Identifying Starships

By mwagner626, in Rogue Trader Gamemasters

Do starships give off an RFID identifying their ship (like in star wars) or would the rogue trader have to hail them to find out who they are?

Imperial ships might have some sort of identification beacon, but I would consider it foolish to leave it on when operating outside of Imperial space.

The way I ran this, Imperium ships could have a unique 'transponder' signature which would identify them up at 60-100 VUs range depending on stellar conditions. All Naval & Chartist ships certainly should have this. Rogue traders can have such an identifier, but have the option to disable it so long as they are outside the bounds of the Imperium proper, at their own discretion. I determined that the Navy, Mechanicus, Inquisition and most RT dynasties would have built up their own recognition algorithms of known vessel profiles over the centuries and a simple Augur operation could identify a ship at up to 30 VUs range if its' specifications were stored in the cogitator banks (unless it had been hugely modified since last algorithm update).

Ships should have a voxponder (RFID transponder), but as has been mentioned (and is also discussed at length in Traveller, the Serenity RPG and the WEG Star Wars), leaving it on all the time is **** stupid. Sure, when in Imperial space, and you don't want to be mistaken for invaders/raiders you leave it on. If you're doing something dodgy, or merely spooging around in the outer reaches of a star system, you want it off, however: an active voxponder is just screaming your location and identity to anyone in range, and even in Imperial space, a lot of them will not be friendly (pirates, local customs enforcers, the Navy)...

It's worth noting though, that the Imperial Navy doesn't generally pay attention to what ID a (potentially hostile) ship is squawking when it comes to identifying her: they look at the EM signature generated by her engines, combined with the RF spillage from all the electronics and electrics aboard her (which are modified somewhat by the shape of her hull), and her observed speed/acceleration. If they're close enough, they'll have a look at the hull through a telescope as well, looking for any distinctive repairs and modifications, and how she's decorated. All of those data can then be correlated with stored records and shipping registry files to identify a particular ship.

Astropathic Messages can be used to ID ships if they have astropaths or whole choirs aboard and a coded system is used (which would have to be set up ahead of time) to make identificaiton as easy as comparing a ship's ident code to a registry. "Who are you?" "We are BLA BLA Code 434 Baker." Of course trusting the id is up to the captain who's asking.

Ships usually also carry a massive database on other vessels known to be in that sector, so you'd just have to get within sensor range, scan it, and then you'd know what class it was, and then use any identifying markings to figure out what individual ship it is.

Waaay back in the day, ships (earth ones) would carry a big book of schipsilouettes (sp?), these would be used to identify which ship you where watching.

I've ruled for my stories that the cogitatorbanks carry a 'book' like that, which the players can use to identify opponents. Basically: The bigger the ship, the bigger the chance its in the book.

BossTroll said:

Waaay back in the day, ships (earth ones) would carry a big book of schipsilouettes (sp?), these would be used to identify which ship you where watching.

I've ruled for my stories that the cogitatorbanks carry a 'book' like that, which the players can use to identify opponents. Basically: The bigger the ship, the bigger the chance its in the book.

Nice idea. It also occurs to me that not only are bigger ships generally more important, but they are rarer and easier to catalogue. There are only a handful of ships bigger than cruisers in Calixis and Koronus for example.

According to the setting material, every Imperial ship is registered in their Segmentum fleet headquarters.

Naval ships of the segmentum fleets are also registered in other segmentums, to avoid embarassing incidents. Some non-naval ships also have this privilege though its much rarer. The older a ship is, the more likely it is to be registered across more then one segmentum.

All registered ships would thus be able to transmit transponder information identifying them to their segmentum naval elements. Such things would be updated fairly regularly via astro-pathic communications and thus be fairly up to date. Most ships getting registered would also probably be required to spend some time being "processed" to assure that its registry is updated across the segmentum.

ANY ships not transmitting an imperial transponder are automatically considered hostile by Imperial warships and defensive installations, and risks being fired on without warning. If you operate in Imperial space, your transponder is likely to be "on" all the time unless you have a pressing reason to shut it off (crossing an area known to be frequented by pirates) but ready to be re-activated in a moment's notice (in case you run into the naval squadron hunting the afore-mentioned pirates...).

I believe most of this stuff is detailed in Into the Storm.

I liken the ID beacon to flying a national ensign in the age of sail. Its enough to prevent an immediate hostile response, but the captains of each ship would still pull out their looking glasses (or the WH40K equivalent) and check for things like rigging, name on the stern, figure head, etc to confirm the other ship's identity and friendly status.

