Hackers Underworld 2: Forbidden Knowledge/Hackers Underworld 2: Forbidden Knowledge.iso/HACKING/RADAR

Text File | 1994-07-17 | 15KB | 269 lines

[ -------------------------------------------------------------------------- ]
[ -          The Modern Speeders Guide to Radar and State Troopers         - ]
[ -                             By : Exilic Xyth                           - ]
[ -                             January 11, 1988                           - ]
[ -------------------------------------------------------------------------- ]



         Introduction:

                   Touched off by the discussion on Ripco <312>-528-5020, I
 found many users asking questions about police radar, radar detectors, and
 speeding.  With Ron Majors talking about the oil spill that will appear in
 detail on the news at ten I thought a informative file on the subject might
 be beneficial.  I myself had my first experience with police radar in my
 fathers car, then following in baseball and my own driving, much more on the
 subject.  What a fascinating device, that it will return your speed instantly,
 what fun one would be to have!  After a quick talk with a police friend of
 mine, I soon took possession of a used police radar gun.

         Part one: Operation.

                   Police Radar works via the doppler effect, best
 demonstrated by sound rather than microwaves.  The doppler effect is the
 relation of speed to the pitch of 'sound'.  Sometime, all of you must have
 had the distinct pleasure of being honked at by a motorist on the go,
 you might have noticed that the horn <an F flat on most american cars>
 begins with a higher pitch and as the car passes, drowns off to a lower
 tone.  The sound waves at the front of the car are pressed together by the
 forward motion of the car, creating a higher pitch.  As the car passes,
 the tone dies off to a lower pitch because the waves are spread out.
 Police radar works in much the same way.  The major differences are the
 frequency and the concentration of the carrier.
                   As of 1988, the F.C.C. is rumored to have lifted restrictions
 on police radar frequencies.  Before, only two frequencies were approved for
 police radar use.  X-band <10.525 GHz> which is most commonly used, and
 K-band <24.15 Ghz>.  I will assume for now, due to lack of any SOLID evidence
 supporting the restriction lift, that those are the only two in operation.
 Police radar 'beams' are similar in shape to a flashlight beam.  They begin
 with a thin width and cone outwards with distance. Most guns operating at
 the X-band level have a range of about 2000 ft., although high power units
 can exceed 2500 and 3000ft., and K-band guns fall shorter at about 1200 ft..
 At 1500ft., the radar beam becomes about the width of four highway lanes, so
 for practical purposes radars range is around 1700 ft..  A radar signal
 transmitted from the 'Radar Gun's' transmitter, (called the oscillator) will
 bounce off a object and return to the radar receiver (or antenna).  If the
 object is moving, the frequency of the beam will be altered as it bounces.
 This is most easily visualized watching water ripples.  Assume now that I
 have just dropped a pebble in a pond, and the ripples are moving outward,
 assume also for purposes of simplicity that the ripples are moving at
 1 foot per second, and that they are one foot apart.  The ripples are
 therefore also one second apart.  Upon bouncing off a stationary object
 the ripples will return weakened, but at the same interval and speed
 <Not really the same speed, but let's not complicate things>.  Now let
 us assume that a toy boat is traveling in the water at .5 ft. per second,
 1/2 the speed of the ripples, away from the point which I dropped the
 pebble.  Assume the first ripple has hit the boat and is traveling back.
 The second ripple now traveling at 1 foot per second is only gaining on the
 boat by .5 feet per second <1 ft. per second - .5 ft. per second>.  This means
 that the ripple is one foot away from the boat, as the ripples are one foot
 apart.  The ripple will take 2 second to reach the boat, as the closure speed
 is .5 ft. per second and the distance is 1 foot.  The ripple strikes the boat
 and bounces back two seconds after the first ripple.  The process works
 inversely for an object moving towards the pebbles point of impact.
 As the distance between the ripples can be determined by the speed, on the
 other side, the speed can be determined by the distance between the ripples.
 Police radar works in the same way with microwaves.  The microwave signal
 bounces off a moving vehicle and returns altered in frequency.  In this way
 the radar unit determines the speed of the object.  Radar is only accurate
 when the object is moving directly at, or directly away from the gun,
 although some modern guns will account for this 'COSINE error', most won't.
 Cosine error can be defined as this:  When a radar signal bounces off an
 object at an angle from the objects direction of travel it will return a
 portion of the objects speed computed by the cosine of the infraction
 angle.  If the angle of the objects direction and the radars direction is
 20 degrees the speed returned by the radar is 93.97% of the objects
 actual speed.  cos (20) = .93969262 * objects speed = returned speed.
 For example:  A car is traveling at 75 m.p.h..  The state trooper, in his
 infinite wisdom, decides to "Clock" the automobile in hopes of meeting his
 quota for the month. Picking up his handy radar gun, he aims, and fires
 an invisible beam of microwave energy.  The officer however, being the rookie
 he is, leaves a high angle between the cars direction and his beam of 45
 degrees.  Cos (45) = .707106781  .707106781 * 75m.p.h. = 53.03300859
 53 m.p.h. is displayed on the officers screen.  Lucky motorist.
 Sorry 40 column users.

         |
         |\
         | \
         |  \        - Cosine Error -
         |   \
         | 45 \
         | deg.\ - radar beam
         |      \
         |       \
         v        \
    Direction of   \
     cars travel    \
                     \
                      X - state trooper.

         Part 2: Application

                   In 1986, over 15 million speeding tickets were issued,
and experts estimate that over 25% of them were in error.  Police have
been using radar for speed control for many years, and as the technology
has become more complex and accurate, so has the ability to get away with
the slight infractions of the speed limits set by the government become more
difficult.  In recent years, the three most damaging advances to motorists
in radar technology include:  A> Instant on radar.  B> K-band radar. and
C> Cosine error correcting radar units.


                   Instant on radar.
                             With the increase of radar receivers, or
"Detectors" on the roads, police have attempted to bypass the motorists
first line of defense.  The most damaging advance in the war against speeding
motorists is instant on radar.  The idea behind instant on radar is to make
the radar detector useless to the motorist by making his warning too late to
react to.  Instant on radar was developed in early 1983, but never marketed
until late 1984 when the michigan state troopers were equipped with the first
instant on radar guns.  It operates by deactivating the oscillator until
triggered by the officer.  When used properly and under the right traffic
conditions, it is indefensible.  It works like a camera, the officer
operating the radar will position himself behind a blind corner or over a
hill.  When the approaching car crests the hill or rounds the corner, the
officer will activate the oscillator, taking a "snapshot" of your car.
As microwaves travel at the speed of light, any attempt at slowing down
is futile, the officer behind the gun has your speed in less than a tenth
of a second.

                   K-band Radar.
                             When radar detectors were first marketed by
the markers of ESCORT, there was only one type of radar.  X-band.
In an attempt to increase the dwindling speeding ticket revenue, K-band
was brough