Tracking ships

[Endie]

IMTU, Jump Filters need you to be in Close range, because it needs EM sensors at Full capacity, and range extending hardware doesn't work because the fundamental particles involved have half-lives of less than 35 microseconds, so too many decay (assuming they travel at very close to the speed of light in a vacuum) to perform the calculation after about 10km.

The software gives a bearing and range to the nearest parsec. So if they jump out within 10km of you to an apparently-empty sector then you can guess that they have a fuel cache, or a tender, or they have extra fuel in their hold etc.

If you follow them then you'll end up in the same hex, and you'll drop out within a few hours of them, most likely. Great.

I'm sure that it's canon (but God knows where I read it in the last couple of weeks! JTAS?) that the Imperial Navy are performing experiments to improve this capability, but I don't want people able to track each other accurately, or there would be no pirate bases or the like in-game. So with a lot of effort you can get some basic info that doesn't break the core Traveller universe model.

 

[GabrielGABFonseca]

Wait a minute. Since we are detecting gravity waves, how does the inverse square law apply if the automatic detection threshold is 1 parsec? That means a 100-ton ship can be detected automatically at a range of 1 parsec when entering or leaving jumpspace and a comet can be automatically detected at 0.1 parsecs. Since we are discussing minimum distance for automatic detection, how much less powerful of a gravity disturbance is a small comet versus a 100-ton J-1 ship if both are at their minimum automatic detection thresholds? Is the jumpdrive signal 10x more powerful than the comet or is it something else?

That would depend on the exact methodology behind the Gravitational Analysis Suite's functioning principles. If they're really detecting gravity waves, then you need to have something disturbing space-time in a way to produce said waves. Normal, every day objects (yes, I am counting comets as 'everyday objects', as one does), do not do that to any great degree.

If an analogy would be helpful, think of the classic 'space-as-a-sheet-of-rubbery-material' analogy; having a tiny pebble roll across it barely disturbs it, picking up the vibrations caused by it would be hard. Whereas if instead you were to roll two bowling balls towards each other (say, a Neutron Star or Black Hole merger), or perhaps – and now this is veering away from strict real-world analogy into speculation of my part – throw that same tiny pebble against the sheet such that it impacted with force, like a starship undergoing jump precipitation, that'd cause some waves which might be detectable from much farther away.

Being less verbose, the strength (and therefore detectability) of gravity waves correlates directly to how hard and how fast space-time is being bent, and bodies like comets just don't really do much of that at all.

 

[Talon Greyfeather]

Just out of curiosity... Why does jump tracking even work? Seems to me like watching a plane take off from the airport and magically knowing where it is going. I don't care how well you know the capabilities of the aircraft or how closely you monitor its take-off, that will tell you nothing about where the plane is going.

Im not saying it does. What I'm saying is that based on the jump rating of the ship, you can get an idea of where possible destinations are. It's not like a plane that you can change your destination mid-flight. It's a plotted course to a plotted destination, and you can only go as far as your jump engines can take you (unless you mis-jump). You are locked in to that course for a week. The lower the jump rating the higher the probability of making a good guess of where they are going - depending on the sector and density of worlds.

Again, this would be a referee roll at my table. I have a lot of those where things like this come into play. Aint no magic ... you may get lucky ... you may not ... you don't know until you get there and the target ship is there or it isn't.

 

[MasterGwydion]

That would depend on the exact methodology behind the Gravitational Analysis Suite's functioning principles. If they're really detecting gravity waves, then you need to have something disturbing space-time in a way to produce said waves. Normal, every day objects (yes, I am counting comets as 'everyday objects', as one does), do not do that to any great degree.

If an analogy would be helpful, think of the classic 'space-as-a-sheet-of-rubbery-material' analogy; having a tiny pebble roll across it barely disturbs it, picking up the vibrations caused by it would be hard. Whereas if instead you were to roll two bowling balls towards each other (say, a Neutron Star or Black Hole merger), or perhaps – and now this is veering away from strict real-world analogy into speculation of my part – throw that same tiny pebble against the sheet such that it impacted with force, like a starship undergoing jump precipitation, that'd cause some waves which might be detectable from much farther away.

Being less verbose, the strength (and therefore detectability) of gravity waves correlates directly to how hard and how fast space-time is being bent, and bodies like comets just don't really do much of that at all.

Right, but things we know for fact are that comets are automatically detectable a 0.1 parsecs and jump flash is automatically detectable at 1 parsec with a GAS.

 

[Talon Greyfeather]

MMDV

An enemy can follow you

The game is now different, and not in favour of the PCs.

Just try it, next time your PCs do something questionable have them followed to the next system by people who want to ask them questions

What's good for the goose is goof for the gander. The game is the same for all ... and I do not favor my PCs. Actions have consequences ... for everyone ... makes it fair, no?

