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Government Lab Uses Smartphones To Measure Gamma Ray Exposure

samzenpus posted about 7 months ago | from the hulk-phone-is-strongest-there-is dept.

Science 105

KentuckyFC writes "Back in 2008, Slashdot reported that researchers were developing ways of turning cellphones into radiation detectors. Since then a few apps have even appeared that claim to do this. However, convincing evidence that they work as advertised is hard to come by. Now government researchers at Idaho National Labs have created their own app that uses an ordinary smartphone as a gamma ray detector, put it through its paces in the lab and published the results. The pixels in smartphone cameras can detect gamma rays in the same way as they pick up visible light. So when the lens is covered, the image should reveal evidence of gamma ray exposure once other noise has been removed, such as that from heat and current leakage. These guys have tested several types of Android smartphone with a variety of gamma ray sources at various different doses. The researchers say the phones give a reasonable measure of radiation dose, can detect the direction of source (by comparing the measurements from the front and back cameras) and can even measure the energy of the gamma rays by measuring the length of the tracks that appear in the image. While the results do not match the quality of bespoke detectors, that may not matter since in many circumstances cellphones are likely to be the only sensors that are available. That could be useful for emergency services, air travelers wanting to monitor their extra radiation dose on routes over the arctic and people who live in areas with a higher than average background radiation level."

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My iPhone is getting Angry! (4, Funny)

jellomizer (103300) | about 7 months ago | (#45940629)

You don't want my iPhone getting Angry!

Re:My iPhone is getting Angry! (0)

happy_place (632005) | about 7 months ago | (#45940893)

So can the phone detect the radiation it is generating and solve that endless debate as to whether cellphones are causing brain tumors?

Re:My iPhone is getting Angry! (2)

amRadioHed (463061) | about 7 months ago | (#45943221)

I don't think there was ever any question that phones generate radiation, that is what the antennas are for. But this is for gamma rays, if your phone is generating any of them then something is horribly wrong.

Ionizing vs. non ionizing: (0)

Anonymous Coward | about 7 months ago | (#45946395)

The RF radiation that the phone produces is way lower in frequency than gamma. It is non ionizing, unlike gamma. Non ionizing radiation produces no chemical reactions and wont directly cause mutations as gamma would.

Re:My iPhone is getting Angry! (1)

NoNonAlphaCharsHere (2201864) | about 7 months ago | (#45941149)

"Don't make me android. You wouldn't like me when I'm android."

Re:My iPhone is getting Angry! (1)

noh8rz10 (2716597) | about 7 months ago | (#45941589)

Is that a Mystery Men joke?

Re:My iPhone is getting Angry! (1)

gstoddart (321705) | about 7 months ago | (#45941835)

Is that a Mystery Men joke?

Frac-u-later. ;-)

Re:My iPhone is getting Angry! (1)

jandrese (485) | about 7 months ago | (#45942921)

Indirectly, since the Mystery Men character was a parody of one of the most recognizable characters in comics [wikipedia.org] .

Re:My iPhone is getting Angry! (1)

Anonymous Coward | about 7 months ago | (#45942587)

my iPhone

They said *Smart*-Phones

Two words (2)

cold fjord (826450) | about 7 months ago | (#45940633)

HULK SMASH!!

Does sound like a neat idea. I'm hoping there won't be much call for it outside of labs though. I'm not a big fan of excessive radiation.

It's not a nuclear power plant (2)

h00manist (800926) | about 7 months ago | (#45940755)

Read again. It doesn't generate radiation. It's not a nuclear power plant.

Though if someone writes an app to turn the phone into a safe nuclear power plant it might be popular.

Re:It's not a nuclear power plant (1)

cold fjord (826450) | about 7 months ago | (#45940881)

It's not a nuclear power plant .... Read again. It doesn't generate radiation. It's not a nuclear power plant.

Though if someone writes an app to turn the phone into a safe nuclear power plant it might be popular.

The danger isn't what they propose to put in your pocket, the danger is what they are trying to detect! (Ignore the radiation leak, the cell phone poses no threat.)

A cell phone into a "safe nuclear power plant"? *_*

Re:Two words (2)

i kan reed (749298) | about 7 months ago | (#45940763)

You don't like the sun?

Re:Two words (0)

Anonymous Coward | about 7 months ago | (#45940869)

No. No I do not. I prefer the peaceful tranquility of night without a full moon.

Re:Two words (2)

cold fjord (826450) | about 7 months ago | (#45940925)

From what I hear gamma radiation come from more sources than just the sun, sometimes in dangerous dose rates.

But I'm intrigued, are you suggesting that solar radiation never poses a risk under any circumstances?

