Can Spy Satellites read your Car Number Plate?

by Shahid on October 15, 2009

Since time immemorial(not really), people have been fascinated by spy satellites. Everybody wonders what they do and what sort of new information do governments have on each other. One of the most reliable sources of intelligence has always been Imagery Intelligence, from Aerial Intelligence to Imagery gathered using Satellites. From the days of Hot Air Balloons taking pictures, to the day of the U-2 and Sr-71 to the days of KH-11 and today’s era of high resolution commercial satellites, spy imaging has been a great asset for all governments.

A nearly universal myth tells the story of US and Russian Spy Satellites being able to read car number plates and the headlines of newspapers being held on a sidewalk clearly, but is that true? Here is the truth.

Rayleigh’s Criterion gives us the highest possible resolution for an optical device with a circular aperture. It is expressed as follows :

As explained clearly by me on Wikipedia, the Hubble Space Telescope has a Diameter of 2.4m. Hubble being one of the biggest bad-ass satellites ever launched should be able to see my car plate if it can see a galaxy a gazillion miles away. Mathematically, the highest possible resolution for Hubble comes out to be  around 16cm which is around 6.3 inches or half a foot. Now that is good enough to spot a car and a building in detail but not good enough to read a newspaper headline.

Modern day spy satellites have highest resolutions around 10cm and even that is not enough to read a newspaper headline. The Federation of American Scientists explain:

Resolution of 0.1cm

Resolution of 0.1cm - not possible in today's satellite technology

Resolution of 1cm

Resolution of 1cm

Resolution of 3cm

Resolution of 3cm

Resolution of 10cm - That of today's Spy Satellites

Resolution of 10cm - That of today's Spy Satellites

As clearly demonstrated above, a spy satellite can neither read your car plate or the newspaper headlines. Rest assured, the stories of Mao and Stalin being delivered chilling images of the US’s superior spy imaging capabilities will continue to be spread for generations.

Refer to FAS’s IMINT 101 for a quick lesson in Satellite Resolution and remember to take a look at famous galleries.

  1. Cuban Missile Crisis
  2. World War II Gallery
  3. Bosnian Genocide
  4. Al – Shifa Pharmaceutical Factory, Sudan
  5. Images taken from SR-71

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  • I believe it is possible to read a number plate from a spy satellite. Last week there was a news report that the British army took delivery of a new super zoom camera for use in Afghanistan.
  • Keep in mind that infrared imagery can be used as well so it would be a good idea to verify the infrared profile of an obscured object with a camera sensitive to infrared and use that information to make any necessary adjustments. Sheets of aluminized mylar could be used to obscure infrared profiles.
  • For a license plate you could use a filter similar to the privacy screens available for computer screens, placed so that it is viewable normally from street level, but it can not be read from above. Mindful placement of awnings, umbrellas, camo screen, etc.
  • For a license plate you could use a filter similar to the privacy screens available for computer screens, placed so that it is viewable normally from street level, but it can not be read from above. Mindful placement of awnings, umbrellas, camo screen, etc. could be used to obscure stationary objects.
  • I believe it is possible to read a number plate from a spy satellite. Last week there was a news report that the British army took delivery of a new super zoom camera for use in Afghanistan.
  • Greatful101
    You think you know it all? think again :) electronic cigarette
  • Chodpaba
    Link spam.
  • Inquirer
    Assuming from the conversation below that 'they' can read licence plates and newspaper headlines, how could one best protect one's reading matter/car identity from snoop sats/drones etc? I take it that most ordinary materials won't be much use. Would lead-based ones or similar? I'm writing a thriller so would like to get this sort of thing correct.
  • chodpaba
    One critical tool would be to disrupt the line-of-sight. Satellite viewing angles are anywhere from 90 down to 60 degrees of inclination, so consider a cone extending from the point(s) you want to obscure with sides extending 360 degrees around and inclined 60 degrees to be the area you want to obscure. For a license plate you could use a filter similar to the privacy screens available for computer screens, placed so that it is viewable normally from street level, but it can not be read from above. Mindful placement of awnings, umbrellas, camo screen, etc. could be used to obscure stationary objects. Keep in mind that infrared imagery can be used as well so it would be a good idea to verify the infrared profile of an obscured object with a camera sensitive to infrared and use that information to make any necessary adjustments. Sheets of aluminized mylar could be used to obscure infrared profiles.
  • This is really scary stuff right here.

