Thermographic Questions Options

[Nightshade-]

Ok, I have two question.

I have a guy in my group that swears and insists that thermographic vision can see through walls and pick up the heat given off by something in a room well beyond the interior wall. Put simply he claims that if he is using thermo while walking through a hallway, and he looks at a wall he can see through it and pick up the heat from a troll that is 10ft or more into the room. Is there anything in the rules that says that is possible? Are there any thermo imagers in the real world that can do that?

I've heard that trolls and dwarves see in normal vision and thermo vision at the same time. I've heard that's the way it's done in some novels as well as it is discussed in the 2nd Ed. book Cybertechnology. The reference that says that states it is in the discussions in the book IIRC. Not sure what IIRC means. Does anyone know what area or page says that? Or is there anywhere else in any rulebooks that it states that and what page please?

[mfb]

no to both questions. the guy is either insane, or he's confusing thermo vision with mm-wave radar. different materials are transparent to light from different parts of the spectrum. thermo vision, in SR, basically allows your eyes to see into the near infrared. very few building materials are transparent in the near infrared--including glass; you can't see through windows if you're only using thermo vision. many building materials, however, are transparent to millimeter wave light--but there are no rules for mm-wave vision.

[SL James]

... yet.

As for the meta vision, that should be in the SR3 rule book. is on p.49 of M&M. They are active all the time.

[The Stainless St...]

[Dog]

The see-through-walls idea is often based on one particular scene in the movie Robocop. I don't think that it's ever actually referred to as thermographic, but the hero looks through a wall and sees that colorful red-people-on-blue-background effect that we laypeople imagine as thermo imaging.

By the way, I've heard about fire-fighters using some kind of portable imaging device to locate people in burning buildings. Anyone know how that works?

[Serbitar]

You can only see hot immovable objects through a wall.
But it is possible to see humans through curtains and such if the stay there for some minutes, but not if they are fast mooving.

[SL James]

Firefighters use an infrared thermographic camera that can differentiate between objects of different temperatures so that they can see people who need to be rescued or hot spots that need to be contained while not being blinded by the smoke.

[Dog]

To penetrate smoke, not walls. Got it.

If I can be picky for a moment, Serbitar, it sounds like what you're describing is that one would see the heat transferred from a hot object onto a chunk of wall. In that case, you'd have to take into consideration the heat conductivity, etc. of the barrier itself.

[SL James]

Indeed, you would.

[Serbitar]

[Crusher Bob]

In the US, most interior walls are sheets of sheet-rock seperated by air. This means that any heat something leaning against one side of the wall transferred to the wall would be diffused by the air spacing in the wall as well.

[KarmaInferno]

[Butterblume]

It is theoretically possibly to see someone using thermografic vision through a wall, if the circumstances are right. Most are mentioned already, the target didn't move around much, the walls are good heat conductors (stone is, wood isn't, for example). The temperature of the building and your surroundings is a factor, etc.

Basically it's just easier to disallow this at all :).

[Findar]

Actually the scene I think of is from the Seals movie where the sniper sees the guys behind a brick wall and shoots them through the wall with his Barret sniper rifle.

[SL James]

"Ooooh, Navy SEALs!"

Yeah... No.

[mfb]

heh, at least it's not U.S. SEALs.

regardless. i'm not going to say that there isn't a scope that does what Paxton's scope does in that movie, but if there is, it's not an infrared (ie, thermographic) scope.

[Frag-o Delux]

I want the railgun and scope in Eraser.

[SL James]

[Oracle]

But he/she/it doesn't tell anyone.

[mfb]

he tells me. that's how i know who to kill.

[Cray74]

[mfb]

god says you can live, Cray.

[Critias]

For now.

[SL James]

I like the tricks sp... Milholland wrote about in SOTA63 (Keeping the Rabble Out) about using IR reflective paint to ambush people coming around corners who don't have thermographic vision.

[Dewar]

[PBTHHHHT]

Some things are best left unknown. Though I guess it'll be a great plot for some gay porn movie. Again, something I wish not to know or dwell upon. :-P

edit: And no, they were meaning that the firefighters were not wearing boots so their body heat could easily be transferred from their feet (and socks) to the floor.

[Grinder]

We don't who did watch the test? Some female scientists maybe?

[PBTHHHHT]

Now now, try and remember that there's audience of not just females out there who wouldn't mind watching this sort of thing.

