Ultrasound is described as being "...perfect to “see” textures, calculate exact distances, and pick up things otherwise invisible to the naked eye (like people cloaked by an Invisibility spell)..." (SR4A, 333). Descriptively, this makes it sound like you can walk around with your eyes closed or in a completely dark room without any problem. It also sounds like you can detect any invisible person without a problem.

However, the Visibility Table on page 152 of SR4A includes dice pool penalties for ultrasound when you are in less-than-ideal lighting conditions, which implies that ultrasound does not let you see perfectly in total darkness, or even partial darkness for that matter, and by extension implies that you also wouldn't be able to see invisible people with perfect clarity.

So, just how well does ultrasound allow you to "see"? Can you see invisible people without making a Perception Test if they aren't otherwise trying to hide? If you can see invisible people, do you suffer any penalty to hit them in combat, including needing to use Intuition instead of Agility ("Blind Fire", SR4A, 150-151)?

Ultrasound vision is basically "radar" imaging that uses sound instead of radio waves. I tend to envision Unltrasound output as being a fairly low-res image that is mostly black and white, with some false color (or other simsense overlay) to indicate doppler shifts caused by moving objects.

This image would over-lay or be "mixed in" (as edge enhancement, etc) with your normal vision, which is why Ultrasound vision systems would work better in lit Environments than in the dark. You certainly COULD walk around with your eyes shut, or in the dark, but you'd miss out on a level of detail, and might miss certain items (ones transparent to high frequency sound, which isn't to many things) or have trouble making sense of what you see as easily as you would with your normal vision senses mixed in.

As far as detecting invisible people goes, consider this; Ultrasound can't see through glass, because noise bounces off glass pretty well. To ultravision, a window looks like a flat panel of opaque material. Same with a computer display, or poster. Holos and trid probably don't show up either, and camoflauge (unless heavily textured) and Ruthenium stealth suits would look just like normal clothing.
One "explanation" for invisibility is it basically makes you transparent, with the same index of refraction as air. Or, for a more rules based explantion, the Invisibility spell is an illusion that doesn't have any auditory component. So yeah, they are gonna stand out pretty good. I'd expect most vision systems would be specifically configured to highlight anomolies like this, so if something shows up in ultrasound but isn't there in normal vision (or vice versa) it might REALLY stick out.

How do Silence spells affect ultrasound? Does it knock it out or is it a penalty based on the force or hits or what?

IIRC, a silence spell basically creates a big Ultrasound "blackout zone" for its area of effect. Ultrasound can't see anything inside that zone, but it can see that there's a big noise absorbing "wall" there. Not sure if the force of the spell / hits have any meaning for this purpose- I suppose if the Ulatrasound has a rating, you might use an opposed contest to see if / how well it can "punch through".

If you had a non-area silence spell (one that affected only an individual) it would be pretty wierd looking to ultrasound. The effect would be much like looking at somebody who reflects absolutely no light; you'd see a siloette of their shape. Would make judging distance and motion harder, and you'd be at a loss to tell what they were holding, etc. Ultrasound might be a bit better because you could judge how far away they were by pinging the distance to the ground under their feet.

Thanks, Mongoose. To re-ask my final questions: would someone with ultrasound vision suffer a dice pool penalty to attack an invisible enemy? Would the character need to use the Blind Fire rule?

To answer Mercer, I would rule that a silence-type effect is the same to Ultrasound as Invisibility is to regular vision. Thus, the character with ultrasound would need to resist the Silence spell before being able to detect the other person.

I'd noticed that too about how ultrasound takes lighting penalties. My guess is that the penalty represents the fact that ultrasound isn't how a person is 'used' to seeing. It can't be accounted for by low resolution, because it has good enough resolution to pick up textures, which would indicate an absurdly high resolution (less then a mm most likely).

This suggest that the difficulty is with the fact that when looking only through ultrasound (like you would in total darkness or with your eyes closed) it is different enough from what you are used to to cause a penalty. Seems like a bit of a weak excuse, because then what happens if someone uses it all the time and gets used to it, but it is the only real reason I can imagine that there would be any trouble with seeing with it.