Re:Two words (1)

weilawei (897823) | about 7 months ago | (#45941347)

But I'm intrigued, are you suggesting that solar radiation never poses a risk under any circumstances?

Obvious trollbait is obvious.

Re:Two words (2)

NatasRevol (731260) | about 7 months ago | (#45941415)

Holy shit that's bad reading on your part

GGP - "I'm not a big fan of excessive radiation"
GP - "You don't like the sun?"
You - "are you suggesting that solar radiation never poses a risk under any circumstances?"
Me - WTF are you reading?

Medical marihuana is legal (1)

h00manist (800926) | about 7 months ago | (#45941625)

Smoking stuff in many instances is now legal. So lots of people are smoking stuff, including while reading /.

Re:Two words (1)

cold fjord (826450) | about 7 months ago | (#45941919)

You're either asking the wrong person, or not following the conversation.

Re:Two words (1)

i kan reed (749298) | about 7 months ago | (#45942103)

No, his summary is accurate. Maybe you didn't read what you wrote?

Re:Two words (1)

NatasRevol (731260) | about 7 months ago | (#45942247)

Like many other topics, cold fjord, you're on the wrong side.

Re:Two words (1)

cold fjord (826450) | about 7 months ago | (#45942411)

Which part, exactly? The part where I think it's a neat idea? The part where I hope it isn't needed much outside the lab - since it is intended to measure excess radiation, including in emergency situations? Or the part where I state I'm not a fan of excess radiation?

Are you suggesting I should be a fan of excess radiation and radiation emergencies? I'm curious.

Re:Two words (1)

NatasRevol (731260) | about 7 months ago | (#45944077)

Apparently, you have to have it spelled out for you.

First guy says I'm not a big fan of excessive radiation.
Second guy says you don't like the sun?
You say Are you saying the sun doesn't have excessive radiation?
Second guy is like, no I was saying that the sun does have excessive radiation
I'm like you're an idiot.

Re:Two words (1)

cold fjord (826450) | about 7 months ago | (#45944443)

Thank you for spelling that out. My post was the first one in that thread that you attribute to, "First guy." The second guy was confused in his reply since the question is detection of excessive radiation, not the sun. You don't really summarize my next point correctly since the point is that sun's radiation can pose a hazard, not that it is excessive. The post that I replied to was basically off topic. In summary, you've got it wrong. The one you should be complaining to and about is the other guy.

Re:Two words (0)

Anonymous Coward | about 7 months ago | (#45948409)

You only have to worry about excessive radiation when your cell phone's imaging censor starts to experience permanent pixel loss.

Headline is ambiguous (0)

Anonymous Coward | about 7 months ago | (#45940649)

It took me awhile to realize that the government wasn't using smartphones as equivalent *generators* of gamma rays for the purpose of radiation exposure testing.

convert smartphones to gamma ray guns (1)

h00manist (800926) | about 7 months ago | (#45940839)

Maybe someone *should* convert smartphones to gamma ray guns. In order to study the effects, of course.

Re:Headline is ambiguous (3, Funny)

Immerman (2627577) | about 7 months ago | (#45940873)

Really?
Student uses yardstick to measure classroom. Dang, we gotta watch out for all those yardsticks creating extra distance.

Re:Headline is ambiguous (1)

geekoid (135745) | about 7 months ago | (#45944725)

Well put.

Digital camera elements (3, Interesting)

i kan reed (749298) | about 7 months ago | (#45940661)

I've always wondered why we can't do simple infrared or ultraviolet examinations of things with our smart phones.

I have a sneaky suspicion it's because not all clothing is opaque in those spectra, but I like neat science toys, and wish my phone was a little more tricorderish.

Re:Digital camera elements (2)

cold fjord (826450) | about 7 months ago | (#45940807)

The sensing elements used in the cameras are designed for their purpose. They will generally have a limited range of sensitivity in terms of the wavelengths they detect. Different materials and sensor element designs may be needed depending on the wavelength, required sensitivity, and other aspects of the intended use and environment. Something that works well for infrared may not work well for UV detection and measurement. Doing it all uncooled adds other challenges.

Re:Digital camera elements (4, Informative)

Immerman (2627577) | about 7 months ago | (#45940915)

Actually most digital cameras are far more sensitive to infrared than to visible light - they actually come equipped standard with infrared blocking filters so that the visible spectrum isn't totally drowned out, and they *still* can usually see the wimpy blinking light on your IR remote. I think they're usually less sensitive to UV though.