 

[MasterGwydion]

Im not saying it does. What I'm saying is that based on the jump rating of the ship, you can get an idea of where possible destinations are. It's not like a plane that you can change your destination mid-flight. It's a plotted course to a plotted destination, and you can only go as far as your jump engines can take you (unless you mis-jump). You are locked in to that course for a week. The lower the jump rating the higher the probability of making a good guess of where they are going - depending on the sector and density of worlds.

Again, this would be a referee roll at my table. I have a lot of those where things like this come into play. Aint no magic ... you may get lucky ... you may not ... you don't know until you get there and the target ship is there or it isn't.

I had not considered misjumps in this, but according to the rules, using a jump filter you know where the ship jumped to even if it misjumped, correct? It also says that the accuracy is to the star system, not to the correct hex, which is much more accurate than you guys are saying when you say accurate to a hex and not to a star system.

 

[Talon Greyfeather]

I had not considered misjumps in this, but according to the rules, using a jump filter you know where the ship jumped to even if it misjumped, correct? It also says that the accuracy is to the star system, not to the correct hex, which is much more accurate than you guys are saying when you say accurate to a hex and not to a star system.

According to the description of the Jump Analyzer Software it gives the potential jump destinations. I interpret that to mean more than one. It's accomplishing the same thing that someone with a sector map and astrogation skill can do - maybe faster since it has a collection of ship classes and their standard jump drive signatures. Heck, depending on the sector, you may not even need astrogation. Nowhere does it detail the level of accuracy or that it only gives the exact location of the target ship - just potential destinations. That could be a lot depending on what the system has in it ... or not.

 

[MasterGwydion]

According to the description of the Jump Analyzer Software it gives the potential jump destinations. I interpret that to mean more than one. It's accomplishing the same thing that someone with a sector map and astrogation skill can do - maybe faster since it has a collection of ship classes and their standard jump drive signatures. Heck, depending on the sector, you may not even need astrogation. Nowhere does it detail the level of accuracy or that it only gives the exact location of the target ship - just potential destinations. That could be a lot depending on what the system has in it ... or not.

and this is merely one of the problems I have with Traveller putting rules and equipment scattered all over the place.

Read below.

 

[Talon Greyfeather]

This changes nothing from my perspective - it's still a prediction of possible star system destinations - not a world, not a station, not a port. A star system can be a big place with lots of places to hide - or not. If you did something to get you tracked, the larger the crowd to hide in the better.

 

[Talon Greyfeather]

and this is merely one of the problems I have with Traveller putting rules and equipment scattered all over the place.

It's the nature of RPGs. Rarely are all the rules ever in a single place and remain that way. It's only good the day its published. The key is having a master index that cross references the source material and has tagging/searching that makes sense for the user. I have such an application in development now ... it even opens up the PDF to the requested page ... along with some other fun campaign management features.

 

[MasterGwydion]

It's the nature of RPGs. Rarely are all the rules ever in a single place and remain that way. It's only good the day its published. The key is having a master index that cross references the source material and has tagging/searching that makes sense for the user. I have such an application in development now ... it even opens up the PDF to the requested page ... along with some other fun campaign management features.

That is only the nature of RPGs because that is how publishers choose to make them.

 

[MasterGwydion]

This changes nothing from my perspective - it's still a prediction of possible star system destinations - not a world, not a station, not a port. A star system can be a big place with lots of places to hide - or not. If you did something to get you tracked, the larger the crowd to hide in the better.

Earth's solar system is over 1 billion times smaller than the parsec it is contained in. Seems like that is a lot more accurate than you were thinking. So, you would know if they went elsewhere in the hex and not to the star system. That could imply the existence or a base or a fuel dump, or other adventure-creating thing.

That means it is 1 billion times faster to search once you send ships there. That would seem to be relevant to the game universe. A star system is reasonable to try and search, an entire hex is not.

 

[Talon Greyfeather]

That is only the nature of RPGs because that is how publishers choose to make them.

So the game should never change once published? Surely you jest!

 

[Talon Greyfeather]

Earth's solar system is over 1 billion times smaller than the parsec it is contained in. Seems like that is a lot more accurate than you were thinking. So, you would know if they went elsewhere in the hex and not to the star system. That could imply the existence or a base or a fuel dump, or other adventure-creating thing.

That means it is 1 billion times faster to search once you send ships there. That would seem to be relevant to the game universe. A star system is reasonable to try and search, an entire hex is not.

You are assuming that it would not return all of the potential star systems in that hex as possible destinations. IMHO, you are giving the technology much more accuracy than intended - but your table, your rules.

 

[MasterGwydion]

So the game should never change once published? Surely you jest!

No, but should be updated and consolidated regularly. RPGs are no longer only print media, so updates can be a thing now.

You are assuming that it would not return all of the potential star systems in that hex as possible destinations. IMHO, you are giving the technology much more accuracy than intended - but your table, your rules.