As an added advantage on an AoE silence, you could have the ultrasound track the center of it, which might be where the mage is, and just shoot for that.

"Weak excuse" is right. I have an adept in my game with the Enhanced Sense (Ultrasound) power, so I would think she'd be quite accustomed to using ultrasound.

Unless someone suggests a better idea, for firing at an invisible enemy, I'll go with the same penalty as firing in full darkness: a -3. I'll also skip making the character use Intuition instead of Agility.

Even though such a penalty seems odd considering how great ultrasound seems to be based on the description, I'll go with it since I don't want ultrasound to be the end-all vision type that everyone takes because it's the best of the best.

Well, at 100Khz (about what diagnostic ultrasound uses) sound has a 3mm wavelength. My impression is you can't typically build an active imaging system that offers finer resolution than the wavelength of the probing signal, but there's (calculation intensive) tricks that allow it (synthetic aperture radar does exactly that, for example) which might be practical in a Shadowrun setting. And "textures" can mean many things; you'd be able to tell office carpet from bare concrete based on how much and in what manner sound bounced off it, for example, without resorting to artificially enhanced resolutions.

The penalty for using Ultrasound in the dark (or only using ultrasound) might be appropriate even to expereinced users. The bulk of the human environment is oriented around visual cues. Echo-location simply is not equally useful, and a blanket penalty (instead of lots of situation specific ones) seems the easiest way to handle that.

A wierd tip on the textures thing- because the wavelenghts are similar to those of rather common real world physical features, its theoretically possible to construct an "ultrasound hologram". To normal vision, it might look just like a stucco wall, but hit it with the right freq of ultrasound and it bounces back a full 3d ultrasound image, or is just really confusing. If you had specially designed clothing with a very rough, sound reflective surface texture, it might be able to use this effect to confuse your ultrasound image enough that the user couldn't peg your actual location / body shape. If we actually had such senses, you might even see "paintings" done in such a fashion, the artist working in plaster with a set of "combs" with various tooth shapes / spacings. Pretty sure I read a sci-fi story once that had such an artform in it.

If a person is standing behind a pillar that completely blocks line of sight to him, would someone with ultrasound vision be able to "see" him by using only ultrasound?

No, because the ultrasound can neither go around nor through the pillar. Thus the person would be quite hidden from ultrasound.

No. Not unless the pillar is made of something sound can pass through. MAYBE you could see a "mirror reflection" of what's behind the pillar off a very smooth, hard nearby wall surface.

You'd mostly just see through things you already expect noise to pass through- mesh, screens, thin hanging cloth, paper walls, etc. And even then, high frequency sound doesn't pass through stuff as easily as normal sound- that's the whole reason its good for imaging!

Just treat it like normal vision that can't see images or through windows, and you'll save your GM a lot of headachey "what if" situations.

Thank you, Karoline and Mongoose. I understand a lot better how ultrasound works. Or at least how it could work in a reasonable fashion in the game.

For the record, I am the GM, which is why I'm wondering all of these things so that I know how to rule on them.

Perhaps something akin to sonar and echolocation?

That's exactly what it is.

It's not the best of the best. Ultrasound becomes quite useless for tracking moving targets at distances beyond about 170 meters due to the sound velocity of 343 m/s and the signal delay.

That's probably where the vision mods are really coming from: signal delay. At short distances things will be close to where they were, but I could still see that fractional second difference mattering when you fire a gun.

This. The detection of textures with ultrasound is not wavelength-dependent, because the diffraction of the longer wavelength pressure wave by the small details of the surface are what produces the information used to detect the texture, in the same way that a big wave hitting little rocks will produce lots of small waves, not a monolithic reflection of the large wave itself.


I would certainly agree with this assessment, provided the ultrasound were being processed as echolocation: in other words, as an auditory sense [the way the blind navigate]. However, isn't the ultrasound system - as well as the Radar system - in Shadowrun simply taking the information from the echolocation and producing a wireframe overlay which is processed visually?

I also agree with what was said upthread about using differences in visual input and ultrasound input to highlight possibly invisible objects. This could be done in "hardware" or "software," and should have some additional cost, but would quickly just become part of the standard package, as optional features tend to do.