Bear in mind these transponder signals will have been built with the ship, and are likely very, very old. Given their age, the likelihood that anyone actually knows how to shut them off and turn them on becomes smaller and smaller as time goes on, and among pirates who may lack officially trained personnel and will have quite often come to captaincy under dodgy circumstances, I find it likely most Imperial ships will be broadcasting at all times. I mean, with no understanding of the technology involved, somebody might turn it off, and the family that has been watching a particular bank of indicators for twelve generations will find the prophesized coming of the end has arrived and trigger mass suicides throughout the ship as the crew commend their souls to the Emperor.

I would say these signals are unique to the ship, and contain the most basic of information; Ship class, Captain, millitary designation if it is (or ever was) a naval vessel. Chaos ships would instead be broadcasting heretical scrap code that may melt the mind of whoever was MIU'ed to the augery at the time, or simply cause him to degenerate into maniacal laughter for the remainder of his (likely short and miserable) life. Pirates would vary immensely; perhaps if they possess a talented Enginseer Prime and a group of skilled Tech Priests, they may know enough to change or disable it, but most of the tiem I would see the signal being active.

In terms of mechanics, the signal would be as difficult to detect as the ship itself, and would be suppressed by the same machines and systems that allow Silent Running, but unless attempts at subterfuge were made by skilled hands the beacon would remain.

A thing to consider before implementing anything like this: A transponder receives a signal and transmits a responds. In aviation, classical primary radar - as in, radar that just sends out a brute force signal and checks for reflection - is limited to less technologically equipped air traffic control regions, or to military applications; it also makes absolutely no use of transponders whatsoever. Most modern civilian ATC is performed by so called secondary radar, which sends out a significantly less power intensive signal that triggers a response from a transponder. That response could contain anything from a simple altitude code, to a four digit ID associated with a specific flight plan in ATC databases, or actuall aircraft callsign and flight information, depending on sophistication.

If we are actually talking about transponders, I think its a pretty safe bet that imperial ships are not, in fact, broadcasting all that much unless hit by active augury. Which hidden pirate raiders likely aren't going to use continuously. As to what information the signal would contain... who knows. The greatest safeguard against falsifying such a signal - normally a simple task - would probably be that too few people know about the technology involved. I wouldnt put it past an explorator to do so, though.

Unless of course those things aren't real transponders, but relatively new inventions, going powercrazy and ridiculous as many technological things in the Imperium.

In terms of identifying a ship I run it like how a submarine can identify another submarine. Submarines identify one another by analysing the engine noise of the other submarine against a library of known engine sounds; this can even be done to pick out specific submarines and not just its class. That is how I approach how ships in the expanses of space read each other at long range, all ships have as data library of registered engine harmonics to go with the vox transponders so even with a vox transponder off your unique resonance will give you away. Now I do not mean sound when I talk about engine noise or resonance but the energy signature from the plasma drives, all ships are so unique that even if you took two cobra destroyers from the same ship yard, where they were laid down and finished at the same time you would get a unique signature from each ship.


When I have my crew pick up a ship I use a sliding scale to see how much they can get from their sensors.
1. Distance, further away it is the less info they could get on a normal success with sensors
2. Is the ship large or small, bigger the engines the less of an impact range will have
3. Is the ship imperial and if it is would it have a registered vow transponder or has the crew gone out of their way to change the vox signal
4. Has the crew changed the energy signature as well to say appear like a smaller ship by powering the engines down like running silent etc


It has really worked well for my group and they have enjoyed situations where they play cat and mouse in a star system hunting another ship each one trying to get into a good position to attack the other running silent listening for engine noise.

It's a DM's call IMO.

You can either use a "Sonar" system where the warp signature or the "Sublight engine" signature, etc.

If some ship do open automatically Vox Channels to braodcast the Word of the Emperor, I also do some War horiented machine spirit may challenge any Automated defence etc.

Also, when running "Silent", any transmitino mde by the crew may be picked up. So it may be worh it to have a player doa charm/intimidate to insure no ones uses a radio/ wire-less Vox...

It mentions in the Core book that ships are registered. Thus, registered ships will show up on an Auspex. So once registered, it may always be registered as a certain type of ship unless this is changed.

Unregistered ships can be used and pirates and smugglers do use them, but don't be shocked when you get fired upon because the Imperial Navy shoots at unregistered vessels on sight.

And then there's a simple database of what class a ship is to be able to tell that an infamous pirate or such is coming at you even unregistered, but that would have to be updated from time to time.