That is not what it states that it does. It states that, "With detailed analysis, this allows a prediction of which star system a ship has jumped to" (not which potential star system), so no. The rules say it tells you what star system, so you are giving the technology less credit than is clearly stated in the rules. At your table you can do what you like, but don't try and pretend that the book doesn't say differently. Now, you could argue that the prediction isn't 100% accurate, but that is a different discussion and may be a valid one. Then We need to figure out how accurate it is, and how your skill check affects that accuracy. Right now, I am not sure the skill check affects anything other than granting a pass/fail type thing.

 

[MonsterX]

No, but should be updated and consolidated regularly. RPGs are no longer only print media, so updates can be a thing now.


That is not what it states that it does. It states that, "With detailed analysis, this allows a prediction of which star system a ship has jumped to" (not which potential star system), so no. The rules say it tells you what star system, so you are giving the technology less credit than is clearly stated in the rules. At your table you can do what you like, but don't try and pretend that the book doesn't say differently. Now, you could argue that the prediction isn't 100% accurate, but that is a different discussion and may be a valid one. Then We need to figure out how accurate it is, and how your skill check affects that accuracy. Right now, I am not sure the skill check affects anything other than granting a pass/fail type thing.

Talon seems to be saying pretty much the same thing as you. As you point out "this allows a PREDICTION of which star system a ship has jumped to". Madame Mysterieuse can also make such a prediction with her tarot readings, but her predictions are a little short of 100% accurate.

Skill checks in Traveller generally use effect to determine how well a task was performed, so of course here it would also do so.

In this case, as Talon points out, even if you get the destination right, knowing that they went to a specific star system does not mean you know where they are. If I am looking for someone and I know they are "on Earth" I would not say that I know where that person is. Star systems are considerably bigger that Earth. A pursuer would have to guess whether they went to the main world, some other in-system port, a gas giant, or some other alternative wilderness refueling source. This will need guess work, detective work and travelling around the other star system; the pursued ship will almost certainly know they need to watch out and will act appropriately. There are generally dozens - or hundreds of thousands - of plausible refueling destinations in every target system; unless they need to be somewhere specific for specific reasons, the can just refuel and go, your chances of following them are pretty close to zero. If they don't have an on-boyard fuel refinery, you'll have a chance to find them, maybe, unless they risk using unrefined fuel.

 

[MasterGwydion]

Talon seems to be saying pretty much the same thing as you. As you point out "this allows a PREDICTION of which star system a ship has jumped to". Madame Mysterieuse can also make such a prediction with her tarot readings, but her predictions are a little short of 100% accurate.

Skill checks in Traveller generally use effect to determine how well a task was performed, so of course here it would also do so.

In this case, as Talon points out, even if you get the destination right, knowing that they went to a specific star system does not mean you know where they are. If I am looking for someone and I know they are "on Earth" I would not say that I know where that person is. Star systems are considerably bigger that Earth. A pursuer would have to guess whether they went to the main world, some other in-system port, a gas giant, or some other alternative wilderness refueling source. This will need guess work, detective work and travelling around the other star system; the pursued ship will almost certainly know they need to watch out and will act appropriately. There are generally dozens - or hundreds of thousands - of plausible refueling destinations in every target system; unless they need to be somewhere specific for specific reasons, the can just refuel and go, your chances of following them are pretty close to zero. If they don't have an on-boyard fuel refinery, you'll have a chance to find them, maybe, unless they risk using unrefined fuel.

Yeah, but if I know what system they jumped to, I could contact the starport and get further information once I jump in system. The starport will have accurately detected their jump and since you know how big the jump flash was on one end, you should be able to give the starport the ship's signature. If it is as Talon points out and only gives you a list of potential parsecs, then this is not possible.

 

[Condottiere]

If gravitation acts like a wave, in an space ocean full of them, only the most powerful of them would, or should, be detected over interstellar distances.

Being swamped out by others.

 

[Sigtrygg]

Fourier transform...

 

[MonsterX]

Yeah, but if I know what system they jumped to, I could contact the starport and get further information once I jump in system. The starport will have accurately detected their jump and since you know how big the jump flash was on one end, you should be able to give the starport the ship's signature. If it is as Talon points out and only gives you a list of potential parsecs, then this is not possible.

Probably not. 1) the pursuing ships can't always just tell the Starport authorities what to do - unless they can. Most PCs can't, most of the time, but even governments will have jurisdiction issues. 2) the Starport may not have detected their jump Detection is rarely automatic, and it does not tell you anything about the ship. In a busy port you will get 100s of hits, so useless. You can check the transponder signals, of course, but if you are doing that, you don't need the jump flash. 3) By the time you get to check out any jump location, the ship is long gone. 4) the starport needs to have the equipment for this, which poorly resource facilities will not have. It doesn't really seem like something even a well resourced starport is likely to have. Local system defense or IN or Scouts will have this when the tech is available because clusters of ships jumping in during wartime likely signals an attack, but unless you are part of their organization, they're not going to share. 5) if the ship is evading the PCs or if it just need to go somewhere far out in the Oort Cloud, the signal might take days to reach the starport, so it will be a long time before you even get started on the search.