Re:Digital camera elements (1)

Anonymous Coward | about 7 months ago | (#45941753)

The poster you replied to would be correct if you take the whole camera into consideration, instead of just the sensing element. As designed, which means including the IR filter, it will not do a good job of picking up IR (and UV typically sucks on cheap optics). That IR filter is not there because of being able to see through people's clothing, especially since I haven't seen such problems when removing such filters to make cheap IR laser diagnostics, but because your visible images will suck without in various situations. If you are building a camera that is meant to roughly reproduce what we see, then it sucks when unseen IR sources wash out part of your image, or the color comes out weird (e.g. extra red or extra blue depending on the particular camera). You could make filter out IR on a per pixel basis and have an extra set of pixels that are unfiltered, adding IR pixels to the typical RGB pixel mixes, but manufacturers of phone cameras must not expect much demand for that.

Re:Digital camera elements (1)

ceoyoyo (59147) | about 7 months ago | (#45941911)

Not far more sensitive. They are sensitive to IR, and do come with a filter to block it out, but they're not sensitive to very much of the IR spectrum, and not particularly sensitive to even that part, so taking IR photos is an exercise in low light photography.

Re:Digital camera elements (3, Insightful)

hubie (108345) | about 7 months ago | (#45942565)

Digital cameras are very insensitive to the IR. Silicon, which is what all commercial camera sensors are made of, loses its sensitivity around 1000 nm, so photons with a longer wavelength than that generally pass through undetected (they are most sensitive around 600-ish nm, which is something like orange light). On the other hand, if you look at the spectrum of light coming from the Sun, you get the most photons around that same 600 nm wavelength (how's that for coincidence?), but you also still have a whole lot of photons flying around with wavelengths of 1000 nm and less. Camera makers put IR-blocking filters on because the optics for the cameras are optimized for visible wavelengths, so IR wavelengths will not come to a nice focus. These IR wavelengths add image blur. Some people want to pop their IR filters off because it will make their camera more sensitive, which technically is true, but you'll make your pictures look blurry unless you do something else (i.e., filters) to restrict the wavelengths of light through your optics.

You also have to be careful when you talk about the IR that these cameras can detect. What you're really talking about is very deep red, or the first parts of the NIR (near infrared) region. Most people, when they hear IR, think heat signatures, but that is not what you're dealing with here. The thermal IR is much longer wavelengths, and you'll never see that with a silicon-based camera. In fact, pure silicon is very useful as a window material for IR sensors because it is very transparent to photons at those wavelengths.

Re:Digital camera elements (0)

Anonymous Coward | about 7 months ago | (#45944055)

The index of refraction of typical glasses and plastics versus wavelength gets flatter on the red end of the spectrum than the blue spectrum. 900-1000 nm stuff won't have much more trouble focusing than 600-700 nm stuff, unless you camera already struggles with focusing that end of the spectrum. And in my experience it works in practice and not theory, as even cheap optics on cheap cameras don't have trouble focusing 1064 nm when the filter is removed, at a couple megapixel resolution. Cheap cameras seem to suck at focusing in general at resolutions beyond that anyway, regardless of color.

Re:Digital camera elements (0)

Anonymous Coward | about 7 months ago | (#45944169)

it works in practice and not theory,

It works in practice and not ^just theory.

Re:Digital camera elements (2)

hubie (108345) | about 7 months ago | (#45944431)

I agree that most lenses will have no problem focusing 1000 nm. The problem is trying to focus across that whole wavelength range. Decent multi-element lenses are designed to operate best in the visible, and you will not get the same kind of performance near the NIR. I learned the hard way years ago after spending the effort to optimize the focus of a camera (using a decent-quality Schneider lens), I then put a NIR long-pass filter on and, until I finally had that forehead-slapping "duh" moment", I couldn't figure out how my focus got so crappy. Fortunately, the fix for me was to just re-focus the lens and the image looked fine. As you say, a crappy lens is a crappy lens, so the effect will be less noticeable with cheaper lenses.

Another thing working against the cell phone type camera as an IR detector is that the reason silicon is not very sensitive out in those wavelengths is that most photons with those wavelengths pass through and don't interact in the material. The way to make it more sensitive towards the IR is to have a thick detector substrate; however, especially with cell phone cameras, the design is to make them as thin as possible to cut down on detector noise.

Re:Digital camera elements (1)

Anonymous Coward | about 7 months ago | (#45940809)

And I wish my door opened automatically with a 'swoosh'ing sound. But neither one of these things is going to get either of us laid.

Re:Digital camera elements (1)

i kan reed (749298) | about 7 months ago | (#45940825)

You've clearly been dating the wrong women.

SciFi movie swishing doors = no sex? (2)

h00manist (800926) | about 7 months ago | (#45940865)

I am not sure the lack of a connection between swooshing doors and sexual attraction is clear. Can you elaborate.

