Two basic types of radar are used - stationary and moving. Stationary radar must be used from a static site, typically a patrol car parked along side the road (See above figure). But with a single antenna moving radar, an officer can clock approaching vehicles while driving on patrol. Moving radar with two antennae - one facing forward, the other aimed out the back of the cruiser - can also clock vehicles even after they have passed by, headed in the opposite direction.
Q: How does a radar detector work?
A: A detector is a radio receiver tuned to specific frequencies
used by police radar. It is extremely sensitive, often able to hear radar
from over a mile away, far beyond the range at which radar can clock a
vehicle's speed. In evaluating a detector, the two most important performance
criteria are sensitivity and selectivity. Sensitivity is a measure of a
units detection range. Selectivity refers to a unit's ability to reject
non-police microwave signals and is an important feature because of the
many sources of "electronic pollution". (Note: Automatic door openers and
some burglar alarms operate on X-band, which is a police band. A radar
detector cannot tell if a store is opening a door or a police officer is
checking speed.)
Q: How common is the use of police radar?
A: Since the mid-seventies radar has served as the tool of choice
for speed enforcement. Over 100,000 radar units are in service by police
in all 50 states and account for over 37,000,000 speeding tickets each
year. In fact, there are so many radar guns on the road today, your speed
may be radar monitored more than fifteen times during a single trip from
New York to Los Angeles.
Q: What Frequencies are used?
A: Except for a few early units, X band (10.525 GHz) was the
only frequency used for police radar until the mid 1970's. In 1976 radar
guns using K band (24.150 GHz) were introduced; this led to the development
of the first dual band (X/K) radar detectors. A proliferation of radar
guns using Ka band frequencies began in 1987 with the introduction of photo
radar (34.3 GHz) and was followed by the Stalker (34.2 - 35.2 GHz) in 1991
and the BEE 36A (33.4-34.4 GHz) in 1992.
Q: Why are radar detectors described as dual band, triband, wideband
or superwideband?
A: Early detectors needed only to listen for X band radar. When
K band arrived, dual band models able to receive both frequencies (X and
K) were required. The introduction of Ka band photo radar (34.3 GHz) led
to the development of triband models able to detect X, K, plus a small
portion of Ka band. A fourth category of radar receivers called wideband,
with X, K and "wideband" Ka (34.2 - 35.2 GHz) detection capabilities reached
the market following the introduction of Stalker radar. And finally, in
response to the BEE 36A a new generation of radar detectors were developed
termed superwideband, which cover all radar guns operating on X, K or "superwideband"
Ka (33.2- 36.0 GHz).
Q: What is a false alert?
A: A number of transmitting devices are also allowed to operate
on the same frequencies used by police radar. These are not considered
false signals. For example, the automatic door openers commonly used by
business are low powered X band transmitters. They produce signals that
appear legitimate to a radar detector and cause it to alarm. Other sources
produce "harmonics" signals, ghosts or look-alike K or Ka band radar signals
which make a radar detector give a false alert. A better radar detector
reduces these types of false alarms.
Q: What is "pulse" or "instant on" radar?
A: When radar detectors proved easily capable of sniffing out
radar from miles away, radar gun manufactures responded by producing instant-on
radar. In the instant-on mode, the radar's transmitter is placed on hold,
ready to fire but not yet producing a signal for detectors to hear. The
officer waits until his target is very close (brings a new meaning to "wait
till you see the whites of their eyes") releases the radar from stand by
mode and gets a speed reading within a second or so. In this situation,
no detector offers much warning. TIP - When traveling in unknown
highways always try to find a vehicle which is traveling at the same rate
or faster than you are and keep several car lengths behind them. This way
the other vehicle can "flush out the radar".
Q: How does a laser detector work?
A: Since laser guns use a specific light frequency, it is possible
to detect a laser's signature light pulses. Keep in mind that laser detectors
act differently than radar detectors. Since the narrow laser beam produces
very little "scatter"-random bits of electromagnetic energy bouncing down
the road- it is much harder to detect than a powerful radar gun that blankets
the countryside with easily detectable microwave signals. Laser guns operate
exclusively in instant-on mode and usually target vehicles at short range.
The result is your laser detector usually will offer less advance warning.
Similar to instant on radar, if you are the target vehicle don't expect
much warning.
