Heathrow Radar Emissions

[B Fraser]

Is there some sort of covert car surveillance in operation around Heathrow ?

I fitted a radar / laser detector to my car some time ago following an interesting session with a magistrate who decided I didn't pay enough tax After installing the device, I tried to set it off with a laser pen to test all was well however the device only responds to the infra-red end of the spectrum.

The only place I can find where the detector is triggered is around Heathrow... every hundred flippin' yards. The device is also set off at key road junctions close to the airport e.g. the bottom of the A30 at the Egham bypass roundabout. Is there some device such as the MLS which interferes with detectors or has Q devised some sort of system to screen all vehicles approaching the airport and track their progress around it ?

Thanks !

[lhr_slots]

The ATC radar sweeps round about every 2 secs. That could cause your detector to go off every hundred yards?

[B Fraser]

Thanks Slots,

I though about that but there are areas where I have line of sight to the radar and the detector is not activated. Radar altimeters have also been ruled out.

Road junctions at the roundabouts south of T5 always set the device off making me think that there's something strange happening. There are no traffic lights so there goes another theory.

[FakePilot]

Automatic doors will set off radar detectors too.

[Seloco]

Er, if it is a radar detecting device why should it respond to "the infra-red end of the spectrum"?

On the other hand, if it really does, then maybe it is simply relishing all those nice hot turbofans that dash past every two minutes or so......

Sadly though I suspect that answer is rather more prosaically related to the myriad of radar gizmos that are pulsing away around LHR.

[B Fraser]

Automatic doors will set off radar detectors too.

Not many roundabouts have them ! The detector is the Origin B2 so it's very much at the high end of the market. Perhaps I should add that I drive around 60 miles to work and back through villages, traffic lights and past all sorts of emission sources but absolutely nothing else will set it off.... other than a policeman gainfully employed (not) in generating revenues for Gordon Brown.

why should it respond to "the infra-red end of the spectrum"?

duhhh.. sorry... I've been in the office since dark o-clock this morning. It's a laser detector. I'll crawl back under my stone.

[HEATHROW DIRECTOR]

<<The ATC radar sweeps round about every 2 secs. That could cause your detector to go off every hundred yards?>>

Close, but not quite - it would take off! The big one by the tunnel sweeps about every 5 seconds if memory serves me.. i.e. 12 times per minute. The surface movement radar is much, much faster but does not have the same transmission power as the big boy... (Yet again I look to current colleagues to put me right!)

Irrespective of what detector it it, it's probably of very poor quality and wide open to anything so radar could be the cause. I'm a radio amateur and could tell you tales all night of equipment which receives radio signals but isn;t intended to - like electric kettles, hi-fi, deaf aids, church bells, etc!

[speedbird_heavy]

Should have bought a GPS based "Accident Blackspot" detector. The ones that recieve Radar go off every 5 seconds. Anything can trigger them from car key fob unlocker things, house alarms, car alarms, traffic lights, radio masts oh and speed camera's. Thats why I slung my old snooper. Even in "city mode" it went off all the bloody time. So I bought a GPS Road Angel unit. Update it via the web every morning and it will only make a sound near a camera site (even mobile) and it detects laser.

[EvoIV]

Should have bought a GPS based "Accident Blackspot" detector. The ones that recieve Radar go off every 5 seconds. Anything can trigger them from car key fob unlocker things, house alarms, car alarms, traffic lights, radio masts oh and speed camera's. Thats why I slung my old snooper. Even in "city mode" it went off all the bloody time. So I bought a GPS Road Angel unit. Update it via the web every morning and it will only make a sound near a camera site (even mobile) and it detects laser.

I think you should have looked here before posting

http://www.originb2.com/product/features.cfm

The reason people buy units with extra radar and laser detectors is because the GPS ones rely on somebody updating them. So they are great for fixed posts. If, however, plod are in their vans doing random areas (as they do round here), or are following you in an unmarked car, a unit which is solely GPS based is as much use as a chocolate teapot. As is any laser detector because unless you are really lucky and pick up a reflected or refracted beam you are too late to do anything about it. Once the laser has pinged it's game over, you can slow down but it won't help! Because the laser is focussed, you won't get any warning (with the above exceptions) until they target you. The only solution is a laser diffuser (commonly called a jammer) which opens you up to a gazillion different charges, some of them nasty. I don't use any of them, if I am caught speeding I deserve to be fined. My opinion will probably change if and when I am "done" for the first time.