Re:Digital camera elements (3, Interesting)

Lehk228 (705449) | about 7 months ago | (#45940845)

infrared and ultraviolet are intentionally excluded from cameras with filters so that the image recorded looks like it should, I suppose filters could be applied on a per pixel basis in order to make a 5 or more element R,G,B,IR,UV sensor, but the cost would be .... considerable

Re:Digital camera elements (2)

i kan reed (749298) | about 7 months ago | (#45940861)

Would it really be that much more than an RGB filter?

Re:Digital camera elements (1)

weilawei (897823) | about 7 months ago | (#45941417)

A filter removes a portion of something. You filter out things. Phone cameras don't use an RGB filter. That would defeat the point of having a camera. If we assume it takes 2 discrete filters to remove IR and UV, RGB filters would add another 3 (assuming we kept the same constraints, one per narrowly defined band, which we need not do in reality). Would it cost more to manufacture a sensor which detects all of them? No. They generally do that just fine anyway. Hence the filters. Would it cost more to have specific sensor elements detect different bands, for a multi-megapixel sensor? Yes.

Re:Digital camera elements (2)

Obfuscant (592200) | about 7 months ago | (#45941921)

A filter removes a portion of something. You filter out things. Phone cameras don't use an RGB filter.

Actually, they do. The standard single-chip image color image sensor uses what is called a Bayer filter array [wikipedia.org] of red, green, and blue color filters in a regular pattern, one filter per pixel. From this data, a color image is reconstructed by combining the color data from that pixel with the colors from the neighboring pixels. The dirty secret is that the resolution of a "megapixel" camera is thus much less because a nine by nine array of pixels is used to create the color data for each color output pixel.

Color sensitivity is often reported in the datasheet for the sensor. This [seekic.com] is a datasheet for a typical CMOS sensor, and the color sensitivity is shown on page 11. The individual sensitivity is due to the filters, the MONO data is for the sensor sans filter. CCD spectral curves are quite similar. The Sony ICX285AQ [alldatasheet.com] is an example. If you compare data sheets, you'll notice that the ICX285AL is identical to the AQ with the exception of the color filters, and the AL version is the monochrome sensor.

It would be interesting and not that expensive to create a different color filter pattern on the sensor to include IR and UV filters, but the use would be limited. Those who want IR images typically use the monochrome sensor and external IR pass filters, and UV is usually excluded by normal users by the use of a skylight or other UV cut filter. The dyes in the RGB filters are sensitive to the UV and will decompose over time, changing the color capability of the camera.

Re:Digital camera elements (1)

dunkelfalke (91624) | about 7 months ago | (#45949389)

You can use a Sigma DSLR with the IR/dust filter removed. Add an IR pass/Visible light blocker filter in front of the lens and you can make IR photos.

Re:Digital camera elements (1)

ceoyoyo (59147) | about 7 months ago | (#45941973)

I doubt it would cost more to make a five element filter compared to the current three element ones if it were mass produced. The problem is that camera sensors aren't really very sensitive to IR or UV, almost nobody actually wants that functionality, and it would reduce the effective resolution of your camera.

Re:Digital camera elements (0)

Anonymous Coward | about 7 months ago | (#45941843)

Apparently it is a pain to make the individual RGB pixels filter out IR on their own, instead designing the filters so they only exclude the other two parts of RGB being measured. Otherwise, they wouldn't need an external IR filter, and would just have integrated that into the Bayer filter on the sensor, even if it didn't have IR pixels. And the IR filters used on cameras aren't perfect, as you can still find weird colors when imaging some mildly incandescent items or arcs depending on the camera, so I would have to wonder if there would be a sacrifice in IR filtering ability to get it done on a per pixel basis.

Re:Digital camera elements (1)

i kan reed (749298) | about 7 months ago | (#45942121)

But I waaaaaaaaaaaaaant it. These practical constraints are no fair!

Re:Digital camera elements (1)

BadDreamer (196188) | about 7 months ago | (#45942627)

There are already RGB filters on the camera; the sensor only takes pictures in black and white, so an RGGB Bayer array is used to filter the light reaching each photosite. And since there are two G pixels per final pixel, one of those could be switched to an IR filter. That would allow for taking IR pictures (at lower resolution) or mixing in IR in the color photo.

Re:Digital camera elements (2)

Bite The Pillow (3087109) | about 7 months ago | (#45940871)

People use cameras to take pictures of visible light, so the demand for other spectra just isn't there. The simple digital devices have a filter film that can be removed, or replaced for night vision. They are not optimized for night vision so sensitivity is an issue. But it works.
Depending on where you got your camera parts, they may have a filter, or its possible to do math instead. But a film is cheaper as long as it stays in place
If you have one, replace it with thin black paper or other things.
As for why, smartphones are not designed to be user serviceable. But if you're a geek, anything's serviceable.

