License-Plate Scanning by Helicopter


The fictional police spy helicopter from the movie Blue Thunder is taking a big step toward becoming a reality. Police in the UK have successfully tested a 160 MPH helicopter that can read license plates from as much as 2,000 feet in the air. The Eurocopter EC135 is equipped with a camera capable of scanning 5 cars every second. Essex Police Inspector Paul Moor told the Daily Star newspaper: “This is all about denying criminals the use of the road. Using a number plate recognition camera from the air means crooks will have nowhere to hide.”

The use of Automated Plate Number Recognition (ANPR) is growing. ANPR devices photograph vehicles and then use optical character recognition to extract license plate numbers and match them with any selected databases. The devices use infrared sensors to avoid the need for a flash and to operate in all weather conditions.

This is an example of wholesale surveillance, and something I’ve written about before.

Of course, once the system is in place it will be used for privacy violations that we can’t even conceive of.

One of the companies that sells the camera scanning equipment touts it’s potential for marketing applications. “Once the number plate has been successfully ‘captured’ applications for it’s use are limited only by imagination and almost anything is possible,” Westminister International says on its website. UK police also envision a national database that holds time and location data on every vehicle scanned. “This data warehouse would also hold ANPR reads and hits as a further source of vehicle intelligence, providing great benefits to major crime and terrorism enquiries,” a Home Office proposal explains.

The only way to maintain security is not to field this sort of system in the first place.

Posted on April 15, 2005 at 12:10 PM27 Comments


Zwack April 15, 2005 10:41 AM

It’s worth remembering that the Police in the UK can use evidence obtained illegaly in your trial. In other words, if you were in the area of a crime (your number plate was scanned in the rough vicinity) then the police could break into your house (which is an illegal act) and see if they could find any evidence. If they found evidence of any crime then that evidence could be used against you in a trial.

Not that I’m suggesting that they do that very often, but it’s a scary possiblity.


Joe April 15, 2005 1:29 PM

Normally I’m the first to stand up and applaud for what Bruce writes in the articles and what many commenters add to the discussion, but I’m not sure I understand the issue in this case. (Though that’s not saying that I can’t still be convinced.)

We’re afraid of “privacy” violations, but there is nothing being monitored here that is not public already. They aren’t recording what you are doing in your own home, they are watching who is using a government-licensed car on government-supported public roadways for people who have committed criminal acts. This is ALREADY done regularly, the only news is that it is now possible to do it in a more automated fashion.

Since any individual, corporation, or law enforcement entity can currently follow your car in public areas, accidentally happen to see you, or keep watch for particular individuals, I don’t see how a person has a reasonable expectation of “privacy” while going about in public.

optoblog April 15, 2005 1:45 PM

I think Joe should read more fully some of BC’s writings.
How is license plate scanning going to find real criminals? Won’t they just take a cab or use someone else’s car who doesn’t have a record?

Tom April 15, 2005 2:05 PM


I think this kind of system is to be put in place to combat particular types of crime rather than all criminals; there is still a lot of car crime in the UK so this may just be another way of combatting that problem.

Davi Ottenheimer April 15, 2005 4:23 PM

The common evasion methods I’ve seen are to cover license plates with polarized, anti-IR, or reflective plastic or (most recently) simple plain pieces of paper. And, as long as we’re referencing film, there was the system that 007 had in one of the Cannonball Run movies — a plate with several sides that could be rotated like those billboards that change.

Even the most sophisticated evasion methods seem very low-tech and inexpensive compared to the heli-cams. It will be interesting to see if these really reduce present crime rates, or if they will be used to justify the creation of a whole new profile of “suspected” criminal activity.

John April 15, 2005 5:35 PM

Davi, your observation about the “rotating” license plate is quite valid. For that matter, a criminal could just switch plates manually with some random car in any parking lot and many owners wouldn’t notice for quie a while.

As far as the other methods, it’s already illegal in many (most?) areas to have an obscured plate from mud splashes, snow, etc. By that measure someone INTENTIONALLY obscuring their license from the authorities would certainly be illegal, I would think.

Without these systems in widespread use the police have been somewhat lax in enforcement, since they may have more efficient ways of spending their time. But if speeders started getting an extra fine on their tickets for having an obscured plate, I’d bet fewer people would be breaking those laws.

