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FCC Lets Radar Company See Through Walls

Posted by samzenpus on from the x-ray-specs dept.

DesertNomad writes "Attorney Mitchell Lazarus over at CommLawBlog gives a good overview of a new radar technology and the challenges of getting regulatory approval, which seemingly can be just as difficult as developing the technology itself."

9 of 179 comments (clear)

  1. Resolution by worip · · Score: 3, Informative
    3.5GHz translates to a ~8cm wavelength (maybe a bit less with the speed of light being slower in air). Resolving features that vary in amplitude of say less than 2cm (breathing and swaying) requires VERY accurate phase detection and time measurement equipment. Which translates to some very fast hardware doing phase correlation etc. From the article:

    Instead, the L-3 CyTerra device sends pulses on 200 different frequencies, one at a time, ranging in sequence from 3101 to 3499 MHz at 2 MHz intervals.

    and

    The system is sensitive enough to detect the chest motions of a person who is unconscious but breathing, or the slight swaying of a person trying to stand perfectly still

    --
    A picture is worth exactly 1024 words.
    1. Re:Resolution by bkr1_2k · · Score: 2, Informative

      3.5GHz translates to a ~8cm wavelength (maybe a bit less with the speed of light being slower in air). Resolving features that vary in amplitude of say less than 2cm (breathing and swaying) requires VERY accurate phase detection and time measurement equipment. Which translates to some very fast hardware doing phase correlation etc.

      That doesn't require particularly fast hardware for phase correlation at all. It's all relatively easily done in a small FPGA. Not cheap (if you consider a few thousand dollars per chip expensive--- L-3 does not, I guarantee that) but it doesn't require a lot of work to design. L-3 has very good FPGA design teams and has been doing phase correlation and time measurement for decades for use in radar systems. The only thing new about this is the frequency hopping that they're using to do it, and that's not too far out of normal for them either...

      --
      "Growing old is inevitable; growing up is optional."
  2. Re:Can it detect plants (or herbs) ? by jank1887 · · Score: 2, Informative

    TFA mentions that the device sorts the radar returns from moving (even slightly moving) objects and dumps the rest. It's a motion detector. that is all. smoke on, good sir.

  3. Re:Can it detect plants (or herbs) ? by JohnQPublic · · Score: 2, Informative

    TFA says "the circuitry combines the echoes at different frequencies", but I suspect "circuitry" is a layman's term and that this is truly done in software. Various DSP chips would be excellent platforms with which to do so. If so, then the starting point is a "RADAR camera", which gets turned into a motion detector through image processing. In which case those plants will be quite visible, along with anything else that has edges. The stolen Van Gogh on the wall, however, will be indistinguishable from Dogs Playing Poker.

  4. Re:Must be deployed only with court orders. by srollyson · · Score: 5, Informative

    The Supreme Court ruled that thermal devices require a warrant in Kyllo v. United States. I'm sure this radar system will follow precedent.

  5. Re:how many watts of power by BlueStrat · · Score: 2, Informative

    Radar isn't the kind of radiation that causes damage. It passes harmlessly through you.

    I'm sure that's what a few Darwin-Award-winning Amana RadaRange owners thought, too, when they decided to defeat the door interlock to "watch the food cook". The poor blind SOB's. Radar energy can cause your cornea to heat and become cataract-like.

    No, as a former civilian avionics tech that worked on radar, it can cause blindness/serious injury/death (depending on TX power and exposure time) if you're close to the business end of the antenna/dish of a radar transmitter.

    Strat

    --
    Progressivism (aka US 'Liberalism'): Ideas so good they need a police/surveillance-state to enforce.
  6. Article is misleading on primary use by amstrad · · Score: 3, Informative

    The article is misleading with regard to the primary use of this device. The device was developed for military use in urban combat situations.

    EMMDAR: ElectroMagnetic Motion-Detection And Ranging

    It was developed because infantry were holding up standard handheld mine detectors (AN/PSS-14) that use ground penetrating radar against walls trying to determine threat levels in neighbouring buildings or rooms. Troops would then interpret the audio tones to determine rooms contents.

    This device simply makes that technology smaller and more accessible and includes DSP algorithms to display potential threats (i.e. movement) on a graphical display.

    Other common uses for this device is search and rescue, both military and civilian. Of course the FBI and SWAT is going to want this technology. Any time law enforcement is going to assualt a building, this device is going to prove invaluable in saving lives.

    Nobody is going to pratically use this device for random checking of homes.

  7. Re:Stop scaremongering by GrumblyStuff · · Score: 2, Informative

    Video of said bust: http://www.liveleak.com/view?i=dc9_1228632109

    Small article and clip of local news coverage on it (might want to turn the sound down, some dope cranked it way up for the video). http://reason.com/blog/2008/12/06/gotcha

  8. Re:do not want by QuantumRiff · · Score: 2, Informative

    No, tazers were originally billed as an alternative to shooting, IE, the cop would only Taze someone in a situation where they would otherwise use deadly force. It was ONLY going to be used for such purposes, and since it has been approved by every police agency in the country, suddenly, its being billed as a great way to Subdue suspects, get them to comply with orders, etc.

    --

    What are we going to do tonight Brain?