Re:Digital camera elements (1)

Tapewolf (1639955) | about 7 months ago | (#45940949)

I've always wondered why we can't do simple infrared or ultraviolet examinations of things with our smart phones.

I have a sneaky suspicion it's because not all clothing is opaque in those spectra, but I like neat science toys, and wish my phone was a little more tricorderish.

Actually, many digital cameras will pick up infra-red. Try sticking a remote control in front of one - depends on the camera, but a lot of them will show it lighting up.

Re:Digital camera elements (1)

gstoddart (321705) | about 7 months ago | (#45941085)

Actually, many digital cameras will pick up infra-red. Try sticking a remote control in front of one - depends on the camera, but a lot of them will show it lighting up.

Absolutely true.

A year or so ago I was having problems getting the remote for my new TV to work.

I ended up confirming the remote worked by pointing it into my digital camera and confirming I could see the IR being sent in a picture.

Once I confirmed that it was working, it let me narrow down the places I could be looking for my problem.

Knowing this little fact comes in handy sometimes, because you can quickly confirm you're remote (or whatever) is actually transmitting.

Re: Digital camera elements (1)

tleaf100 (2020038) | about 7 months ago | (#45941635)

problem is,it does'nt tell you what the remote is sending,such as a line of code that scrambled the operation of the remote for only a couple of tv's etc from the thousands it worked ok for. took weeks for that firm to find and fix for my remote. they suggested i take the lens element out of a cheapo webcam and to look for the ir filter film,slip it out,lens back in,roberts your relative,you have quite a sensitive ir camera,depending on sensor type,quality etc for a very cheapprice,i did it to a few slightly better cameras recommended on astronomy sites for hooking

Re: Digital camera elements (1)

tleaf100 (2020038) | about 7 months ago | (#45941757)

bloody /Â to continue. on astronomy sites as good for connecting to telescpes for astronomical work but they also make very good outdoors hd security cameras for a cheap price if you house them properly and spare kit to hook them to (old dell precision workstation,early pentium 4's

Re: Digital camera elements (1)

Muad'Dave (255648) | about 7 months ago | (#45951491)

... roberts your relative ...

I'm probably one of the few Americans that got that - "Bob's Your Uncle!"

Robert's one of your parent's male sibling.

Re:Digital camera elements (1)

amorsen (7485) | about 7 months ago | (#45943537)

Infrared is quite a lot of spectrum though. Remotes use the part of the IR spectrum which can be easily detected and generated by silicon-based electronics. Unsurprisingly, silicon-based image sensors can also detect IR remotes.

Re:Digital camera elements (1)

Obfuscant (592200) | about 7 months ago | (#45942057)

Actually, many digital cameras will pick up infra-red.

A much more interesting use of the IR capability of a camera is to test the output of your green laser pointers. Green is produced by using a high power IR laser and frequency doubling it into green. The process is not 100% efficient, and if the company saves money by leaving out an IR filter you get a laser pointer that is dangerous in the IR yet invisibly so (except for the green part).

Here [technologyreview.com] is a summary; This [arstechnica.com] has a more complete diagram of the testing setup.

Passive IR goggles (1)

Immerman (2627577) | about 7 months ago | (#45940975)

As neat science toys go - I came across plans a while back for passive IR goggles - you replace the lenses in a pair of welding goggles with a combination of theatre gels that block all visible light while allowing IR through. That allows your eyes limited natural ability to perceive IR to operate without being completely drowned out by the visible-spectrum light. It only really works on bright sunny days where the IR light source is sufficient, and you can't see thermal IR at all, but birds look freaking incredible.

Re:Passive IR goggles (0)

Anonymous Coward | about 7 months ago | (#45941165)

Ever show that to one of those xtians? They don't believe that non-visible light exists. I'd love to hear how they explain what they see.

From reading the other comments, I see several CONservatives are trying to turn this into a political discussion, as they always do. The way they do that gets tiresome.

Re:Passive IR goggles (0)

Anonymous Coward | about 7 months ago | (#45941235)

Some of the xtianists believe UV exists, but IR is a lie like global warming or the moon landing. Those people are crazy. And, you're right they try to make everything political. It's horrific how they have destroyed the M$M media in this country by forcing them to constantly talk about politics and religion. They're the type of people that ruin parties by droning on about politics and religion. They're so tiresome with their rants and intolerance. I just wish those idiots weren't allowed to disrupt this site and others. They just don't get that tolerance of intolerance is intolerance. They complain about intolerance when we try to stop their intolerance. Guess what? It is tolerance that makes us not tolerate your intolerance. Stupid xtians. Why can't they get that?