Think bats, man.

My point was that sonar is a word for "like radar, but with sound."

And not just bats, but dolphins, most whales, shrews, and a few species of birds.
(Note: megabats don't have echolocation, except the genus Rousettus)

...which does its echolocation in a somewhat idiosyncratic way. Rousettus has been a great asset in studying both convergent evolution and echolocation. Nice reference.

Well, so an anti-ultrasound stealth sound is possible; either by looking confusing, or absorbing more sound than normal.

The effects of Silence and similar spells on ultrasound used to be clearly spelled out. Is this no longer true?

It looks like this was taken over by the "Sound Barrier" spell on p171 in Street Magic. I can't find a rule that allows Silence/Hush to affect Ultrasound. It might be buried somewhere. *shrugs*

Sound Barrier: "A variant of the Silence spell (p. 202, SR4), Sound Barrier creates a perimeter of silence around the area of effect (rather
than creating a mass area of silence). Those inside cannot hear outside noises but can hear sounds within the globe and vice versa. Only sounds crossing the border are affected, in the same manners as the Silence spell. This spell also affects technological devices, infrasound, and ultrasound."

Still, even using a "common sense" ruling, a mage using a Silence spell would probably show up as a blank spot in the ultrasound. The fact that there's an area that appears as a dead zone in the visual overlay might look suspicious, depending on the sophistication of the ultrasound system.

Ultrasound for a metahuman naturally would probably look something like this:
http://209.85.12.231/670/83/upload/p3438696.jpg
(Original Version of the photo: http://209.85.12.231/670/83/upload/p3438699.gif )

It would probably not look like Dare Devil's interpretation (which I think many runners think of it as in some way, even without thinking of DD):
http://www.awn.com/files/imagepicker/1/hou...vil_shadoww.jpg

That said...some kind of future-tech equipment that using computed ultrasound imaging would probably look something like long-range versions of what we see today as 4D ultrasound in utero imaging:
http://www.3d-4d-ultrasounds.com/images/ga...efore-after.jpg

Basically...something that looks close to clay in shades of bronze with some really dark odd black spots where the sound isn't picking anything up quite right, and probably a little worse than the last image due to range. But if it's future-tech, it wouldn't be that much worse.

However, natural ultrasound would probably look worse and much more like the first image, but possibly with a 3 dimensional depth and feel much more like the 4D imagery (the last link).

I've always thought of ultrasound vision just like the screen shown on those pregnant women ultrasound device. You can see shapes, but hardly any detail.

I think that daredevil vision is more like what you would get from ultra wideband radar (which can see through stuff).

And someone mentioned an image lag due to the 'slow' speed of sound, but I can't really buy that because bats use echolocation to catch insects in flight, so they must be fairly darn accurate, though I suppose that is at 'melee' ranges.

I guess it is a complimation of all these problems. A slight lag, unused to the vision, and various other small problems. I suppose this is something along the lines of why thermographic vision has a bit of problem in complete darkness (as I recall), that and a mechanical standpoint of not wanting one type of vision to be perfect in all situations.

Insects in flight can be fairly easy to track even when you're a mere human (we don't have enlarged audio processing centres in our brains). The bats can probably follow insects in flight using the sound of their flight apparatus alone. The bats can also predict where the insect will be, head for that, and adjust their estimates as they get new information. Hybrid approaches are always superior.

The classic images of prenatal ultrasounds are primitive compared to current technology, not to mention by 2070 technology levels. We've had diagnostic prenatal ultrasound for about 40 years, with only changes in resolution. The amount of detail that you can get from current ultrasound images is pretty amazing. It's the lack of color cues and artifcating that is disconcerting. I imagine that by 2070, the overlay will also have a "predicted" color or various color schemes (like current colorization techniques used in movies today... see the wikipedia article on film colorization for details).

That would have to be one hell of an ultra wideband radar to come out with anything more than spec representations.
Current UWB radar's that we make are only able to give top-down views with dots representing highest concentration of static in pattern groups of interest (most often human).

UWB is better used for things like cross-talking wireless communication systems rather than imaging systems.