Quadro April 15, 2005 9:07 PM

Wow, I didn’t know about that UK rule about illegally obtained evidence. I’d rather have the courts throwing out evidence on a technicality than allowing anything, as the police would be encouraged to break the law to obtain evidence.

The information may be public, but this is all about making it easier for the police to obtain it. If it’s easier to obtain this information, it will be used too extensively, a very slippery slope situation. In addition, it’s much easier to notice when somebody is following you or recording your plate number manually than it is to spot the helicopter, because most people don’t think such a thing is actually possible. And, as optoblog pointed out, many criminals steal cars, although this system could combat that by searching for cars reported stolen. But if you’re going to do that, then you should make it less prone to abuse (e.g. link it to the police database of reported stolen cars, make it so that it can’t report anything except that it saw a car on the stolen database, and link it directly to the DMV database for stolen car plates so that the police can’t make their own list).

If these things become common, we’ll all have to get license plate obscurers (like those now available for toll fraud and possibly some legitimate uses). Some people might even decide to shoot the things down – remember that one man’s terrorist is another man’s freedom fighter.

brian April 16, 2005 12:41 AM

I read about a similar system to be used on tow trucks and police cars:

The tow truck drives around until the computer beeps, indicating a car with an outstanding parking ticket (or some other heinous crime), and they tow it.

Put one on a helicopter instead, and have the onboard computer automatically send GPS info (or addresses, if its that smart) to dispatch tow trucks. They could get everyone. They’d probably even pull in enough money to pay for a larger impound structure to hold them all.

It makes the police way more efficient at collecting cars, but it doesn’t catch criminals.

Jim Dermitt April 16, 2005 6:24 AM

Look out for more stolen license plates.
Maybe they will make you weld the thing on your car next, since screws are so easy to defeat. Look out for criminals with hammers and chisels next. Maybe this will force all the criminals to use taxis and buses more often. Put cameras in all the taxis and buses and hurry up. Maybe in the future, the police will just stop carrying guns and all carry cameras and stun guns. The criminals will all have guns and bullets. The police can stand there and take photos of the guys robbing a bank carrying M-16’s and Smith & Wessons 10mm autopistols. We can find the criminals with RFID technology and then stun gun them when they are not looking. I think I’ll stick with real guns and real bullets. Real police carry real stuff. This all sounds like more BS from the digital paperless, wireless security guru consultant crowd. Back to the basics guys. Gunpowder and paperwork, is a part of police work. If the officer has a stun gun and the perp has a .45 automatic, the officer could get dead in real time. Stun guns could be a big problem. Maybe they’ll build stun guns with built in cameras, for added security. Don’t give up your handgun just yet! They could borrow your license plate at night and return it before you wake up and bingo, you must of been there since your plate was spotted. Take your plate off at night and take it in the house. Maybe we should just get rid of auto license plates with all of this ID theft.

Anonymous April 16, 2005 8:14 AM

First off as I have said before there are too many guns in the hands of people that do not have sufficient training to use them properly (and yes this includes nearly all police officers who carry guns in the world as well as the criminals).

@other readers
Having got guns out of the way it’s back to my usuall comment when it comes to automatic number plate reading, that it’s all about raising revenue (see earlier postings by me on this). If you don’t beleive me then read the arguments below.

The UK has more survalence cammeras than just about any other place in the world and street crime continues to rise.

So we know sufficient to say that the cost of cammeras is not justiffied for crime prevention (ie it’s been proven not to work). Therefore we need more Police on the ground, however other UK government policies (reporting and statistics) have acted to keep them off of the streets.

Secondly the politicians need lots and lots of money for there voter buying scheams, at least one of which is to get more Police on the streets…

This is a significant problem especially as the UK population over the age of retirment is rising quite dramaticaly whilst the birth rate is falling. So predicted earnings from direct taxation is going to drop, whilst the need for money to pay for social needs is going to rise.

However UK Politicians cannot get more money by increasing direct taxes as the majorotiy of them subscribe to the theory that it’s a vote losser. The current government has put in place more indirect “stealth taxes” than just about any other in the history of mankind, and guess what, still not enough money.

There is a test of the theory about increasing direct taxes loses votes comming up in the UK, a UK party has anounced it is going to put up some taxes, however only for those earning over 200,000USD equivalent and this is less than 1% of the population so it may not be a very good test.

