Backscatter Vans -- Coming To Your Neighborhood Soon?

[Kaylee]

Backscatter machines go mobile --

Because of the power and mobile nature of the vans, the Department of Homeland Security and the United States military are starting to buy up quite a few of the vehicles, planning to utilize them in all sorts of areas.

According to AS&E, the vans can scan through a vehicle in about 15 seconds. Furthermore, the equipment within the vehicle can be operated remotely from up to 1,500 feet away. Considering the plain-looking aesthetics of the vehicle, law enforcement and government agencies could certainly place it wherever they want, without fear of being noticed.

Of course, issues of privacy are being voiced already. Considering the overall effectiveness of the truck, and the fact that it can seemingly scan through most everything (including some buildings and, yes, clothes) to find whatever it is the operator is looking for, people are raising their voices to the fact that their overall privacy is potentially being violated. Still, others are questioning how much radiation a truck of this size, with the equipment inside, is releasing on a daily basis.

Company web site with pix:
http://www.as-e.com/products_solutions/zbv.asp


I can envision a future where everyone, men and women, Muslim's and non-Muslim's all wear lead-lined burkas to absorb the radiation. Burkas, not just for the harem anymore!

Seriously, I don't want to be blasted with ionizing radiation and I'd really like to see this technology made illegal for everyday casual use.

 

[sadhatter]

We all like laws, and we all want the laws enforced, but there seems to be a point at which we say " this law is being enforced too well.". Corrupt people will use this technology for corrupt reasons and non corrupt people will use it for non corrupt reasons. To blame the technology for being good at its job is just silly.

As far as the radiation, that is a separate issue, but the ongoing trend of people to say " The law can't have the best technology available." , is something i find silly. Don't like a law? Work to change it. That may mean Dr. Smith will have to risk his career actually vocally supporting legalizing pot, instead of buying it on the side and hoping no one finds out. But isn't that the way the law should work?

 

[casebro]

Haven't they already required 'probable cause' for these kinds of surveillance?

But I suppose the radiation hazard has to be argued next, as punishment without due process?

eta: The same way an employer can be held for violating OSHA radiation protections?

 

[casebro]

Hey another thought: Are back scatter xrays used in medical imaging? Why or why not? How much radiation?

I tried a google, but nothing except 'backscatter ultrasound' .

 

[Delvo]

Are back scatter xrays used in medical imaging? Why or why not?

No. X-rays for medical images go through the patient and are detected by a sensor plate or large piece of film on the other side. Scattered radiation can leave the patient going in any direction, so it can hit any point on the detector plate, which makes the image foggy, so we actually try to minimize scatter. The radiation that's useful in a medical image is what went straight through the patient without getting scattered, so each point in the detector (and thus each point in the recorded image) corresponds to exactly one path through the patient from the emitter. That's what gives the image clarity and detail. Worse yet, whatever body part/surface the beam hits first produces the most scatter, so any information you could get from it would be primarily or even exclusively related to the relative orientation and distance of the patient, not to any traits of the internal structure. When you use radiation that's passing through the patient, you get information about what's inside, such as density and nuclear composition, instead of just whatever bit was closest to the emitter.

Here's an analogy in visible light. When you look at a smoke column coming from a forest fire from a mile away, you're looking at light that bounces off of the smoke's surface on the side facing you. That tells you the size and shape of the smoke column's outer surface on the side facing you. When you're on the ground below the smoke, you can't see that. But you can look at its shadows, where any light that you do see had to pass through the smoke to get there. That tells you where the smoke column is the thickest and densest, so you have some idea of its internal structure in three dimensions, including how the wind is blowing above you. The kind of information you get standing in the forest fire's shadow is the information you want in a medical setting; the kind you get by standing back a mile away and looking at the smoke is what they're getting with these scanners.