.
A common fly flies around at 4.5 miles per hour.
The speed of sound is 761 mph.
The average rifle round speed is a little more than 2,000 mph.
Boxer's/MMA/Martial Arts punching speeds can reach around 20 to 30 mph.

So really...you're only lag here is something around 761 miles per hour.
There's really no lag aside from that.

Basically...anything traveling faster than just under 1/4th of a mile per second, (1,100 feet per second).
Now...here's a reference for that...
The following imagery is a guy that's holding a sign up of how far he is away.
On the left is a close up of him, and on the right is the actual view of him from that distance.
100 feet
http://www.prisonpolicy.org/images/geograp...ent/w01_100.jpg

250 feet
http://www.prisonpolicy.org/images/geograp...ent/w02_250.jpg

500 feet
http://www.prisonpolicy.org/images/geograp...ent/w03_500.jpg

1000 feet
http://www.prisonpolicy.org/images/geograp...nt/w04_1000.jpg


And you have to move that last distance in one second (or be capable of doing so) for you to move faster than ultrasound would pick you up.
As far as people go...that's just not going to happen.

You can't even get thrown objects to move faster than that.
Bullets are about the only things, but hell...even sighted folks have it hard against those things.

Arrows aren't even faster than you would be able to "see"; compounds can travel around 300 feet per second, and regular bows are around 170-190 feet per second.


But it's ultimately about speed of frequency and your brain's visual processing capacity and acumen...not really the speed of sound.
Human brains clock around 60Hz a second on average (slightly higher among some forms of depression and mania status brains).

And for frequency, our idea of sound (including our idea of the speed of sound on a day to day level...like the car door that we see close across the parking lot and then hear the sound of fraction of a second after) is based on a 15 to 18000Hz frequency level on average.

A bat, however, is running on around 80,000Hz+

So, if we just slap ultrasound onto someone that didn't mutate into having it, then it would be running pretty crappy with around a 78-99% decrease in cyclic rate of resolution.



Well...that all depends, I think, on what we're talking about.

But tech-wise, I would say it's well enough accurate representation in SR.
Natural versions in metahumanity...no idea, like I said above...I can only guess because the human hearing range isn't tailored for something like that and neither are our brain's processors...it's hard to imagine a human-like being that runs fairly alien to how humans run...visual complemented by audio, rather than audio for sight.

I'm not even sure such a "human" mutation would inherently have a talking capable tongue.
It wouldn't have much use sense sound is being used for sight and not talking...talking would be better done in high frequency pitch shifts that create visual patterns for communication.

So yeah ... big question mark on that natural version.

Ok, my bad, I should have mentioned SOTA prenatal ultrasounds devices. I've seen one of them and they already have a fine resolution, but then again, those devices work like a "beam" showing just a small image. If you put that into an actual vision, things could get complicated, as you would be capable to see inside people as well. Also, I think that ultrasound vision and echolocation work on different principles, don't they?

I beg your pardon, but if it's a "beam" showing a small image, then you have not seen one of the state of the art ones. You've seen a recent consumer model version of the traditional diagnostic prenatal ultrasound machines. It's superior to the ones that were built in the 60s obviously, but works on similar/same principles. Diagnostic ultrasound used to see prenatal images is different from ultrasound used as a visual overlay or producing images. For one thing, the range is a lot farther, and it's not used to look "inside" an object. Even then, diagnostic ultrasound for prenatal images has recently come a LONG way and can create images of the whole contents of the uterus in one pass.

Wrong approach. I was speaking of targets more than 170 meters away. The sound needs about 0.5 seconds to get there and 0.5 seconds to get back. A professional sprinter can run more than 10 m/s. Even an untrained person will be several meters away from the spot the display's showing him.

You can see what's inside a person with echography because the emitter/recevier is touching the body. It won't work that way with ultrasound sight because the sound waves will bounce on the air/body interface (different densities).

Ultrasound sights have a significant drawback : it is an active sensor, and as such it can be detected (with the proper sensor) farther than it can detect something.

So...you're saying there's a problem of someone running at me when it will take 17 seconds for them to reach me?