The UK also has a couple of other quite serious problems. The first is too many cars on the roads, causing significant congestion. The second is the UK’s commitments to green house gas emmision reduction. These are not unrelated to each other.

To combat the first problem we tried congestion charging in the Capital City (London), that shifted the vehicals out of the congestion zone but did not get them off the road. They just went around it making the congestion worse in other areas and increasing fuel consumption / polution as well. Yes there has been a reported increase of polution based disease in the areas surounding the zone.

The politicians see it as a partial win in that it proves charging gets vehicals out of the charging zone. There is now a proposel to make the zone even bigger but it is facing significant and vocal opposition. This is not just from drivers but businesses that have lost significant amounts of trade.

Although there are no hard and fast figures, there have been comments made to the effect that there has been an increase in the number of businesses in the zone closing and an increase in unemployment. If this is true it will mean a decrease in income for local government and a consiquential increase in cost to central Government which is not desirable.

With regard to grean house gases cars are seen as one of the worst offenders, therefore we need to get them off of the roads.

The worst offenders genneraly being touted as “company cars” (actually its vans, lorries and busses, but the various UK political parties attitudes to rail transportation is decidadly anti).

Sucsesive UK governments have tried various tricks to reduce the number of company cars via the tax system but it has not worked very well.

So put,

1, A political need for money
2, Excess cars on the roads
3, Green house gas emmision problems
4, technology that identifies all cars on a given road

Together with the realisation that localised survalence does not work (ie the problem moves to where there is no survalence). ALso from the GATSOS (fixed speed cammeras) that people adapt to fixed survalence if it is insufficiently dense.

You then start to come up with the idea that you need blanket road survalence, but we cannot afford blanket survalence.

So you come up with the next idea that if we put it on busy streatches of road we can raise money by charging (Tolls etc) we can then use this money to buy more cammeras, and also offset other costs (such as putting more Police on the streets).

As an example the UK Police are allowed to keep a percentage of the money raised from speeding and other fines raised buy the GATSO cammers.

However when one Police authority put speed cameras in unmarked vans there was a public outcry which resulted in the practice being stopped. An earlier out cry resulted in the GATSOs being painted yellow to make them more visable…

So anouncing cammeras for road tolls is not exactly going to be popular with the voters…

So how do you get the cammeras in place so you can then inflict the tolls. The ease way is to say “it’s for serious crime/ terorisum prevention” which as Bruce has kindly shown there are several scheams in progress in the UK right now.

Nobody has asked the UK governmant the obvious question, if these survalence systems are for crime prevention, as they are all very expensive where is the money comming from.

Clive Robinson April 16, 2005 8:15 AM

Opps sorry folks I forgot to fill in the name field before hitting the post button on the above Anonymos post

Jim Dermitt April 16, 2005 10:20 AM

The fewer data needed, the better the information. And an overload of information, that is, anything much beyond what is truly needed, leads to information blackout. It does not enrich, but impoverishes.

Another way to look at it is that if we give you enough rope, you can hang yourselves. The police who do this kind of work, don’t need guns. Some jobs are easier than others. A gun makes a good backup, just in case of blackouts or other unexpected situations.

Jim Dermitt April 16, 2005 11:02 AM

Gun security

Threat deterrent list.
1. Keep real bullets in the gun.
2. Don’t tell anybody about gun.
3. Keep location of the gun a secret.
4. Use deadly force when faced with deadly force.

If facing a criminal with a gun or other weapon, don’t pull out a camera and start taking pictures.

Gopi Flaherty April 17, 2005 5:08 AM

The British government doesn’t actually make license plates. They’re made by private companies, or anybody, really. This does make it a bit easier to impersonate somebody else’s number – you don’t need to steal it, just go to your local automotive shop, buy a kit with the plate and stick-on letters, and you’re good to go.

A bit of googling tells me that they now require that commercial vendors register, and put their post code (like a zip code, but alpha-numeric, and actually representing a single street) on plates they make. Still, however, it’s very, very easy to counterfeit a license plate in the UK. I wonder how prevalent it is among criminals?

stuart April 18, 2005 3:29 AM

As a resident of Essex I would welcome the police doing something about car crimes including driving without tax and insurance as well as vehicle cloning (Identify theft?)