Given the fact that scattered radiation can come away from the scattering object in any direction, I'm curious how they can get any detail out of this kind of system. We do it fairly easily with scattered light because we can focus light, but there aren't lenses for X-rays; a lead cover with a pinhole would be as good as an optical pinhole, though. Fortunately, they don't need a whole lot of detail for this application, I suppose. For the amount of detail they do need and get, putting the subject really close to the detector surface would help make the fog less hopelessly blurry, and putting the subject really close to the emitter would too. But that's easiest to do with only a small area to be scanned and a small sensor to pick it up, and with these scanners, we're talking about scanning a large object, and the detector would seem to be the size of a wall. I suspect that they have an emitter that moves vertically and horizontally behind the X-ray-transparent wall surface, to keep it as close as possible to the body part being zapped. That would also allow overlapping passes, where the emitter zapped the same part from different angles, to be compared in the computer.

 

[Fnord]

One possible solution:
_{(Ye Olde Tinfoille Hatte)}​

 

[casebro]

Delvo, I though they might be used for some other imaging. Like skin cancers or such, something near the surface. Or maybe at a different frequency, or something related but different, like MRI.

 

[WildCat]

Remember, you voluntarily leave your house. You don't have to go outside.

 

[Kaylee]

Haven't they already required 'probable cause' for these kinds of surveillance?

But I suppose the radiation hazard has to be argued next, as punishment without due process?

eta: The same way an employer can be held for violating OSHA radiation protections?

The closest thing I can think of is that New York City (and I assume other US cities) has surveillance cameras on many of it's streets. I think legally its considered OK because people are not given the same expectation of privacy on a public street that they are given inside their homes, offices, cars and trucks. (4th amendment rights)

However backscatter machines take public surveillance to a whole 'nother level. The pictures I've seen on the net can see through our cars and the walls of our homes and office buildings. And I would assume of course that they can still see through our clothing like the ones used in the airports do. Since legally we currently still have the expectation of privacy within our clothes, cars, homes and offices -- I expect that the use of backscatter vans on our city streets will be challenged in the courts.

As for suing the federal government --

In the United States, the federal government has sovereign immunity and may not be sued unless it has waived its immunity or consented to suit.

The rest of the Wiki article goes into some of the few exceptions to that rule. It appears that the short answer is that for most people in most situations, don't count on suing the US Federal govt. unless its over a violation of constitutionally guaranteed rights.

In regard to arguing against radiation hazard as punishment without due process (5th amendment rights). That's interesting, if we can't halt the new machines on 4th amendment issues, perhaps we will have better luck with the 5th or even 14th amendments. Can health be considered a person's property? Also, some articles I've read have said that some people have so little tolerance for ionization radiation that they have a 1 in 5 chance of getting cancer if exposed to backscatter machines ( such as people with the BRCA1 and BRCA2 genes for example). It could be argued that those people are being constitutionally deprived of their right to life -- literally. The 14th amendment includes this sentence:

All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State [ed. bold] deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.

The backscatter machines' health risks are controversial. Based on what I've read so far, some very reputable scientists don't think they are safe as they are being used now. I'd be happy to join anyone in the Science forum who wants to discuss the health risks of the machines.

 

[Kaylee]

Remember, you voluntarily leave your house. You don't have to go outside.

Yep, I remember! You were the first to say that in the other backscatter machine threads. You win.

 

[Checkmite]

Since legally we currently still have the expectation of privacy within our clothes, cars, homes and offices -- I expect that the use of backscatter vans on our city streets will be challenged in the courts.

Maybe; maybe not. Police use of drug detection dogs who alert to scents from vehicles (thereby establishing probable cause for a physical search) has been challenged, and was upheld by the courts - IIRC, basically the reasoning is that while you have an expectation of privacy inside your own car, that privacy does not extend to scents that leave your car and travel into the open air around it; they're fair game and can be used by police to establish probable cause. I imagine the government might argue a similar case with these machines; you don't "own" the radiation that emanates from or bounces out of your house, no matter how it got there.

 

[Delvo]

The pictures I've seen on the net can see through our cars and the walls of our homes and office buildings.