[Shrike30]

Hey, most girls I know think firefighters are hot.

Besides, there's some female firefighters... :P

[SL James]

But the vast majority don't look like Diane Farr, or even come close.

[HullBreach]

Ive had a little bit of expeirience with Infra-red (Simalar to thermo, think the black and white FLIR footage you see on those police chase shows) weapon sights courtesy of uncle sam, so I'll chime in a little.

IR sights do operate on the principal of infra-red radiation, which is basically light outside the human visual range that is associated with heat. Now 90% of using one of these things effectively is a basic understanding of how radiant heat behaves, as well as knowing what IR light will and won't pass through. Some examples:

You can see through most fabrics very easily, but it does haze up the details a bit. I remember being able to clearly make out people moving inside a tent from over a mile away, though their light discipline was excellent and I couldn't even make them out on NVG's.

Foiliage is also pretty ineffective at blocking light in this spectrum. Tree trunks will, but bushes and other greenery barely even break it up. I remember being able to tell where one dude had just finished taking a leak before heading back to his fighting hole because I could still see the hot piss running down the tree trunk. Pretty wild.

Depending on the sensitivity/sophistication of the unit (I've handled both 'grunt proof' simple models as well as one scientific insturment grade model) you can aslo tweak the settings to 'acclimatize' its settings to function better in your enviroment. We had one tuned so finely, we could tell you which troops were using their MRE's heater tabs while eating their dinner in their fighting holes (they release some hot vapors when activated).

Now thermo is about 10 steps more complicated, requires more training to use, but it is also a hell of a lot more capable. A well tuned IR unit lets you see hot or cold. A well tuned Thermographic unit lets you see HOW hot or cold a thing is. In game terms, this could be pretty useful in a variety of situations. Folks using thyroid boosters and certain other high-performance bioware will either have higher body tempatures or distinct hot-spots associated with the gear. The footprints on the floor scenario metioned earlier is also possible with this level of gear.

Also note that disturbed earth is easy to spot using this, as the newly exposed earth will generally be cooler. Aircraft can actually spot some heavy vehicle tracks hours after the fact from the warm tracks caused by the intense ground-pressure of their passing.

As for the walls scenario, it comes down to construction materials and insulation, but a player whose been leaning against a wall for 10 minutes will be visible on the other side dead-air space or no, simply due to the radiant nature of heat.

Spent shell casings are very visible in both IR or thermo (I think they're a little easier to spot in the black-and-white IR displays though), as are hot gun barrels. The hot gasses associated with firing tend to dissapate very quickly.

Finally, some chemical compounds that are inherantly unstable (high explosives, particularly cheap soviet bloc ones) are usually slightly warmer than ambient tempature due to the fact that they are essentially decaying.

The important thing to remember here is that its all about contrast. A 98deg F human body in the snow, or even a nice 74deg F office building is easy to spot. They are also easy to spot in a 110deg F metalworks. But stick them in a 98-ish degree F jungle, and they will blend in fairly well.

Also take into account shapes. The part of our brain that processes images is pretty well tuned to spotting people. But once we start to break up their shape a little bit, it gets tougher. Israeli infantry wear lumpy misshaper helmet shrouds for this reason, it breaks up the head-and-shoulders profile most troops insticntually look for (mostly cause thats how our targets are shaped). Simply mottleing and breaking up ones IR pattern with some enhanced camoflage (the new cammies used by the Marines and Army utilize material that does this) goes a long way to hiding ones self.

This is why Thermal/IR systems are used to supplement other systems, as without tons and tons of field usage, they just arent that insinctual to use.

[Fix-it]

I'm guessing this was RECENT equipment Hullbreach?

as in, a year or two?
what generation are they on for NVGs anyway?

I got to play with a pair of 1st gen (god they were bulky)

and 3rd gen (better but still fuzzy) night vision goggles, and I couldn't see to well with 'em...
IR sounds like fun. too bad it's restricted tech we civilian pukes won't get for another few years. and then have to pay an arm leg and left eye for.

[HullBreach]

These are actually availible to the public:

http://elcan.phpinternet.com/www/SPECTER_0_0_Index.htm

But they cost like 12k last time I checked. Hell, I can't even afford regular range time lately, so somthing like thats a wish for if I hit the lotto!