    Your girl Mary :)
  • jmb
    Well it depends on the focal length of the lens used to capture the image in the first place. Take this example. I take a photograph of a Animal a few hundred meters away with a 200mm lens. But I need to crop the image to get close enough to see the animal "close up" or I take the same animal using a 800mm or longer lens and what do think happens. Yep. I no longer need to crop the image to get in close. Effectively gaining resolution. I terms of whats actually possible I would hazard a guess that a super telephoto lens of some 20000mm (yes thats 20 thousand ) or more is quite achievable you add a high pixel sensor to the mix lets say a 500 million pixel (150 million pixel sensors are already available to the public at "affordable" prices. But you can bet the US government will not settle fore some sensor that joe public can buy all be it a £25k+
    I believe it is possible to read a number plate from a spy satellite. Oh yea one more thing. Last week there was a news report that the British army took delivery of a new super zoom camera for use in Afghanistan. It has the resolution to seen and read London's BIG BEN at over 50km away. So if thats the technology we know of then reading number plates from space is very much a reality. Its not that far up into space when you think about it. A spy satellite sitting 75km in orbit with a camera 4-5 as powerful zoom as the one the army use and it will read the number plates of a car.
  • nunya123
    The assumption here is that the US spy satellites use solely optical technology

    Hint: they don't, look at radar resolution technologies
  • JMB
    adar can only see 3D images ie: cars, people, buildings etc. You get the idea. Well a numberplate although mounted on a 3D object is itself 2D ie: letters and numbers. I am a photographer by profession and know of the amazing resolutions available to me ad to this the amazing advancements in lens technology. They are adding nano crystals to lenses this corrects any distortion in the colour spectrum resulting in a far sharper image. The world of optics and didital imaging sensors has moves on so much in the last 10 years its amazing.
  • This post deals with technology that has been declared. Otherwise who knows.
  • but what's the state of current satellite technology for example in the USA? We don't know that do we?
  • littlepitcher
    Satellites don't need to. New spycams sold to cities and mounted on poles in high-crime locations can transmit tag data directly to a monitoring cop's computer.
    My SWAG is that next tech "advance" will be some sort of bar code or microchip which will be trackable by GPS.
    Bozo cops spend little time actually searching for stolen cars, and far more time harassing political protesters, in my extensive experience (one car stolen, a personal war with a KKK tag office employee).
  • hubabubba
    You have no clue and I have no comment for another...82 yrs....lol
  • What?
  • I don't know why, but I don't believe this is true.
  • Dan Beaulieu
    Well since a satellite shoots from overhead, and your plate is not face up strapped to the top of your car, I'm going to have to say it's not really a resolution issue. Maybe the top-end satellites can read large print, but only if the paper is pointed up! ...unless I'm missing something.

    Until I can drive my van up the side up a building, the angles won't work out.
  • chodpaba
    If you can read the license plate standing three feet behind a car it can be seen by a satellite. Even the ancient Corona satellite could capture images from inclinations as little as 60 degrees.
  • mstuartm
    This post relies on some very dubious assumptions, IMO.

    I prefer to rely on another assumption: Advanced U.S. military technology, including imaging technology, runs 2-3 generations ahead of what the best non-classified, private-sector technology can deliver.

    It is safe to assume, for example, that non-classified U.S. aircraft technology is far behind the current (classified) state of the art. I fail to see why that shouldn't apply to IMINT technology, as well.

    Also consider that cost -- by any reasonable definition of the word -- simply doesn't apply to U.S. military and intelligence R&D efforts. These organizations are willing to spend billions on a series proof-of-concept projects that ultimately fail, simply to identify and exploit the one that bears fruit.
  • Name
    You did not talk about inference. For example, from space you can identify a pack of cigarettes or similar not by actually seeing it directly, but by comparing its pattern (usually via infrared or similar) to known patterns. The inks in cigarette packs are generally different enough that you can tell them apart.