Re:Passive IR goggles (0)

Anonymous Coward | about 7 months ago | (#45941383)

They don't believe that non-visible light exists.

That's unfair. Some of them have electricity and watch Faux Knews. They understand that the signal is being sent through the air. To say that they don't believe it exists is to say that they don't believe Faux Knews exists. We know they would deny that. Sensible people know that it shouldn't exist, but it does.

Again, you're being unfair to the stupid religious people.

Re:Passive IR goggles (0)

Anonymous Coward | about 7 months ago | (#45962591)

Moron.

Re:Passive IR goggles (0)

Anonymous Coward | about 7 months ago | (#45941927)

I suppose it comes down to what you define as IR. If you go with a functional definition of it being light range with wavelengths just beyond what humans can see, no passive device is going to help. If you go with the more modern, arbitrary cutoff of 700 nm, you can see 700-740 nm stuff pretty easily without much effort, even without dark adjusted eyes (I've noticed from experience when trying to align a spectrometer), and stuff beyond that it comes down to how good your eyes are, the conditions, etc., and you can find situations where you can see the IR without such goggles. But beyond 800 nm would probably be superhuman...

Re:Passive IR goggles (1)

Muad'Dave (255648) | about 7 months ago | (#45951569)

... no passive device is going to help ...

What about a frequency-doubling crystal [wikipedia.org] ? Could they be used to 'see' IR light, or do they require such high input light levels and/or monochromatic light to work?

Sony Nightshot (0)

Anonymous Coward | about 7 months ago | (#45940999)

You're right about the clothing bit. Sony forgot about this with their Nightshot equipped cameras and it made the headlines back in the 90's.

Re:Digital camera elements (1)

DerekLyons (302214) | about 7 months ago | (#45941047)

I've always wondered why we can't do simple infrared or ultraviolet examinations of things with our smart phones.

You could - if the phone were equipped for it. But there's very little call for such capability and no very much use for it if you aren't a specialist, so there's pretty much no motivation for the phone manufacturers to spend the money on more expensive cameras that almost nobody want to buy.
 

I have a sneaky suspicion it's because not all clothing is opaque in those spectra

You're as ignorant of science as you are of economics.

Re:Digital camera elements (1)

similar_name (1164087) | about 7 months ago | (#45942287)

You're as ignorant of science as you are of economics.

He's not totally off-base on the science [wired.com] .

Re: Digital camera elements (1)

tleaf100 (2020038) | about 7 months ago | (#45941377)

most cameras these days have/need an infrared filter to actualy keep it off the sensor array.so that tends to stop it being used for usful things. i thought we were meant to be using theta waves or somesuch as short range radar by now ?

Re:Digital camera elements (1)

ceoyoyo (59147) | about 7 months ago | (#45941889)

You can. You just have to remove the filter in front of the sensor. Astrophotographers have been doing that to their SLRs for years, so much so that Canon released a special (and expensive) version of one of their digital SLRs without the filter.

Regular cameras have the filter so that the pictures don't look weird. But if you remove it and put on your own IR filter you can do IR imaging. It's difficult though, because the sensitivity of the sensor to IR and the properties of the filter mean you're essentially taking very low light pictures.

Sony famously released a camcorder with a low-light IR mode. It could see through clothes.

Re:Digital camera elements (1)

mikael (484) | about 7 months ago | (#45942233)

You can. You just need the right filters - Hoya H72 comes to mind. You can easily buy a set from the professional camera store of your choice, then you can do your own infra-red photography. It's better buying a set because some filters totally obscure all the infra-red light. The other material of choice is a black plastic refuse bag. That blocks visible light, but the chances are, it is transparent to infra-red light.

But if you want to do something now, just activate your smartphone camera, find a remote control and check to see if it can detect the flashing infra-red LED when a button is pressed.

Re:Digital camera elements (1)

jafac (1449) | about 7 months ago | (#45942549)

many digital camera sensors are actually pretty sensitive to IR; however, most manufacturers put IR filters on the sensors, because what we want is visible light, when we're taking a photo. I've seen mods on hackaday where someone who wants to do IR photography removes the IR filter on the sensor. (which is doable, when the filter is a separate glass or plastic plate, and not bonded to the surface of the sensor).

Finally found their niche (1)

redmid17 (1217076) | about 7 months ago | (#45940785)

FTA: Or more commonly, for travellers who want to measure their radiation dose as they fly, since those taking frequent polar air routes between north America and Europe receive a significantly higher dose than others.

Man am I glad smartphones are finally getting out and about in public. This is the year of the smartphone! Hopefully we'll be able to use them to sense the ambient air pressure while in our submersibles soon.

