back to article Car radars gain sharper vision after ITU assigns special spectrum slice

The International Telecommunications Union (ITU) has allocated the 79 GHz spectrum for use in motor vehicle applications. The decision, announced at the World Radiocommunication Conference, sets aside the spectrum on a global basis for use in collision-avoidance radar. Auto-makers, particularly those who make luxury models, …

  1. Pascal Monett Silver badge

    Interesting link

    Clear explanation on why the higher frequency is important : "A low-resolution system will have a higher rate of false alarms and will miss a small object that is in front of a big one".

    That is kind of important if you wish to avoid crashing into the kid crossing behind the SUV in front of you.

    Good things all around.

    1. Ru'

      Re: Interesting link

      Luckily my car utilises a passive 430–770 THz radar system when driving.

      1. frank ly

        Re: Interesting link

        Can yours penetrate fog? (Does 79GHz penetrate fog?)

        1. John Robson Silver badge

          Re: Interesting link

          Can your eyeballs penetrate fog? Not really.

          Why assume that this is the only system available - advantage of sensor arrays is that you can easily design a few of them - 79GHz, and optical, and IR, and???

          Some might not work very well in fog, but between them they will easily exceed the capacity of the plasmic scanner available to the current control system...

          1. Gotno iShit Wantno iShit

            Re: Interesting link

            The rules of the road are to drive such that you can stop in the distance you can see is clear. There is no need to see through fog if you observe this. If a person prefers to drive at a fixed speed regardless of conditions then technology that can counter their stupidity will be a boon. To them at least, the Gene pool loses out again.

            1. Yugguy

              Re: Interesting link

              Someone needs to tell this to the stupid cow in the Golf behind me this morning who insisted on glueing her car to my rear bumper despite a) me doing the speed limit and b) there being no way for me to go any quicker due to the many, many cars in front of me.

              I waved her past at an appropriate point and watched her glue herself to the back of the next car.

              1. Yugguy

                Re: Interesting link

                Shit she's still following me, she's voted me down.

              2. Queasy Rider

                Re: glueing her car to my rear bumper

                Although I like to generally drive 5 to 10 mph over the limit, I still try to maintain about double the spacing that my fellow drivers keep in traffic. If someone behind me is not happy with that and crowds me, I simply slow down to below the limit till they either back off, turn off, or go around. I firmly believe that there is no justification for tailgating a vehicle already going over the limit. Either pass or back off. I will not be forced to speed just because you are in a hurry. Of course the kind of driver that really gets my goat is the one that finally passes then drives no faster, or even slower than when they were behind you. They just can't stand coming second. I used to re-pass them just for spite, in my youth I wasn't afraid to drive in the triple digits if necessary to get back ahead of them, (I drove a 260 Z) but I'm(much)older now.

              3. Kamal Hashmi

                Re: Interesting link

                Saw that in the US once - the car in front simply braked and forced the car behind to slow down, then sped off again. I suppose having a gun in the car meant the car behind couldn't say too much....

            2. chris 17 Silver badge

              Re: Interesting link

              @ Gotno iShit Wantno iShit

              Having sensors able to see through the temporary fog caused by the bus pulling away would be advantageous to all. i see all sorts of numpties stepping off the curb behind big vehicles, expecting traffic to stop for them.

            3. Anonymous Coward
              Anonymous Coward

              Re: Interesting link

              > The rules of the road are to drive such that you can stop in the distance you can see is clear. There is no need to see through fog if you observe this

              I take it you're not aware (in spite of the article actually mentioning this) that radar systems are used for multiple purposes, including blind spot warning and rear collision detection?

              BTW, rule #1 of operating any sort of vehicle on land, sea, or air: humans are fallible. Always plan for human error and have a backup.

          2. Trigonoceps occipitalis

            Re: Interesting link

            "Can your eyeballs penetrate fog?"

            Don't know, never tried throwing them in fog.

      2. malle-herbert

        Re: 430–770 THz

        Don't you mean : 390 - 700 nanometer ?

        1. Ru'

          Re: 430–770 THz

          No; I was following the units of the article. :)

      3. Anonymous Coward
        Anonymous Coward

        Re: Interesting link

        > Luckily my car utilises a passive 430–770 THz radar system when driving.