But how does a helicopter help?

“Target acquired… Missile away… Target destroyed”?

Each time I fill up with petrol at my local Sainsburys they take a picture of my numberplate. This is to defend against drive-aways. They have signs up saying that they do it and I smile at the camera while waiting for the pump to engage.

Surely this would be a more practical place to make use of any kind of numberplate detection technology? Firstly you make it illegal to sell fuel to anyone driving an unlicensed or untaxed vehicle, just like it is illegal to sell alcohol to under 18s.

A team of touring police offices could then work round the filing stations and feel the collar of offenders. Good old fashioned policing and crime prevention.

There are massive car related crime problems in the UK. But measures to detect it are no use without measures to apprehend the culprits. Add to this the privacy invasion of “any-time, any place tracking??? and you see the eye in the sky is just fancy technology invading privacy and not a sensible crime prevention measure.

Rampo April 18, 2005 3:49 AM

One can buy UK number-plates here (for example):

Jim’s robust suggestion that life in the UK could be improved by forcing its gun-related death rate as high as that in the US may well be true, but before the police are able to shoot and kill speeders, they have to be able to identify them.

Some (scare-mongering) reports in BRitish newspapers have estimated that over 5% of British cars are using cloned identities now, partly because the state made enforcement of traffic laws (particularly speeding laws, through automated cameras) more rigorous, without doing enough to make car-identity cloning more difficult.

As Dr Schneier often points out, the security measures employed should be proportionate to the value of the asset protected.

Anonymous UK April 18, 2005 6:30 AM

One obvious use of such a system is to keep a lookout for particular vehicles. If a known vehicle needs to be found quickly then hovering an ANPR camera over a major arterial road would be one way of doing it (though rather expensive). The idea that the police use ANPR cameras as a money-making scheme is an urban legend, as they alert on particular licence numbers rather than on the speed of the car. GATSO cameras care about speed, but some drivers find it hard to understand that by not speeding they can avoid paying fines. Those who suspect the police of ulterior motives can defeat them via a campaign of civil obedience.

oliver April 18, 2005 8:55 AM

“Once the number plate has been successfully ‘captured’ applications for it’s use are limited only by imagination and almost anything is possible,”

We’re not necessarily talking about the intended uses of such surveillance being inappropriate. We’re talking about a system that can passively log the location of individuals at specific times (read Orwell, anyone?).

What’s even worse, though, is that all of this data needs to be stored in a warehouse somewhere. Have we learned nothing from the recent ChoicePoint, T-Mobile, and Bank of America debacles? What stops Bad People from accessing all of this data once it’s been logged? The best way to keep a database secure is not to maintain it in the first place.

Jim Dermitt April 18, 2005 9:03 AM

As advanced as our technological capabilites are, you still need people in the loop. Cameras require a great amount of data analysis to be useful. I think that generating terabytes of photo data is a neat academic idea.
You get to the point where you have more people dedicated to watching the camera data and less people watching real things. Then there are real budgets and limited resources. As the National Security Archive states, “However imagery is obtained, it requires processing and interpretation to convert it into intelligence data.” There is the limitation. We had good data and bad processing and interpretation which led to military mistakes. In the real time world of crime prevention and risk assessment, decisions have to be made on the spot at the time things are happening. Patrols have value because people are there who are trained and ready to respond, with deadly force if needed. In brief, don’t look for helicopters and cameras to replace patrol car units and human vision. Police have budget limitations and dedicating resources to high cost operations involving helicopters and camera systems isn’t a very good idea. I guess it works in the movies. Mere camera play. Cameras are great for people fighting fires and finding people in a smokey building or a confined environment. These cameras are expensive and there are not enough of them in the fire services. Budget restrictions again. Police process data based on what they can see and act on it as the situation commands. Firefighters face other challenges, so cameras are much more helpful for the situation they are likely to find themselves in or you could find yourself in. In this case a camera could save your life, the life of the firefighter or both. I’m not sure of how cameras will evolve with the needs of law enforcement. Thermal imaging cameras, which cost an average of $15,000 according to information I have. When you look in a mirror and see a patrol car, there should be eyes looking at you. I guess a camera is just optional equipment in this situation. Patrol mounted cameras are out there in force. You can always check the camera later. That’s smoke and mirrors. Stay safe out there guys.

