nickel cored asteroid?

Enough said... I am glad I was some help to your game Vecna, thansk for listening to me ramble.