        Mine uses two, only one of which suffers from fatigue, distractions, and the like.

      4. JassMan

        Re: Interesting link

        A trifle pedantic but I think that when you are using 430-770THz, it would technically be passive LIDAR since "radio" on which RADAR depends only goes down to 1mm (about 1THz).

  2. Chairo

    I always wonder...

    if this technology cannot be applied to create some low resolution "eyes" for blind people. Perhaps by mechanically transfering a picture on a sensitive skin area.

    It's 2015 and blind people still have to stumble around with a white stick in their hands like a hundred years ago...

    1. John Robson Silver badge

      Re: I always wonder...

      It's been done with a video camera and a 150? "pixel" square on the tongue...

      Allowed someone to go rock climbing IIRC...

      Edit: Added:

      BBC news link (2011)

      Discover Magazine link (2008)

      611 electrodes in an array on his tongue.

  3. MJI Silver badge


    Going from 12.5mm to 3.7mm wavelength

    Just over 3 times resolution

    1. The entire Radio 1 playlist commitee

      Re: Resolution

      But if you shrink the antenna by 3x (as the article suggests) then you get the same resolution you had before.

      1. A Twig

        Re: Resolution

        Yes, but if you shrink the antenna by 3x, you can then fit in 3 of them, making it 3x better... /sarcasm

  4. TheWeenie
    Thumb Up

    So a new car will have a head-up display and now radar as available options.


    Can I have a big, red button too please? Preferably with a flick-up guard...middle-lane moron locked on...Fox Two!

  5. tiggity Silver badge

    sort of repeating others but ..

    Alluding to fog comments, any EM wave real world use experts know what's the absorption of that short wavelength EM like by water droplets.

    Obviously its a noticeably shorter wavelength than a microwave oven (which is particularly good at being absorbed by water hence its cooking ability), it's only approx factor 10 difference, so would be interested to know if it is likely to be adversely affected by rain / drizzle / fog etc. (basically take your pick of lots of common UK weather)

    If absorption is quite high then you need car to have decent output power to compensate (otherwise a fairly limited range)

    1. Anonymous Coward
      Anonymous Coward

      Re: sort of repeating others but ..

      >shorter wavelength than a microwave oven (which is particularly good at being absorbed by water hence its cooking ability),

      Something of an urban myth that 2.45 GHz is special for water absorption. It's in a good area of the EM spectrum for the purpose, granted, but it's no better or worse than other frequencies nearby.

      "There's nothing special (like resonance), when it comes to absorption of microwaves by water at 2.4 GHz"

      "The frequency choice was based on a combination of empirical measurements of heat penetration for various foodstuffs, design considerations for the size of the magnetron, and frequency considerations for any resulting harmonic frequencies."

      I believe early experiments used the band (mainly for the 2nd and 3rd reasons in the paragraph above), then it became a general ISM band afterwards once it was already in use.

    2. Jonski

      Re: sort of repeating others but ..

      "...would be interested to know if it is likely to be adversely affected by rain / drizzle / fog etc."

      The new system picks up rain / drizzle / fog just fine, but when you've got the wrong kind of snow, or leaves... watch out!

  6. Christoph

    OK this band is reserved so there should be no direct interference with other devices, but what about interference with the radar on other cars? In heavy traffic there could be dozens of competing radars bouncing around.

    Also interference isn't just a matter of the same wavelength. When these radars are common there will be lots of energy in this band, in continually changing patterns as the transmitters move. That is going to produce some very weird effects on other devices even if they are not tuned to that particular waveband.

    1. Bronek Kozicki Silver badge

      I think that's why they reserved 4GHz , meaning there should be space for plenty off reasonably-sized bands for individual radars to use.

      1. chris 17 Silver badge

        Also the signals will likely be coded per car

        1. Christoph

          Coding for each unit works fine for low power, but these are radars - is it really going to be interference proof in the middle of Picadilly Circus?

          1. IvyKing

            With 4GHz of spectrum available, there's lots of opportunity for spread spectrum processing gain. Think CDMA cellphones in tight quarters.

            One of the goals of the larger bandwidth is allowing for better distance resolution. Should be alb to get 10cm fairly reliably.

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