Heat & Stealth.

[Magnus von Thornwood]

So ladies, gents and others,

I am watching my beloved PBS, in this case How We Got To Now which deals with audio technologies. Among notable cool things, yet one more example of chicks rocking science Heady Lamar's frequency hopping and that classic sub tech SoNAR. Which led to sub hunting which led to "No Stealth In Space!", which being a Naval Architect led me back to starship sensors.

The big argument against stealth in space (thank you Aramis, who is almost guaranteed to bring the science for the con side when it comes up) is that space is not only big, really big, you think it's a long walk to the chemist, but that is peanuts compared to space, is that is also insanely bleeding cold.

Which is fine since it is true, but then and this is where the question comes in, why are there no damned IR detectors in Traveller?

We got Life Detectors, Field Sensors of all types, EMS, Comm+ (meson commo), holodynamics, and even Visors, Scopes and plain old Viewports, but not even the most simple thermal sensors.

So, anyone got ideas why that might be?

Should we be lobbying Marc to add them?

 

[Carlobrand]

So ladies, gents and others,

I am watching my beloved PBS, in this case How We Got To Now which deals with audio technologies. Among notable cool things, yet one more example of chicks rocking science Heady Lamar's frequency hopping and that classic sub tech SoNAR. Which led to sub hunting which led to "No Stealth In Space!", which being a Naval Architect led me back to starship sensors.

The big argument against stealth in space (thank you Aramis, who is almost guaranteed to bring the science for the con side when it comes up) is that space is not only big, really big, you think it's a long walk to the chemist, but that is peanuts compared to space, is that is also insanely bleeding cold.

Which is fine since it is true, but then and this is where the question comes in, why are there no damned IR detectors in Traveller?

We got Life Detectors, Field Sensors of all types, EMS, Comm+ (meson commo), holodynamics, and even Visors, Scopes and plain old Viewports, but not even the most simple thermal sensors.

So, anyone got ideas why that might be?

Should we be lobbying Marc to add them?

I wouldn't call space cold, per se. It's actually a pretty good insulator, lacking any mass to carry your heat away. And the sunward side can get pretty hot.

Striker has thermal sensors, but that's ground-based combat. I always figured thermal sensors were just part of the routine ship's sensors for Book-2/High Guard, part of the reason you could sense a ship a quarter light-second out (or one and a half light-seconds out for the Navy) even when it was silent and not maneuvering.

 

[Supplement Four]

There is little on sensors in CT, aside from range in the Traveller Book. I understand that the first edition Book 1 provided a little more on sensors, but that stuff was edited out for later editions.

The idea in CT is that, for the most part, all vessels and objects that are material to the players' ship are known. The CT skill of Navigation is used for ship's sensors, according to the skill description.

Then, DGP provided more detail about sensors in Grand Survey. And, this was reproduced in MT.

HRT (High Resolution Thermal) is one of the sensors DGP describes.

 

[Timerover51]

Putting together a passive Infra-Red sensor array would not be that difficult, but it would have some limitations. To get a range, you would need to either bounce a radar signal or a laser beam off of the suspect heat sources, or following a path to try and determine range by bearing cross-referencing, which might not be easy. Also, if a ship with ill intentions is around, it might try to position itself with the system's star behind it, thereby masking its heat.

I assume a passive IR array as a matter of course for any space ship.

 

[epicenter00]

MT has the Electro-Magnetic Sensor (EMS). Passive EMS would be the one that picks up thermal signatures in space. Instead of it being a dedicated heat sensor, it picks up the whole gamut.

 

[Supplement Four]

MT has the Electro-Magnetic Sensor (EMS). Passive EMS would be the one that picks up thermal signatures in space. Instead of it being a dedicated heat sensor, it picks up the whole gamut.

Oh yes...that one is in the DGP CT materials as well. One of the two "biggies".

HRT, that I mentioned above, includes IR.

 

[Reban]

I thought all the EMS, WSV and the more advanced "camera" sensors all included the IR part of the spectrum

Is there a need for a purely thermal sensor at higher tech levels?

Of course if you can do thermal guidance for weapons at lower tech levels you should be able to say "hey big heat source over there!". Of course how far over there is a more technical question.

You know what else this brings to mind? The lack of "scientific" sensors in Traveller. Astronomical telescopes, spectrometers, and radio telescopes for navigation and mapping purposes.