While I was in we were using Gen 3 NV gear, which has gotten much better. Supposedly the next gen stuff will be almost as sharp as normal vision due to some new manufacturing process for the intensifier tubes (which I've always felt were the weak link, give me an IR enhanced CCD instead!).

The thermo and IR stuff was mostly demonstration samples I just happened to be in the right place at the right time to handle. The IR weaponsights are probobly going to be GI issue for crewserve weapons in the near future, so thats good news as it will drive the public prices down some.

[KarmaInferno]

[Moon-Hawk]

Well that's what makes the hunt challenging, what with humans being so squisky and weak. :-)

[SL James]

Please don't tell me you're trying to apply science to an action movie.

[Fix-it]

yeah, you really shouldn't bother with a movie that features an average guy shooting a minigun from the hip.

[KarmaInferno]

Jesse Ventura is not an average guy!

He's Jesse Ventura!

You take that back!


-karma

[LilithTaveril]

/me sets Jesse Ventura on fire.

[Smokeskin]

AFAIK full recoil force from a 5.56 minigun is around 500 newton, or around the effect gravity exerts on 100 pounds. Braced against the hip, a strong guy should be able to handle that.

[RunnerPaul]

[Austere Emancipa...]

It was an M134, so a 7.62mm minigun. Even then, though, at 2000rpm, perhaps even 3000rpm, a big guy would be able to handle the recoil, to an extent -- I don't know about the other peripheral problems of firing such a weapon unmounted. But he certainly wouldn't be able to lug around the 200+lbs of gun, batteries and ammo, assuming he's to fire it for more than 30 seconds.

[SL James]

True, but to be fair Blain fired it in short, controlled bursts. It was Mac who went apeshit and let the thing fire until it ran out of ammo.

[HullBreach]

Ahem.....the mini-gun thing has been well documented as impossible here:

http://world.guns.ru/machine/minigun-e.htm

Scroll down, its towards the bottom. These guys know there shit, I trust what they say.

[Austere Emancipa...]

They make the mistake of assuming that the gun would be set to fire at 6000rpm. The most recent M134 models fire at 3000rpm, the ones from when Predator was filmed mostly fired at either 2000rpm or 4000rpm. At 2000rpm, we're only talking about a bit over twice the recoil of an M240 -- and according to The Gun Zone, the RoF on the Predator M134 "was reduced to 1700 rpm in order to reduce torque and to lower the voltage required to power the motor that rotates the barrels." They're absolutely right about the weight issues, though, and I have no idea how an M134 ejects empties.

[Smokeskin]

Imo the guys who wrote that at guns.ru have very little idea of what sort of force a human can brace themselves against. Even the 120 kg recoil from an M134 shouldn't knock a strong man over if he was properly braced for it.

If they reduced the cyclic rate, then it becomes much more managable. I've fired 7.62 NATO ammo from a 11 kg LMG at 1200 rpm from a standing position, hanging at the hip but with no hip-brace, without a problem. At 1700 rpm, with a heavier weapon and the centripetal stabilation effect from the rotation barrels, recoil would be even less. If you added a hipbrace, I should think you could easily go double that.

[HullBreach]

[HullBreach]

[Austere Emancipa...]

[HullBreach]

A valid point, I got my number confused for a few moments there (I just woke up, still absorbing cafffine).

On a semi-related note, the US Military (I've only seen the Army do it so far) has began using M-134's on top of Hum-Vees. This is kind of an interesting development, as it really provides a crazy level of firepower to respond to an ambush with.

Personally I've always liked the MK-19.

[Austere Emancipa...]

Apparently with 9000 ready rounds. I'd say a Mk 19 provides quite a bit more firepower, but I guess for the work they're currently mostly engaging in it also tends to cause a bit too much collateral damage.

[HullBreach]

Initially I would agree with you, but a 40mm grenade doesn't have that much penetration, and will self destruct before it goes too far.

On the other hand a stream of 7.62mm FMJ ammo will cut through a whole neighborhood of residential houses.

Now the mud brick construction of the homes in the middle east probobly attenuates that quite a bit though.

[Austere Emancipa...]

The M549 is a self-destructing fuze? If so, that's more than 2km away, at which point most 7.62mm ricochets are pretty harmless as well. :)

A single 40mm HEDP grenade penetrates about 60-75% as much of the most common exterior wall materials as a 7.62x51mm FMJ at close range (according to FM 90-10-1), and every one has a casualty producing radius of 15 meters. If I had to choose one weapon to fire at my residential building for 30 seconds, I'd absolutely take the M134.