Q: How common is the use of laser for speed monitoring?
A: Less than 1,000 laser guns are in service in 45 states at
present. Most are used by city police on urban multi-lane roadways although
some state highway patrols-Illinois and Ohio to name two- have dozens of
units spread throughout the state. The use of laser guns for speed monitoring
is expected to increase, but will remain limited due to their high cost-four
times that of a moving radar-and limited attractiveness to agencies that
favor the convenience, offered by conventional moving radar. Currently,
laser guns account for less than 5% of the total number of speed monitoring
guns (radar and laser) sold in the U.S. annually; during the next five
years, this figure is expected to remain under 8%. Laser guns will likely
be in service in every state within a few years.
Q: Will laser guns replace radar?
A: No. Their premium price, limited applications (compared to
moving radar), and more complex operation will keep sales of laser guns
at a much lower level than radar.
Q: Do laser detectors "false" like radar detectors?
A: Top selling detectors use sophisticated signal processing
and optical filtering to almost totally eliminate laser falsing. Because
of the design's incredible accuracy, assume any laser alert received as
valid.
In Virginia, the largest user of the VG-2, officers are not empowered to search a vehicle unless visible signs are present to support the RDD's guess that a radar detector is in the targeted vehicle. A missing cigarette lighter plug, dangling power cord, Velcro on the dash, a mounting bracket on the windshield or visor will tip the officer as to the possible presence of a detector and allow him to search for it. If found, the detector isn't confiscated; the officer notes its serial number, checks to see if it's operational, then hands it back to the driver- along with a citation for having used it.
Q: Where is the VG-2 used?
A: At present the police in Virginia, New York, Illinois and
the five eastern Canadian provinces employ VG-2s. Because of the recent
FHwA regulation which prohibits nationally the use of radar [and laser)
detectors in commercial vehicles, interest in the use of VG-2 by law enforcement
agencies has increased.
Q: Can an officer detect my undetectable radar detector?
A: Big YES! There is a new receiver that the officers can use, its called Spectre! It's designed to receive
the signal that all radar detectors emit. These undetectable radar detectors were designed to only out smart the VG-2. Currently, with
the new Spectre model, no radar detector is safe. Just don't take my word on it, check out speedzones.com
Q: What is "pacing"?
A: Pacing is the granddaddy of all speed measuring techniques.
The officer typically drives up behind the target, accelerating until his
speed matches the speed of the target vehicle. His calibrated speedometer
then verifies the target vehicle's speed. Although pacing also works when
the police cruiser is in front of the target vehicle, some courts consider
this approach unreliable and won't allow it. Pacing is especially effective
at night, but rarely works when the drivers maintain a close watch in their
rear view mirror.
Q: How are aircraft used to monitor speed?
A: Using white reference marks on the road, the airborne officer
simply times the target between two of the marks to establish average speed.
Most states use VASCAR (a few use stopwatches), first programming in the
known distance between the marks, then operating the time switch to determine
target speeds. Cruisers waiting below stop the violator and write the ticket.
Contrary to popular belief, radar cannot be used from aircraft.
Concerning trucks over 10,000 lbs., the Federal Highway Administration (FHwA) issued a regulation, effective January 19, 1994, which prohibits nationally radar and laser detector use in these types of vehicles.
Prior to the FHwA regulation, laws existed in the state of New York restricting the use of radar detectors in trucks over 18,000 lbs. and in Illinois in trucks over 26,000 lbs. These laws remain in effect. In Canada, radar detectors and laser detectors are illegal to use in Manitoba, New Brunswick; Newfoundland, Ontario, Prince Edward Island, and Quebec.
Q: What can I do to keep radar and laser detectors legal?
A: Fight for your rights. Specifically, watch for news stories
about any legislation in your state that seeks to ban the use or sale of
detectors and let your elected representatives know your feelings. Don't
ignore such legislation even if it targets only heavy trucks. A favored
tactic of the anti-detector forces-primarily large insurance companies
who benefit immensely from slapping surcharges on ticketed drivers-is to
first go after truckers' rights to use detectors. If successful in banning
detector use in trucks, you can bet their efforts will turn to banning
in cars.
These safety radar transmissions are received by all radar detectors
because they transmit on K-band frequency, however, only newer radar detectors
with safety radar capability can identify them.