 

[Supplement Four]

I thought all the EMS, WSV and the more advanced "camera" sensors all included the IR part of the spectrum

Is there a need for a purely thermal sensor at higher tech levels?

You're correct. It is included.

It's been a while since I've read it. I can't remember why HRT was separated from EMS. I haven't read up on sensors (or used my own Sensor rules!) in quite a long time (haven't played Traveller in a long time).

I would need to revisit it.

It might be that HRT is available separately if EMS is not installed. But, IIRC, EMS was a cluster of sensors in the basic package.

 

[mike wightman]

How long does it take to scan the entire night sky in a full sphere around the Earth?

If you know where to look finding an IR source like a ship in Traveller is fairly trivial, the issue, as you have stated, is that space is big.

Remember the asteroid that hit Russia a while back? No one detected that inbound.

 

[Carlobrand]

How long does it take to scan the entire night sky in a full sphere around the Earth?

If you know where to look finding an IR source like a ship in Traveller is fairly trivial, the issue, as you have stated, is that space is big.

Remember the asteroid that hit Russia a while back? No one detected that inbound.

As I recall, that particular asteroid wasn't generating as much power as a small city before it hit atmosphere.

 

[Timerover51]

MT has the Electro-Magnetic Sensor (EMS). Passive EMS would be the one that picks up thermal signatures in space. Instead of it being a dedicated heat sensor, it picks up the whole gamut.

Hmm, one sensor that can pick up the ENTIRE electro-magnetic spectrum. I missed that one in MegaTraveller. You do understand that there is a correlation between antenna size and radio frequency detection? To simply cover the frequency bands commonly used on Earth requires a very large number of different sized antenna. Directional antennas are a different story entirely.

Infra-Red detectors, to be really sensitive, have to be cooled to well below Zero, in some cases for the most sensitive by liquid nitrogen. As plenty of liquid hydrogen is typically available on a star ship or space ship, super-cooling of detectors should not pose a problem, however, you would have to allow for some well insulated piping runs, or some really good thermo-electric cooling systems.

 

[Supplement Four]

Hmm, one sensor that can pick up the ENTIRE electro-magnetic spectrum.

It's an integrated sensor cluster. Active and Passive EMS.

 

[SanDragon]

From the Ref's manual:

"An EMS Active Sensor Array combines radar, all-weather radar, ladar, radar jammer, radio jammer, active IR, and image enhancements into one integrated and optimized sensor array."

"An EMS Passive Sensor Array combines laser sensor, radar direction finder, radio direction finder, radiation sensor, passive IR, light amplification, and image enhancement into one integrated and optimized sensor array."

 

[rancke]

How long does it take to scan the entire night sky in a full sphere around the Earth?

Quite a while. But then you can detect IR sources MUCH weaker than a room-temperature starship at the canonical distances. Basically you're trying to spot a blazing light at very short range.


Hans

 

[Carlobrand]

I wonder how far off you could detect a jump flash with a wide angle sensor.

 

[epicenter00]

You do understand that there is a correlation between antenna size and radio frequency detection?

You seem to mistake my pointing out about something in the MT rules to be my personal opinion. That's just what the MT materials say. More of the gosh-wow technology of the 3I.

 

[Supplement Four]

How long does it take to scan the entire night sky in a full sphere around the Earth?

IIRC, there are tasks for surveying worlds in Grand Survey/The World Builder's Handbook. Those tasks have time factors.

 

[mike wightman]

I meant here in the real world, not in game.

 

[mike wightman]

Quite a while. But then you can detect IR sources MUCH weaker than a room-temperature starship at the canonical distances. Basically you're trying to spot a blazing light at very short range.


Hans

But only if you are looking right at them, if they are outside of your field of view then you have the complication of swinging your detector in a full sphere around you.

Here in the real world we do not have real time spherical scanning of the entire sky as far as I know; for a Traveller ship to have that sort of capability requires almost the entire hull to be studded with sensors.

Is that capability hidden in the bridge percentage perhaps?

 

[Travellerspud]

I always thought a possibly improvement might have "sensor hits" as well as "weapon hits" and "fuel hits" on the top of the damage chart....where each combatant slowly blinds the other...commercial ships gets 4 sensors (or maybe just 1 for really cheap ships or boats), and military ships get many more. Sensor repair is also possible with damage repair crews, etc. Once you go blind, no more weapons until you get a sensor fixed....or no sensors in that facing (or 25% of the foes, etc).