Bats (as a species) can fly up to speeds of around 60mph...that's 26 m/s (almost 27).
Now...that's much faster than the sprinting 10m/s person; actually...it's 160% faster.

So...if echolocation was so poor at fast moving objects, then how do we explain bats flying so fast that they would cross the 170 meter distance 11 seconds faster than the runner without smashing into things while doing this?

It's because they have shifting pulses.
Their Hz rates change dependent on which click type they are using, and visa verse.

They have one for widely sweeping the area, they have one for close range, and one for constant pulsing in general or average Hz.
Basically...the difference is like our vision of taking in an entire view (opening the peripheral), looking in our focal length, or just our general sight while doing things like walking.

A bat, for instance, can increase to roughly one click pair every 30ms.
The full Hz range is between 20Hz up the previously mentioned 80kHz.

That means that with the man running 10m/s idea, the bat would track him every 0.3 m/30ms.

This is because you don't just start sending a pulse only when something starts moving...you are always sending pulses, so when something is there (like a man waiting to run at you from 170meters), you already get that info and if the next time you see them in ultrasound is at 80 meters for some odd reason, then you'll shift to a higher frequency and faster pulse rate to catch up to the speed of the runner.

This is what bats do.
It's not about traveling faster than the speed of sound (or rather, not really), it's about putting the waves out before an object reaches the predicted area they will be in, that way they will hit one of the waves and bounce it back as they approach (or the opposite).

This creates a system by which each new identifier wave fuels a switch to a new click rate and higher frequency as one gets closer to the object, and lower click rate with a lower frequency as one gets farther from the object.

This is also because lower frequency maintains stability at longer ranges better than higher frequency, and higher frequency moves faster than lower frequency at a more rapid succession (meaning, more data feedback).


Now...if we're talking about ultrasound goggles...then if the goggles don't try to imitate this volatile pulse and frequency concept that bats use, then yes indeed...what you are talking about would pose some problems.

So...in a sense...I suppose one could say while the natural version would most likely have lower resolution than the technological version, the amount of object information would be greater and more accurate than the technological version.

My understanding is that he was saying that echolocation is poor for having an accurate position on a distant moving object. The closer something gets, the smaller the lag gets, to the point of being negligible.

A bat gets fine with that because it needs to be really accurate when things are close to it (an insect to catch, a predator to dodge, a wall to land, an opening to fly through...). At longer ranges the inaccuracy created by the return time doesn't matter because a general perception is all what the bat needs.

But we human sometimes need more : imagine trying to shoot a a gun out of tha hand of a guy 100 m away with only ultrasound sighting : you "see" the target not where it is, but where it was 0.3 seconds before, making accurate placement of a bullet a matter of luck as much as skill.

You can probably also get some speed information through Doppler effect.

An excellent treatment of echolocation for the layman is available in the second chapter of The Blind Watchmaker, available through the miracle of the internets here.

This.

I suppose if you really want to account for the penalty in a more realistic manner, you'd apply the distance penalty at 1/5 or 1/10 the normal distance (eg. instead of -1 at 300 meters, you're looking at -1 at 30 meters).

Of course wide bursts will enhance your luck. But yes, that's my point.



Actually I'm saying there's a problem aiming a gun at a moving target that stays constantly ahead of where your display's showing it.

Or just have them roll using Intuition instead of Agility.

Ah...I wasn't thinking outside of the box there.
Gotchya.

In that case, yeah, natural based ultrasound would probably have some serious issues.
I'm not aware of any echolocation animals on the planet that even play with object trajectory.

In this kind of situation, it would be more advantageous to have technological based ultrasound. Then it could help overcome this difficulty by computing, and displaying corrective measures for aiming. But it would be a piece of technology made for normally sighted people.


That's something else I didn't bring up earlier that would definitely impact things like shooting; naturally developed ultrasound wouldn't necessarily output to a sighted display at all. Instead it would just require information to be ideogramed and translated into an array of vibrational occurrences.

Essentially, there's no guarantee they would even be capable of shooting something 10 feet in front of them as their senses aren't developed for object trajectory of those purposes.
It's developed for things as they relate to their body and it's speeds.

So overall, they would probably make lousy shots, and horrible throwing sports players.
They would be better at melee than shooting.