    So while you may not be able to read a news paper from space, you can infer which paper someone is reading based on some fuzzy matching against known papers. This also works for other items where there is a profile on file (which for newspapers would have to be done at least daily if not multiple times a day). In this way you can make educated guesses about items that are below the resolution of a given satellite.

    The items of course have to be big enough to register on the camera system however.
  • This is the technology that we know of. Just look at the electronic cigarette, who wouldve thought it existed but the technology has been around for awhile.
  • Name
    i highly doubt that we know what these satalites are capable of this is the government we are talking about we cant compare civilian tech with government tech for example they had the internet before we knew of an internet they were at 22 megapixels when we discovered that its possible to have digital cameras its not a conspiercy its just the government they dont want possible threats using similar tech so im sure they have at least one satalite that can read your tag the hubble is old as hell and it does amazing things
  • Dude
    0_O Except that hubble is almost 2x as far away as a spy sat would be. Supposedly newspapers are easier to read when you move them 250km closer.
  • jasand
    so those movies are really just fiction where they zoom then press the magical enhance?? how dare they fool us like that?
  • arkid77
    Making a comparison to Hubble is misleading. Often hubble is used in comparrisons, as in "well it should clearly be able to see the moon landing traces so why hasnt Nasa ever taken photos of that! (please lets resists moon landing haox talk!).

    Making a similar comparison, suggesting that pointing hubble at earth will work is equally missleading. Hubble was never designed to focus on small objects at close range and as a result of its very specific optics is incapable of doing so. It was naturally intended to study super massive objects very far away, light years across in scale in areas of deep space.

    Its like trying to use a 200mm SLR camera lens with someone half a meter in front of you and wondering why the person wont go into focus. Its just not possible.

    For reference; Hubble, according to Nasa can in short range if say poitned at the moon only focus in on items at around 60 meters or larger in form. This is something they have done and theres some photos on the nasa site of this.
  • pt
    If you have ever had a manually controlled camera, you should know that anything farther than about 10 m is at infinity for it. Scaling a camera 100 times gives something much bigger than Hubble, so already 1 km is definitely at infinity and switching between even farther objects needs absolutely no refocussing. The angular resolution of the Moon and a galaxy would be really exactly the same and limitted only by diffraction on the aperture (which is estimated by the Rayleigh's criterion).
  • It might have been misleading but I used it only to refer to the commonly accepeted maximum resolution of 10cm for modern day imagins satellites
  • fuckface
    i can't read a car license plate if i am floating above it as i would see it edge on (duh). why would i want to read a newspaper headline exactly? ;)
  • Steven Hipkiss
    Wow, your explanation is brain dead. Rayleigh’s Criterion is a generalisation for HUMAN OBSERVERS - it is not fact, it is an approximation based on experimentation. You should look at Dawes' limit for a proper answer.
  • I will surely check that
  • dihhuit
    The real assumption here is that the government doesn't have satellites with sufficiently large diameter optics to give them the resolving power to read a license plate. How can we make this assumption? The technology exists--just because they don't tell us it's up there doesn't mean it isn't. At that point, however, the limiting resolution would be dominated by atmospheric turbulence. But, they could equip it with adaptive optics...what they would use as a reference image though, I have no idea. Can't use lasers like astronomers do, since the layer of atmosphere off of which they reflect is between you and the rest of the atmosphere (not to mention, shining a bright laser at your spy target is somewhat silly). My point-the technology to read license plates from space exists, it's simply a matter of whether or not some bureaucrat thought that it was sufficiently cost effective to do such a thing. Why would they tell us if they did?
  • Finally someone with some actual thought put into this "idea" about technology.

    Though I don't agree that weather limits us anymore, think about what we've been doing at Saturn with casini etc

    We have sent sattelites to another planet hundreds upon hundreds of thousands of miles away, and this sattelite is capable of "looking" through clouds, in other words it gathers data through other means, it does not require direct light energy to generate an accurate image of the landscape below what we know as the thickest and violent atmosphere in our solar system on what is the biggest planet in our solar system.

    So ya, if Nasa has this tech and tells us about it, I have no doubt they can see even to the width of a hair and do it through clouds/storms whatever atmosphere you want.
  • Name
    //Hubble being one of the biggest bad-ass satellites ever launched
    You think so because thats what we're told. Maybe there are even more bad ass satellited up there which we're not aware of..
  • Speculation is the game of idiots.
  • haha you just keep going don't you?