Re:Finally found their niche (0)

Anonymous Coward | about 7 months ago | (#45942431)

We've been able to quantify air pressure with a smart phone for a while now. One of the more popular android phones, the galaxy s3 [samsung.com] has a barometer in it.

Re:Finally found their niche (1)

bob_super (3391281) | about 7 months ago | (#45942651)

I hope it's not connected to the web, I don't the wrong people to be able to read the pressure in my pants.

Internet archive (1)

gmuslera (3436) | about 7 months ago | (#45940803)

It would work with already taken photos and stored all around internet? along with gps coordinates and date of the photo could give a good use a big (photographic) data.

Re:Internet archive (0)

Anonymous Coward | about 7 months ago | (#45941119)

It would work with already taken photos and stored all around internet? along with gps coordinates and date of the photo could give a good use a big (photographic) data.

If you can find lots of pictures with the lens covered, then yes. These gamma ray streaks are going to be nearly impossible to find in a real image. How can you tell if a streak is part of the scene or a gamma streak? On top of that, the sensor needs to be calibrated first. That requires a number of "black" images to sort out which pixels are noisy, etc. So, yes, if someone uploads many many images with the lens covered, but I don't think you'll find many people doing that, but I imagine a Facebook post saying, "Look! I forgot to take the lens cap off again!" People will post anything.

app? (1)

CAIMLAS (41445) | about 7 months ago | (#45941043)

So, if this research has been done and it's been shown to be tenable, where are the apps so we can do so ourselves?

Presumably they did this on various Android phones and maybe an iPhone or two? I don't see anything in Play.

Re:app? (1)

BringsApples (3418089) | about 7 months ago | (#45941133)

From TFA:

...an interesting question is whether Cogliati and co will make their app available to the public. They publish certain parts of the code in their paper but make no mention of their future plans for the app they call CellRad.

Re:app? (1)

dvase (1134189) | about 7 months ago | (#45941143)

From the article, they haven't released the app yet, and there are currently no plans to do so.

Travelers? why? (1)

Gothmolly (148874) | about 7 months ago | (#45941269)

If you have to fly a lot, you're going to fly a lot, whether your phone tells you its bad or not. Neat application of the technology, but not terribly useful to the average joe.

Re:Travelers? why? (1)

bob_super (3391281) | about 7 months ago | (#45942671)

I'm sure a lawyer somewhere is salivating while going over airline disclosures... The average Joe may make him a lot of dough.

Re:Travelers? why? (1)

geekoid (135745) | about 7 months ago | (#45944763)

It could be useful one the data is correlated. Having thousands of sensors constantly detect radiation and different altitude could reveal some interesting things.

Re:Travelers? why? (1)

Gothmolly (148874) | about 7 months ago | (#45957053)

The data would exist on 1000s of private sensors, so it would be useless in the aggregate. Or are you advocating seizure of the devices and data in the name of sum public good?

App (Android and iOS) (2)

bammmmm (3498549) | about 7 months ago | (#45941313)

here is an app from 2011 doing exactly that: video (there are a few): http://www.youtube.com/watch?v=GAWQ-YT8BvE [youtube.com] android: https://play.google.com/store/apps/details?id=com.rdklein.radioactivity&hl=en [google.com] iOS: https://itunes.apple.com/us/app/radioactivitycounter/id464004677?mt=8 [apple.com]

Re:App (Android and iOS) (1)

bammmmm (3498549) | about 7 months ago | (#45941435)

their testing rig (they say the need to calibrate for each sensor): http://www.youtube.com/watch?v=ebpscjKRCqo&list=TLLo4ClqO-MR1qNLMR2pmVUlNWJ9vHPa3f [youtube.com] here is how it looks in a camera: http://www.youtube.com/watch?v=MsG6JsMAJ_Q&list=TLfAlmzrsJfvVS3vQYz9U_rXt_tnYi_Igk&feature=player_detailpage [youtube.com]

A few apps exist already (4, Informative)

mspohr (589790) | about 7 months ago | (#45941497)

TFA states that the "may" release the app but there are already a few gamma radiation detectors on the Play Store for Android such as these:
https://play.google.com/store/apps/details?id=eu.camdetector.radiationalarm&hl=en [google.com]
https://play.google.com/store/apps/details?id=com.rdklein.radioactivity&hl=en [google.com]
Basically you cover the lens with black tape to block light but of course gamma radiation can get through. The apps need to be calibrated to your individual phone since random noise in the sensor can give false readings. The apps provide a method to do that.
As the article states... the best radiation detector is the one you have with you.

Re:A few apps exist already (1)

jfengel (409917) | about 7 months ago | (#45941871)

Sorry to be dense (ahem), but why "of course" are they transparent to gamma radiation? Gamma particles have high frequencies, and so more energy, but doesn't the short wavelength make them prone to being absorbed (all other things being equal)?

