Microwave jamming

[telecat]

The Police reckon this could be their next "weapon" againest "car crime". So if somebody develops a jammer capable of stopping your cars ECU, how long before some toerag uses it to disable the following Police Vehicles, (including Helicopters:yikes:), carjacking or cause an accident.

[D_Mike]

Or you could just wrap the box with the engine management bits in it in tinfoil.

[Pigeon]

Or get a diesel. (A real one, with no electronics.)

[Darth Viper]

Or an older car, with no complex chips of any kind.

[D_Mike]

How do the police stand legally on using microwave jamming anyway... I thought all electrical devices had to pass a test to make sure they didn't emit harmful electromagnetic interference...

What if they blow up innocent people's equipment with them?

Whilst I'm asking these questions what is the legality of the police pointing powerful lasers at you/your windscreen when they use their speed traps?

[smeggy]

D_Mike said:

How do the police stand legally on using microwave jamming anyway... I thought all electrical devices had to pass a test to make sure they didn't emit harmful electromagnetic interference...

As someone who is familiar with EMC; all units for use ‘in service’ must be immune to RF up to a certain level (as well as not radiate), up to 'so many' volts per meter. Due to limitations of design resource, a field strength a small fraction more than this minimum limit will usually make the unit malfunction
A microwave emitter will very much exceed that limit.

D_Mike said:

What if they blow up innocent people's equipment with them?

A minor inconvenience, unless it causes an accident (power steering fails, no brakes....)

D_Mike said:

Whilst I'm asking these questions what is the legality of the police pointing powerful lasers at you/your windscreen when they use their speed traps?

LTI’s accepted argument was as follows:
While the lasers used in Lidar units are very powerful (~30 watts), the output pulse duration is extremely short - only a few nanoseconds (a few thousandths of a millionth of a second). Therefore the radiated energy is very small, not enough to cause eye damage; it’s about 3000 times less than the lesion threshold, even when viewed close to the emitter.

[ledfoot]

Some car alarms are aready prone to jamming from the Airwave radio transmitters as used by the police.

With the right kind of transmission it would in theory be possible to jam a cars ECU, but in reality these are well screened for obvious reasons to avoid such interference, so is quite unlikely.

[D_Mike]

Thanks for some interesting answers smeggy.

Do you know the divergence and the beamwidth for the laser in the speed traps?

[Cooperman]

I recently did some work with a company designing the latest generation tracking/monitoring equipment (not specifically for vehicles and definately not for private cars). It is currently illegal to have any means of remotely shutting down the engine of a vehicle, even if that vehicle is stolen or driving illegally. The reason for this is to prevent the vehicle from being stopped in a dangerouis location (lane 3 of a motorway, just over a blind crest, etc).
Personal view? It won't happen and, if it did, it would be easy to shield from anyway.

[FunkyNige]

How on earth would they 'shoot' in the right direction? I thought EMPs just went everywhere?

And how do they make sure they target the ECU and not the airbag system?

Not going to happen IMHO, it's more likely the GPS tags we're all going to get will eventually be linked to the ECU so they can shut it down remotely from there.

[alltorque]

D_Mike said:

Or you could just wrap the box with the engine management bits in it in tinfoil.

Ahhh, sounds like my old griff....

[smeggy]

D_Mike said:

Do you know the divergence and the beamwidth for the laser in the speed traps?

The answer will depend on who you want to believe.

“The usual description of the laser beam is four feet in diameter at 1000 feet”

“In 1995, three German engineers at the university in Erlangen tested the LTI 20-20 and two European laser guns. They found that the LTI had three beams side by side instead of a single beam, which raises doubts about what spot on the car is actually being tracked.”


(this makes sense considering the laser diode may be a 3 layer stack type)

That article can be read here, it is a very interesting read indeed. It should be made compulsory reading for all PHers!

www.moederdegans.nl/de_bologna_slice_kwestie.htm

edited cos my formatting was somehow lost

>> Edited by smeggy on Wednesday 7th September 15:26

[Peter Ward]

smeggy said:

That article can be read here, it is a very interesting read indeed. It should be made compulsory reading for all PHers! www.moederdegans.nl/de_bologna_slice_kwestie.htm

Truly frightening. Looks like LTI is getting the best justice it can buy. It does seem like the conspiracy theory is the right one in this instance.

[bryan35]

there's a pub up near filingdales moor (where the early warning/tracking/military installation is) where certain types of cars will not start if left in the car park. AA been called out there lots of times. Was some breed of 4x4 if I remember.

I also recall that the base used to emit radar pulses at a staggering ERP of 28MW.

Coincidence?

[echo]

The US have a trial system but it's a bit big!



Lookup 'Vehicle-Mounted Active Denial System' on google

for the lazy ones..
www.defense-update.com/products/a/ads.htm

[mel]

I thought the american plod already had a version of a "vehicle tazer" yes its connected to the gun by wires and doesn't rely on an EMC pulse, but I'm sure they fire it at the doors and it gives the car many 1000's of volts and kills all the the electrics, and the driver if you're lucky