To get back on topic, just a guess but it's possible that there are traffic flow sensors in the area so that those in the know have an idea of the flow rates electronically (rather than the little blue cameras you sometimes see, usually high up or on bridges. They usually use induced loops unde the road for that sort of thing though.

I suspect that it is, like others have suggested, some byproduct of all the gizmos at LHR. The locations are probably arbitraty. The radar could be bouncing off a plane, off somebody's car roof, onto a road sign and then on to you (bit exaggerated but you see what I mean)

[B Fraser]

The detector goes off at precisely the same location every time e.g. about 5 meters back from the give way line on a specific roundabout. The alarm is so predictable that I have learned when to reach for the cancel button so I'm convinced that there is some sort of monitoring going on.

I'll see if I can trigger the detector when I'm next in one of the huge car parks along the North perimeter road.

[slingsby]

Sorry to upset you but LHR and some of the surrounding area have some very specific electronic equipment. Number plate recognition systems are prolific around Heathrow, both front and rear readers, so your detector will probably be sensing these emissions while they read your number plate. Also don't forget that some traffic mapping systems do frequently monitor speed of vehicles passing under them, so they can advise users of known traffic blackspots. Also around Egham roundabout you are passing very close to the M25 which has speed cameras in the gantries and several on the road, during the roadworks.

[Loose rivets]

It must be nearly 40 years ago that a letter in Flight was titled ‘why weeeeee?' Or something like that. It referred to a sliding whistle on the car's radio wile heading into the outer reaches of the city. I had heard this many times, but the letter did not seem to get a satisfactory answer.

It seems that spurious radio signals near to LHR are nothing new.

[sycamore]

BF,the ban on all laser and radar speed detectors comes into force in the Spring; only GPS ones allowed after that !!

[FlyUK]

I have a laser/radar detector in my car, but find although pretty good at getting the pesky speed cameras, it does pick up CCTV cameras due to infrared and traffic lights due to the pedestrian radar bit.

[HEATHROW DIRECTOR]

<<It must be nearly 40 years ago that a letter in Flight was titled ‘why weeeeee?' Or something like that. It referred to a sliding whistle on the car's radio wile heading into the outer reaches of the city. I had heard this many times, but the letter did not seem to get a satisfactory answer.>>

It sounds like a heterodyne - when two AM stations are transmitting on the same or close frequencies you will hear a whistle on the receiver. This becomes most noticeable as darkness approaches and the range of AM transmissions increases so we start hearing stations Europe or even further away. The change in pitch or amplitude could be a function of range from the transmitter. It still happens - try tuning to AM signals around 12-1500khz in the late afternoon and you will for sure find one with a whistle as the range increases and continental stations start interfering..

[KES-rayman]

With some of the radar/Laser detectors you can use your TV remote to test the laser function,,
not always though..

[JEVON]

Detector Specifics

Depending on how old the radar detector is, it will definately pick up K band radiation (not sure of the exact frequency) and maybe even L/M if its a really old one. K band is used by gatso's and also by traffic signal detectors(they change when something comes close). The radar from the Airfield won't be picked up as this is well outside the frequency which your detector can pick up. The Gatso uses short Pulse repetition Frequency (PRF) and the ATC radars will be a lot longer in PRF in order to be able to detect signals from further away.

As far as the laser setector, it can be set off by Gas discharge headlights as these mimmic the laser light spectrum and can cheap detector can be fooled (by cheap I dont mean your detector is cheap but in comparison to military laser detection equipment it is) and also sunlight being focused of a car's paintwork or and glass object can also give false readings.

Out of curiuristy which detector have you got, as I have had a few in the last couple of years, I've also found ways to change the settings to make them more user friendly.

City mose if you have it, will fitler out all the traffic signal detectors and door openings.

Hope this is usefull. If anyone wnats to know more detail about the actuall frequencies I'll be able to give you the exact freq's of the bands (if your that desperate)

JEV

[Loose rivets]

BF,the ban on all laser and radar speed detectors comes into force in the Spring; only GPS ones allowed after that !!

It is with utter dismay that I read that a receiving device--of any sort, should be banned in the UK. Given that it does not radiate a signal, I feel very strongly that this in a serious reduction in our civil liberties...yet again.