Such images are fake or mislabeled.

For one thing, even just the distance you'd be away from whoever you're trying to look at in a case like that, compared to the distance of an airline passenger away from the scanner's wall, introduces problems. It would greatly increase your power requirement (inverse square law). Because scatter can go in any direction, there's an inherent lack of image clarity and detail that only gets worse with distance. And the distance puts more air between you and your target, and even air can add more absorption and scattering to make your hazy image hazier. And even that's if you're only shooting through nothing but air at a distance comparable to the distances involved in trying to scan someone, like outside or in some kind of open-air architecture (with which you could see inside optically anyway). When you consider that buildings and vehicles are enclosed, this idea gets so far outside the physically possible it's absurd.

For the radiation in these devices to bounce off of people's skin and not go clear through the people, it has to have rather low power, which would make it unable to get through buildings' walls or vehicular sheet metal at all. It might get through window glass, but even then only with significant losses to absorption and additional scattering even there, and it only gets worse if the window has a metal screen in it. You might be able to make X-rays powerful enough to get through some of these obstacles, but then they would not be bouncing off of human skin. (And you might alert people to the fact that something was up if your beam started causing immediate damage or a sharp temperature increase in whatever it was hitting.)

And if you don't think the controversy over these machines has caused people to start making fakes and labeling them as if they were airport scanner images, just download some of the images associated with articles & blogs about it, like this one and this one, invert their colors, and figure out for yourself how they were really made. (The same search through which I found those also showed me some of the vehicle & building images I guess you're talking about, and they have their own "tells" that reveal their fakery, but just not as easily as those... unless the name "Alex Jones" associated with some of them is enough for you. )

 

[Sir Robin Goodfellow]

Maybe; maybe not. Police use of drug detection dogs who alert to scents from vehicles (thereby establishing probable cause for a physical search) has been challenged, and was upheld by the courts - IIRC, basically the reasoning is that while you have an expectation of privacy inside your own car, that privacy does not extend to scents that leave your car and travel into the open air around it; they're fair game and can be used by police to establish probable cause. I imagine the government might argue a similar case with these machines; you don't "own" the radiation that emanates from or bounces out of your house, no matter how it got there.

If I recall correctly, the courts up here have said that a dog alerting to a scent is not probable cause for a search. I'm not sure of the court's reasoning. I know it's not the same down south, though.

 

[Kaylee]

Maybe; maybe not. Police use of drug detection dogs who alert to scents from vehicles (thereby establishing probable cause for a physical search) has been challenged, and was upheld by the courts - IIRC, basically the reasoning is that while you have an expectation of privacy inside your own car, that privacy does not extend to scents that leave your car and travel into the open air around it; they're fair game and can be used by police to establish probable cause. I imagine the government might argue a similar case with these machines; you don't "own" the radiation that emanates from or bounces out of your house, no matter how it got there.

With dogs, no privacy is lost unless they smell contraband. At that point there's probable cause for a search. Before that point, our privacy is still protected against other people, albeit not dogs.

With the backscatter machines, people (not dogs) are monitoring what's on the screen and so they are seeing everything in the passing cars and behind the building's walls, including homes and offices (and presumably under our clothes as well), regardless if there is contraband or not and before there is probable cause to search the various individuals.

I don't know if my interpretation would hold up in court -- but this is one of the main practical differences I see between using dogs and back scatter machines for surveillance. The other main difference is the effect on people's health.

So, I think this is a different situation and that arguments used in the past won't apply. But I don't doubt that the attorneys for the govt will try to use them.

 

[WildCat]

Yep, I remember! You were the first to say that in the other backscatter machine threads. You win.

I can't resist...

 

[Kaylee]

Such images are fake or mislabeled.