On the other hand, we don't know if the software portion of the ultrasound sensor compensates for all this in some way. Maybe there's a doppler ghost that is superimposed on the overlay, or maybe it just automatically adjusts the images based on predicted values. A large part of the reason that echolocation works for bats (or binocular vision in humans, for that matter) is that their brains do a lot of post-processing to the "images".

Aren't the ultrasound 'visual' penalties for smoke/fog/rain? Not actual light differences? I dunno, fog and rain do tend to distort/dampen/absorb sound. I haven't spent enough time in buildings/areas full of smoke to know if it does the same, but, I thought the penalties were for sound diffusion/loss.

The distance penalties you all have discussed do make sense though.

Edit:
Hmm. Just looked, you do get penalties for darkness/partial light. That makes no sense to me. Yeah, must be the lack of corresponding visual picture to overlay.

I don't know if I understood correctly what you meant, but animals are capable of "calculating object trajectory. If you take a look at Fundamentals of Physics, volume 2, 6th ed. by Halliday, Resnick and Walker, chapters 17 and 18 both show ho scorpions and bats hunt using sound to locate their preys.

Bats have to send out 200 pings a second in order to actually catch their prey, and at a decreasing amount of sound energy (i.e. the buzz doesn't travel as far). That's a pretty large amount of data for determine a close range "collision."

There's no way you could use ultrasound "vision" at that high of a frequency in order to view targets out beyond a few meters.

Searching for prey, bats ping around 10-20 times a second, which is enough to locate a direction in which to travel in order to "close distance" with the target and use the higher frequency buzz necessary for catching the insect.

Yeah, that's not what I meant.

Object trajectory play is like throwing a ball, rolling a ball to another, or catching the same.
I'm not aware of behavior in bats that shows that they have the ability to track predicted trajectory like we do when we throw something to someone else.

I bring that in because it's similar to shooting at something...the bullet has nothing to do with you physically and is it's own object that will not be with you when it reaches the target.

This is highly different than tracking a prey with sound.




Draco18s;
If you scan back a bit through the thread, you'll see a couple large posts on my part that go through a decent depth of bat statistics, of which, the ones you are accounting for are cited.

That 200 clicks should be noted as only when they are close to their prey...it's not constant, and that's key.
Look back some where I talk about the three categories of frequency and click count that bats use for various range and purposes.

Consider this.

If ultrasound imaging was the bee's knees, why isn't it used more often today? Especially by the military. Instead we only ever really see it as pretty shoddy imaging with sonar or for looking inside an expecting mother. I imagine it'd be really easy to defeat if it ever became popular, too. All you would have to do is learn what frequency or frequencies the enemy is using, then spend a buck fifty on a transmitter that throws out random noise at the same frequencies.

Yep.

I've commonly wondered why magicians don't counter by just this effect itself instead of making sound barriers.
It's far more simple and more effective to act like (can't remember the exact name) a particular fancy moth out there that emits a high frequency that's not even the same as the bat's..it's just high enough to screw the bat up by a large margin.

It's equal to a flashbang for ultrasound.
In fact...that would be a great counter measure in it's own right.

You could even have the ultrasound flashbang span multiple frequencies with multiple cyclic rates of pulsing's, just to make sure to catch as many people as possible.

On any frequency you can't hear, it would probably just sound a lot like a bug zapper ticking at varying speeds.
But to the affected, it would be a hellish experience.

Sound barriers are a little more useful than just defeating ultrasound.

Oh well yeah, but I've seen plenty of mages just throw up sound barriers as a block to ultrasound, that's what I was saying.
It's easier to defeat ultrasound than they were making it...that's all.

I just watched this DailyPlanet show on Discovery that featured a story showing the trying to locate land mines, it stated and showed that metal detectors were less effective than sonar in detecting the objects in the ground that were potentially dangerous because the sonar could figure out the shape, distance to, and contents of the landmine.

Here is a link: http://watch.discoverychannel.ca/daily-planet/#clip240114

Considering that, wouldn't there be some really interesting uses for ultrasound in the SR world? Lets see what is in the walls or under people's clothes/in body cavities?