IINAP, so I could well be wrong about that, but that was my understanding.

Re:A few apps exist already (3, Informative)

mspohr (589790) | about 7 months ago | (#45942123)

Wikipedia has some good references here:
"Shielding from gamma rays requires large amounts of mass, in contrast to alpha particles which can be blocked by paper or skin, and beta particles which can be shielded by foil. Gamma rays are better absorbed by materials with high atomic numbers and high density, although neither effect is important compared to the total mass per area in the path of the gamma ray.
The higher the energy of the gamma rays, the thicker the shielding made from the same shielding material is required. Materials for shielding gamma rays are typically measured by the thickness required to reduce the intensity of the gamma rays by one half (the half value layer or HVL). For example gamma rays that require 1 cm (0.4) of lead to reduce their intensity by 50% will also have their intensity reduced in half by 4.1 cm of granite rock, 6 cm (2½) of concrete, or 9 cm (3½) of packed soil. "
So, gamma rays can pass through black tape, plastic and glass lenses without much difficulty.

Re:A few apps exist already (1)

jfengel (409917) | about 7 months ago | (#45942323)

Interesting. Thanks.

They also pass through airplane skins, presumably. But I wonder how many of the particles that pass through airplanes and tape will also be intercepted by sensors?

I suppose the only answer needed is "enough to calibrate against."

Re:A few apps exist already (1)

MarkRose (820682) | about 7 months ago | (#45947603)

Easily through airplane skins, which are usually constructed of light materials. Cosmic rays are all over the x-ray and gamma spectra, and while you will absorb some, most of the very high energy gamma cosmic rays will pass right through you. However, the increased radiation is easily detectable [youtube.com] .

Re:A few apps exist already (1)

Bearhouse (1034238) | about 7 months ago | (#45943455)

Depends on both frequency and energy level.. Of the two, energy level is the one to watch for...very high energies can only be attenuated by significant amounts of solid matter...like a yard of lead or concrete or water (surprisingly, lead is only about 30% max better at shielding than concrete...and a damn sight more expensive and harder to work than concrete.
Water, of course, helps with neutron radiation too, but I digress...
But if you're close enough to that kind of energy source your smartphone is the last thing you'll be needing - a good pair of running shoes would be more useful.

Back on topic, there's plenty of "interesting" gamma sources that will happily go through a piece of tape, and I suppose the paranoid could you this to check on their does rates while getting an X-ray

Re:A few apps exist already (1)

MarkRose (820682) | about 7 months ago | (#45947535)

I've used Radioactivity Counter [google.com] and it works quite well. With a Galaxy Nexus phone, it's about as sensitive to gamma as my GammaScout [gamma-scout.com] . Watch review [youtube.com] , or see it in action on a Chernobyl fuel fragment [youtu.be] . But I wouldn't make a habit of exposing a CCD camera to ionizing radiation, because it will damage it [youtube.com] .

Seems like a small detector assist is in order (1)

drdread66 (1063396) | about 7 months ago | (#45942729)

There are lots of ways of detecting gamma rays, but one really common way is through scintillation and/or fluorescence. Most common scintillators are small blocks of plastic. I'm thinking you could increase the sensitivity of the smartphone gamma system by simply taping a small piece of plexiglass to the outside of the camera lens, using plain old black electrical tape. Then the plexiglass would convert some of the gamma energy to visible light and the camera sensor would do the rest.

Total cost? Probably around $0.05 total.

Not for airline altitudes (2)

celticryan (887773) | about 7 months ago | (#45943071)

The majority of the dose at airline altitudes is from neutrons (55%), with only a small component from photons (gammas are photons) - 5%. This is, of course, on average. I do not think anywhere in the preprint they claim to be able to measure anything but photons. Therefore, a cell phone will not do a great job of monitoring your radiation dose at airline altitudes.

However, there is a tool being developed by NASA which does a real-time calculation of your radiation dose along an airline trajectory. Check out NAIRAS [spacenvironment.net]

References:
Cosmic Radiation @ skybrary [skybrary.aero]
NAIRAS aircraft radiation model development, dose climatology, and initial validation [doi.org]

Or use the motion sensors... (0)

Anonymous Coward | about 7 months ago | (#45946679)

When someone starts twitching the phone sends out an alert to all within range.

FTA: "There’s an old story about an old photojournalist who, when asked his opinion about the best camera, said the “one you have on you”. The same might also be said for radiation detectors."

How about as a radon detector? (0)

Anonymous Coward | about 7 months ago | (#45949979)

This might be a fair radon detector, maybe? Time will surely tell, methinx.

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