    Speculation, well, lets see, you've done nothing more than speculate with this entire blog/article or w/e you call it. You've "assumed" and you've "speculated" that there is no technology out there which we do not currently know about, you've "speculated" that we are merely limited to satellites capable of a pathetic 10cm which we've had for 30 years already.

    So why are you playing this game of speculation when its the game of idiots? O wait, I know! You're an _ _ _ _ _ !!!! I'm sure you can fill in the blanks, its should be easy, even 'idiots' can do hang man puzzles right? Even a caveman can do it!

    You are either very clever or very lucky to have named the title of these empty and lifeless 2 paragraphs with a question..... "Can Spy Satellites read your Car Number Plate?" You have the gift of the retarded media goliath in you my friend, throwing out a bait question is the easiest way to grab a readers attention while still remaining protected from "fault/blame" if your information is totally misleading or hand picked to sway your point
  • You have too much time on your hands to reply to posts you regard as retarded and stupid
  • Dean
    Unless the licence plate is on the roof of your car, I don't get how a satellite looking down at the earth could see it?
  • chodpaba
    The inclination on the KH-4B Corona satellite was as little as 60 degrees.
  • DoktorF
    Except that they were reading newspaper headlines from spy planes in the late 70's.

    I believe they have optical integration and deconvolution techniques that can resolve much more now from satellites.
  • chodpaba
    The analysis you present describes the theoretical limits for a device to produce a single image. However, by using multiple exposures of the same object, images can be combined using probabilistic deconvolution algorithms to far surpass this theoretical limit. Deconvolution techniques have been used to great success with Hubble images, and there is every reason to expect that images from spy satellites could be similarly advantaged. 10 cm resolution is still a remarkable achievement, but it is absurd to think that intelligence collecting agencies would reveal the full technical capabilities of their systems.
  • Deconvolution is as good as the number of images available. Although your point is valid and holds ground, I seriously doubt that any satellite is able to read a car license plate.

    The image forensics in CSI and all other shows is pure fiction. Deconvolution, pixel averaging and removing motion blur cannot read the numbers from an image that showed the whole thing as two or three pixels. However, a burst of photographs might be able to render something sensible
  • chodpaba
    Pixel averaging is an example of superimposition, which is a much less sophisticated method than deconvolution. And you are mistaken to conclude that even a single pixel image could not be resolved given deconvolution algorithms. A simple example of deconvolution using single pixel images is that of the old prototypes of television cameras that used a mechanical mask to expose a single photo sensor (a single pixel) to the varying light levels of different parts of the object. The string of single pixel images can then go through the process of deconvolution to reconstruct an image of the object because the method used to deconstruct the image is known. Modern techniques such as blind deconvolution use statistical methods to reconstruct images even when it is not known exactly how the image is scrambled, and using recursive algorithms to further refine the image through successive approximation is possible with enough data and computing power. So, using single pixel images is an extreme example, but if you have enough low resolution images that you can get corellative data from you can reconstruct the recognisable image of an object. That being said, passive techniques using ambient light from the object can be enhanced using data from laser telemetry to provide more information to reconstruct the image of an object. This technique is used in astronomy to cancel out perturbations cause by the atmosphere and render sharper images from ground-based telescopes. There is every reason to believe that the same methods can be used for looking in as for looking out.
  • ThinkMan
    Rubbish...youve made no allowance for image processing/enhancement. Mulitple photos of the same spot digitally enhanced and correlated Im sure could provide a number plate or even a newspaper headline.
  • mnocket
    I'm no expert, but why are you using the equation for angular resolution? Shouldn't you use the equation for spatial resolution (delta l)?