For one thing, even just the distance you'd be away from whoever you're trying to look at in a case like that, compared to the distance of an airline passenger away from the scanner's wall, introduces problems. It would greatly increase your power requirement (inverse square law). Because scatter can go in any direction, there's an inherent lack of image clarity and detail that only gets worse with distance. And the distance puts more air between you and your target, and even air can add more absorption and scattering to make your hazy image hazier. And even that's if you're only shooting through nothing but air at a distance comparable to the distances involved in trying to scan someone, like outside or in some kind of open-air architecture (with which you could see inside optically anyway). When you consider that buildings and vehicles are enclosed, this idea gets so far outside the physically possible it's absurd.

For the radiation in these devices to bounce off of people's skin and not go clear through the people, it has to have rather low power, which would make it unable to get through buildings' walls or vehicular sheet metal at all. It might get through window glass, but even then only with significant losses to absorption and additional scattering even there, and it only gets worse if the window has a metal screen in it. You might be able to make X-rays powerful enough to get through some of these obstacles, but then they would not be bouncing off of human skin. (And you might alert people to the fact that something was up if your beam started causing immediate damage or a sharp temperature increase in whatever it was hitting.)

And if you don't think the controversy over these machines has caused people to start making fakes and labeling them as if they were airport scanner images, just download some of the images associated with articles & blogs about it, like this one and this one, invert their colors, and figure out for yourself how they were really made. (The same search through which I found those also showed me some of the vehicle & building images I guess you're talking about, and they have their own "tells" that reveal their fakery, but just not as easily as those... unless the name "Alex Jones" associated with some of them is enough for you. )

You do raise interesting points, some of which I've been wondering about.

However, so far the only backscatter van pictures I've looked at have been on the manufacturer's web site. (American Science & Engineering Inc.: http://www.as-e.com , the link was also in the OP). The only claims I've read have also been on the manufacturer's web site. Presumably they have a strong motive to not misrepresent what their equipment can and can't do. After all, they not only sell to the Homeland Security Dept. but also to agencies in foreign countries and presumably would be expected to live up to any sale's terms of contract. A stereotypical used car dealer attitude would probably just get them into a lot of serious trouble.

So even though I have a lot of questions about the technology -- I'm inclined to believe that it does work.

Did you have a chance to look at the manufacturer's web site?

 

[Drachasor]

Maybe; maybe not. Police use of drug detection dogs who alert to scents from vehicles (thereby establishing probable cause for a physical search) has been challenged, and was upheld by the courts - IIRC, basically the reasoning is that while you have an expectation of privacy inside your own car, that privacy does not extend to scents that leave your car and travel into the open air around it; they're fair game and can be used by police to establish probable cause. I imagine the government might argue a similar case with these machines; you don't "own" the radiation that emanates from or bounces out of your house, no matter how it got there.

There's a big difference between scents or radiation (in the case of light or nuclear isotopes) from an area and beaming radiation into an area to see what would otherwise be invisible under any condition.

 

[Dan O.]

Does this thread have anything to do with pulsed 3.6THz quantum cascade lasers and synchronous microbolometer imaging arrays?

 

[Kaylee]

Does this thread have anything to do with pulsed 3.6THz quantum cascade lasers and synchronous microbolometer imaging arrays?

I think THz is in between the microwave and infrared range of the electromagnetic spectrum. The X-ray range of the EM is higher up. See diagram at:
http://en.wikipedia.org/wiki/File:EM_Spectrum_Properties_edit.svg

So ... just based on that alone, I would say the answer is no.

 

[Dan O.]

I think THz is in between the microwave and infrared range of the electromagnetic spectrum. The X-ray range of the EM is higher up. See diagram at:
http://en.wikipedia.org/wiki/File:EM_Spectrum_Properties_edit.svg

So ... just based on that alone, I would say the answer is no.

I think the name may be a reference to the property of seeing through layers more than the spectrum of the energy source. Until I see a better explanation of how these things actually work, i'll continue to go by what i've dug up so far. If it was actually using x-rays, I would have expected someone to have gone through security with an x-ray dosimeter and report what the exposure is.