National Security Archive Electronic Briefing Book No. 13

mjk April 18, 2005 10:06 AM

The original post and the others about restricting the use of technology because its “too easy” for police reminds me of the things people say about genetics and food, stem cells, nuclear power and any other place people see technology as the end of the world. The pandoras box of technology is open and there is no stopping anything from comming out. Get used to it.

Fridz April 18, 2005 11:23 AM

I don’t think it is reasonable to be against this sort of police technology just because it gives the police more powers. It is the job of the police to catch the bad guys and why should the police be barred from using hi-tech methods.

However, there are privacy issues, you probably do not want everyone to know where you as an individual are going. The real problem lies in who has access to this data and what will it be used for. Bruce points out that “… once the system is in place it will be used for privacy violations that we can’t even conceive of.” It is of course very likely that the police, or other parts of the government would like that in the future. But I find it rather a fatalistic approach to suggest that the system should never be installed in the first place.

This is solving the wrong problem. The problem is not increased police efficency through use of new technology. The problem is how the police/government can use this technology.

In many ways this is similiar to fingerprint technology. If this was something that was discovered today (that people have different fingerprints and they can be taken from an object after a person has handled it, stored, compared etc.), I do not think that anyone would suggest that the police should not use the technology because they would be more efficient in solving crimes.

There are numerous privacy issues that can surface with new technology. It can also be abused and create new kinds of crimes. But resisting the technology because of the potential new challanges is a bit like choosing to walk because a car can be stolen.

oliver April 18, 2005 2:12 PM

“In many ways this is similiar to fingerprint technology. If this was something that was discovered today (that people have different fingerprints and they can be taken from an object after a person has handled it, stored, compared etc.), I do not think that anyone would suggest that the police should not use the technology because they would be more efficient in solving crimes.”


The analogy of fingerprinting is apt. Despite what some members of the government are propsing, cataloging the fingerprints of all citizens does seem like quite a privacy issue, while using the fingerprints of suspected criminals by Warrant seems like a civil security tactic.

This article suggests that all license plates will be scanned and stored, not simply searching for suspected criminals.

Probitas April 18, 2005 2:30 PM

So once again, we have an admitedly poor solution to a problem, being sold for the wrong reason.

“This is all about denying criminals the use of the road. Using a number plate recognition camera from the air means crooks will have nowhere to hide.”

As has been pointed out, there are numerous ways around the proposed solution. How to get around it is not the relevant thing, nor is that fact that the system could be abused by overzealous law enforcement. The fact that the proposed solution actually does nothing to address the problem is the only relevant fact. Having plate recognition from the air does no more to stop crime than fighting a war in Iraq stopped Osama Bin Ladin. There is no connection between the problem and the solution.

Tom April 18, 2005 4:05 PM

Most posters are giving too much credit to the criminal here.

Car crime is a big problem in Essex, mainly perpetrated by youths with too much time on their hands. It’s unlikely these target criminals would ever think to change/obscure/remove the number plate before going for a joy ride.

It’s a solution to a particular kind of crime by particular type of criminal.

David Robinson April 18, 2005 5:04 PM

The Roads and Traffic Authority in the state of NSW Australia has a network of fixed cameras that are able to read number plates. The cameras are mounted on a gantry above the roadway and are well sign-posted.

The stated purpose of the system is to enforce travel times for heavy vehicles. But presumably the cameras are able to read other number plates as well.

The cameras have been operational since 1995, but you have to question their effectiveness, because there is a parliamentary enquiry currently underway to examine “fatigue management in the road freight industry”. Lots of juicy details are in the news. Drivers are frequently speeding and exceeding their prescribed driving hours, and up to 90% are using stimulants to cope.

israel torres April 19, 2005 11:55 AM

Here’s a better idea: Instead of chasing down criminals with this scanning technology, why not just refuse licenses to criminals? Cut out the middle-man entirely. 😉

Israel Torres

mrigank March 1, 2007 9:42 AM

i am doing project on rfid based intelligent vehicle license plate.i am facing a problem.i am inserting rfid tag in the no plate and there will be rfid card readers which will detect the vehicle.if the thieves
generate rf signal then they can easily detect that at which place the rfid tag is fixed and they can take it how to solve this problem.pls reply

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