    http://en.wikipedia.org/wiki/Angular_resolution
  • Name
    CCTV certainly can. Yay.
  • mauriceh
    Really? Go to Google Earth
    Zoom in on Las Vegas, on the strip.
    That looks a bit better than what you describe.
  • moi
    High resolution pictures in Google Earth are obtained from aerial photography, not from satellites
  • I did not say they were from satellites. Even aerial photography can't render the mythical "newspaper headline"
  • Post an image of the highest resolution image available on Google Earth. You can identify objects but not read plates and newspaper headlines
  • Guest
    I believe that myth comes from the fact that spy planes had enough resolution to read newspaper headlines and license plates, not satellites.
  • Name
    Obviously they havnt been the spy museum in washington DC
  • I would love to be there. Although I haven't been able to find much on the stuff on display
  • jjesusfreak01
    You assume Rayleigh's Criterion still stands. Interpolation from a series of images, or even video, can increase the resolution considerably (probably at least 3x), and you cannot assume a circular aperture.
  • Obviously we cannot assume circular apreture for everything but the KH series of satellites used circular aperture and they were the most used remote sensing and imaging satellites.

    As for your idea of interpolation, that is true as well but still cannot enable any satellite to read the mythical "newspaper headline".
  • vroomvroom
    10cm my ass. Modern Sats can read the "no.2" on a number two pencil.
  • That's your assumption not the reality. IMINT, HUMINT nad MASINT combined give the best results. If IMINT was so powerful than there would hardly be any need for ground intelligence
  • Guest
    reply to chodpaba's comment, u seem stumped by his knowledge :)
  • exintelgeek
    You're assuming IMINT is limited only to satellites and planes which is incorrect. There are a ton of different ways IMINT data is collected. Satellites are one of the poorest due to the nature of the resolution and the tasking of a satellite. It's not easy to time a satellite to cross over a specific point at a certain time and guarantee good (cloudless) weather to achieve the level of detail such as reading a newspaper headline. Whether that's possible or not, I don't know. However it can collect other data such as heat signatures and the like to continue gathering information even if it's not taking what we're used to (standard photo). Also, what I do know in my limited experience with IMINT is that it's used to gather large scale intelligence. Then planes (more often drones) actually collect the more detailed data. Finally the HUMINT/IMINT hybrid comes into play for very detailed intelligence.

    So, your title of your article is relatively misleading. "Can Spy Satellites read your Car Number Plate?" I would not be surprised to learn that there exists the technology to do so. However, they don't. The need to develop that technology vs. investing in other intelligence gathering technology just doesn't warrant the need. Why spend the money on satellites when you can get a better return on your investment with drones. If something is so important that we need to read what paper is in a person's hands, it would be much more efficient to gather that intelligence another way. Not through satellites. But if we wanted to, we probably could....
  • Technically your hypocritical by this statement; in your own words you are assuming that there is in fact no imaging technology capable of reading the "no.2" text on a number two pencil. Your 'assuming' that in what we define as "reality" there is no chance that doing such a task is possible, while " vroomvroom " is assuming that there is a chance that doing such a task is possible. Who says your assumption is more valid than his assumption in this "reality".

    And as other people have stated previously, do you really think they would ever divulge any information on "current" technology that is in use by our CIA/FBI or Military? If they want to keep anything secret they can do so for decades upon decades depending upon the tech's amount of use and quality of use; its a satellite, aka a small object that is in the orbit of our planets gravitational pull, in a location which easily the least accessible place for any human being to reach thus easy to keep secret(especially with the use of control groups, meaning there are many different parts of the final product/project being put together by many different contractors who have no clue what the final product is and can't ask questions or talk about their work that would result in lawsuits/prison sentencing, only a few people know thus allowing easier control of highly sensitive information)

    Considering the amount of organization and control that goes into such projects, I have no doubt there is technology out there which defies what you would term "reality".

    Look up information about Tesla and how the world was robbed of whats known as a "free energy device" around 100 years ago, might open your mind as to whats possible and whats been done over 50 years ago that makes modern public technology look like childs play
    :-)
  • I would have agreed with most of what you said had you not mentioned that you're another "free energy supression" conpiracy theorist. Dorks sitting in front of computer screens have nothing more to do than speculate and edit wikipedia articles about "free energy suppression" . As much as I respect Nikola Tesla, I'm pretty sure he would have been stunned by your idiotic conspiracy theories as well
  • Name
    Don't also forget the most surveillance satellites only pass by any given point on the earth 2-3 times a day depending on their orbit.
  • Guest
    However, the speed cameras that are recording live video 24x7 will have no problem at all reading my license plate :)
  • Brad Pitt
    Liar liar pants on fire!
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