[HullBreach]

[Austere Emancipa...]

The M134s they have on the HMMWVs are fixed at 3000rpm, AFAICT. At 50 rounds per second you will see impacts close to each other, but they don't quite bore a straight tunnel through buildings. :)

You'd need to concentrate your fire on one spot for a second or so to get penetrations through 2 or 3 serious outer walls (you need dozens of hits before you get a large enough hole in the first hole to get the next bullets clear to the next one). In the same time the Mk 19 has fired 6 times, which will penetrate about as far assuming similar accuracy. Only difference is that people in the rooms the Mk 19 shot through are rather more likely to be dead.

[HullBreach]

Im really curious to see the performance of the new 25mm grenades used by that OICW monstosity the army is funding. Im guessing, based on their capacity, that the grenade launchers in SR lean more towards that form than our old 40mm bloop guns.

Theres also this nugget of fun Barrett has in the works:
http://www.barrettrifles.com/military/images/109b.jpg
More data at:
http://www.barrettrifles.com/

Im pretty sure that thing is the basis for SR's assault cannon!

[Kagetenshi]

He who has not read Dumpshock is doomed to repeat it ;)

~J

[Austere Emancipa...]

It isn't the basis: the whole SR Assault Cannon thing comes from the Cobra Assault Cannon in RoboCop, which was a Barrett M82 with crap tacked on. However, it absolutely is the closest and most logical RL match to the weapons as they are described in SR3 and SR4. This has been established in quite a few "Panther Assault Cannon, What Is It?" threads. :D

[HullBreach]

[Smokeskin]

I actually think we were supposed to change barrels after 150 shots with the MG3, but it's been a long time since I was in the army, I could well be wrong.

It should be said that for military purposes, being able to fire it from a standing position is hardly a requirement anyway. You fight from a prone position with few exceptions.

[Austere Emancipa...]

In the long term, barrel damage will probably start to occur in the (very) low hundreds of rapid fire with most LMGs and GPMGs, which explains the rather low suggested amount of rounds changing barrels. If you don't mind shortening the barrel life significantly you can keep going much further. I would not be surprised if an MG3 could keep it up for a full minute before critical failure (e.g. barrel blow out), since an M60E4 can (sometimes) manage 850 rounds cyclical.

[HullBreach]

Those Echo4 mods on the M60 are pretty sweet, but I hear the barrels are insanely expensive due to the materials. They use some crazy alloy that wont begin warping until well after cook-off tempatures are passed.

[Ed_209a]

My personal feeling on the matter is that a minigun has no place as an infantry-mounted weapon. I believe the additional rounds on target compared to a more conventional LMG is neglegible compared to the weight of the weapon and the wasted ammo to gain those extra hits.

When you talk about vehicle mounted miniguns, I am still a little hesitant, but I am at least willing to listen.

My feeling on the matter is that miniguns are really only called for for either air-to-air combat, air-to-ground, or surface to air.

[HullBreach]

I agree with you for the most part.

A good example of machinegun design is the differences between the German MG-34 and MG-42 light MG's. The MG-34, while more complicated to produce and having a slower rate of fire, was a devastatingly accurate weapon. The MG-42, if you overlook it's morale destroying muzzle blast noise, was an inferior weapon in every way other than ease of manufacturing and rate of fire.

[Lagomorph]

[Smokeskin]

Another example of action movies getting stuff wrong:

Just saw Superman Returns last night (I strongly recommend everyone to stay clear of it btw, not even rental quality) and there was a minigun that you saw firing in slow motion - the bullets where about 1 meters apart. So if we assume 700 m/s muzzle velocity (about 2300 fps) the puts us at 700 rounds per second or 42,000 rpm.

Converserly it could be doing just 6000 rpm, but that puts the muzzle velocity at 100 m/s.

They had the minigun mounted on a crane though ;)

[RunnerPaul]

And just rememer: even Superman ducks a thrown minigun.

[Smokeskin]

I dunno, this guy shot him in the eye from point blank range and superman didn't even blink. The eye didn't even move in the socket, no head jerk, nothing. Must be really hard for him to consciously have to respond when people bump into or touch him in daily life, otherwise it'd be like running into a lamp post. Man of steel?

[Smokeskin]