Help - Search - Members - Calendar
Full Version: Senses Range
Dumpshock Forums > Discussion > Shadowrun
WhiskeyMac
I have a question that's sort of been gnawing at my brain for a few days now. If I have thermographic vision and I'm using a scope to target someone in extreme range, does my thermo provide a vision mod? Example: Using a sniper rifle at extreme range would make that 1500 meters. Would my thermo vision be able to pick up heat signatures that far away? Even if it's in the city with all the ambient heat around?

Also, would my ultrasound be able to go that distance and provide a vision mod?

How could thermo vision be able to see 1500 meters (over a mile) but not through a 3 inch thick wood door? Maybe I'm just thinking in the wrong way or something.
Mistwalker
You can't use your vision mods thru a scope. If the scope has vision mods, you can use them, but not your own.

Ultrasound needs some kind of projector to work, so over long distance, would probably not work

Your own vision mods will allow you to see in thermo at 1500 meters, but you will see little tiny bits moving about, sorta of like the ant sized people you see when you look that far with normal vision.

Your 3 inch thick door will not transmit the heat from a body in a defined shape. You may end up heating the door a couple of degrees if your there long enough, but no nice little silouhette.
WhiskeyMac
Would my thermo work if I'm using my Vision Mag mod at it's farthest distance possible? It's just really incredible to have a heat sensor pickup out to a half mile or more.
cetiah
Heat and infrared is not the same thing. We have telescopes that can measure infrared radiation from distant stars and planets. Military have infrared sniper scopes. That doesn't mean you can literally feel heat from all that range and an infrared sensor doesn't measure heat. But by reading the measurements of infrared radiation, you can determine how much heat is there.

Originally I was going to post something like "heat creates infrared energy which are then transmitted as photons" but I decided to do a little research first. Here's what wikipedia says on the subject:

"Heat"

Main article: Thermal radiation

Infrared radiation is popularly known as "heat" or sometimes "heat radiation," since many people attribute all radiant heating to infrared light. This is a widespread misconception, since light and electromagnetic waves of any frequency will heat surfaces that absorb them. Infrared light from the Sun only accounts for 50% of the heating of the Earth, the rest being caused by visible light.[citation needed] Visible light or ultraviolet-emitting lasers can char paper and incandescently hot objects emit visible radiation. It is true that objects at room temperature will emit radiation mostly concentrated in the 812 micron band, but this is not distinct from the emission of visible light by incandescent objects and ultraviolet by even hotter objects (see black body and Wien's displacement law).[6]

Heat is energy in transient form that flows due to temperature difference. Unlike heat transmitted by thermal conduction or thermal convection, radiation can propagate through a vacuum.
WhiskeyMac
Yeah, after posting this question I realized that I've stayed up to long and should probably go to sleep. Shit, local police use a infrared/thermo (whatever the hell it is) camera on their copters to track guys running in the bushes and it has a really extreme range.

But it's a no for ultrasound out to half a mile? Or does that actually make sense as well and I'm just completely brainfried?
cetiah
Ultrasound is what they use to take pictures of the ocean floor.
Garrowolf
I wonder if dolphins can hear that and get freaked out when they measure it.
cetiah
QUOTE (WhiskeyMac @ Feb 9 2007, 03:34 AM)
Yeah, after posting this question I realized that I've stayed up to long and should probably go to sleep. Shit, local police use a infrared/thermo (whatever the hell it is) camera on their copters to track guys running in the bushes and it has a really extreme range.

But it's a no for ultrasound out to half a mile? Or does that actually make sense as well and I'm just completely brainfried?

I went online and so far the best infrared rifle scope I've been able to find extends out to 0.28 miles, about half the range you're talking about. It can detect a person at that range under optimal conditions.

Also it appears that while a lot of the limits of IR range and detection are based on physical unchanging laws, there are still dramatic room for technological improvement, including spot ratios and resolutution/precision.


Btw, you can dramatically improve the range of infrared detection if you are willing to bombard the viewed area with infrared radiation. It would work a lot like ultrasound. I don't see why a specially-made grenade couldn't do this. It could give off infrared light, but have no other visible effect.
Garrowolf
Why not an infared laser that heats up the target a bit?
cetiah
QUOTE (Garrowolf @ Feb 9 2007, 05:03 AM)
Why not an infared laser that heats up the target a bit?

Well yeah, that's basically what I meant by bombarding the area. The problem is this isn't very stealthy. Hence the grenade suggestion.
Garrowolf
I was thinking a few degrees, enough to notice a change on the scope easier. I wasn't thinking of frying them.
cetiah
QUOTE (Garrowolf @ Feb 9 2007, 05:40 AM)
I was thinking a few degrees, enough to notice a change on the scope easier. I wasn't thinking of frying them.

I think you're misunderstanding me. And its my fault, since I was trying to be clever or witty and instead just came off as vague.

You don't have to fry them OR change their temperature. You just have to transmit infrared radiation to that area (in this case, an area being a cone that extends out to the victim and the area around him you want to see). This is an active imaging system. It's similiar to how doplar works. Or radar, or ultraosound. Same concepts, but different wavelength of energy - operating in the IR spectrum so that the corresponding echo can be read by an IR sensor.

It's also the way Infrared Lighting works in the Running the Shadows section of the SR4 book.

The problem with using this active infrared radar technique is that you have a very visible cone of IR energy extending out from your gun (or whatever) to the target. Anyone who had line of sight with you and IR vision enhancements would be able to see that cone of light and see what you are doing. Then they might decide to shoot at you - and that's a problem. That's why I suggested using the grenade as an alternate source of light - because it can't be traced back to you. Think of it like an IR flare. Alternatively, you could just plant the scope somewhere and move away from it and shoot from anywhere you like. So long as the IR energy is hitting the target, your infrared vision enhancements will be able to see it. And who cares if people decide to shoot at your scope?


(Btw, your "heat laser" idea wouldn't work. You'd have to heat him up quite a lot in order to adjust the frequency of his IR radiation so that you can read it at a significantly longer range. Also, it would only paint that little IR dot on him from the laser. Enough to "tag" him, I suppose, so you have something to shoot at, but not enough to get a picture or image using your IR vision enhancements.)
blood_kite
I recall in the Gear section under flashlights that you can buy flashlights in normal, low-light, or thermal versions. Just put a thermal flashlight on a drone and have it light the area up for your sniper. It gives your sniper a clearer target and distracts them with something to shoot at.
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.
Dumpshock Forums © 2001-2012