Using Same Lane/Fastest mode, some Stalker and Kustom Signals radar models can easily target the yellow car, ignoring all other vehicles in the beam. The red car is
equally at risk. Conventional radars would see only the
back of the John Deere trailer ahead. |
A police radar gun operates by transmitting radio waves at certain frequencies. A portion of the beam reflects
from the target vehicle and returns to the radar. If the target is moving, a measurable change in frequency
occurs (Doppler shift). The radar converts this shift into miles per hour and calculates target speed.
Except for the earliest units in the fifties, X-band (10.525 Gigahertz) was the only frequency used for police
radar until the mid-1970s. K-band (24.150 GHz) arrived in 1976 and Ka band (33.4 - 36.0 GHz) appeared in 1989.
At present about 5 percent of the 100,000-odd radar in service nationwide use X band, 50 percent use K band
and 45 percent operate on Ka band.
Those percentages are shifting rapidly; today the majority of new radar
entering service is Ka- band and X band is fast disappearing except in a few holdout states like Ohio and
New Jersey whose state patrols invested heavily in X band radar years ago and are loathe to change. But
everywhere else there's a wholesale move toward Ka band.
Moving and Stationary Radar
Two types of radar are used--stationary and moving. Stationary radar must be used from a static site,
typically a patrol car or motorcycle parked alongside the road. (Photo radar, an automated system that
combines K- or Ka-band radar with a camera, also is stationary-only.) Stationary radar is easier for radar detectors to spot than moving radar. Target range is generally
under 700 feet, particularly in town. [Editor's note: See the latest radar in action--from inside the police car--in our new video.]
With moving radar an officer can clock approaching vehicles while driving on patrol. If the radar has dual
antennas--one facing forward, the other aimed rearward--targets in the opposite lanes can also be clocked after they've passed by the cruiser.
Newer radar models have two unique features, Same Lane mode and Fastest Speed mode. Both are very bad news. (How bad? See for yourself,
check out the new
video.)
A dual-antenna moving radar with Same Lane can clock vehicles ahead of or behind the rolling cruiser. But with the exception of a very few models, it cannot do so if any
vehicles are between target and the patrol car or if any vehicles faster than the target are within range, which can often be one half mile or more. So if you're paying
attention, a trolling cruiser is unlikely to
get close enough to employ Same Lane without being spotted, particularly if he fires at other targets before reaching you, triggering your detector. (At night, all bets are
off.)
Stalker DSR 2X can clock the speeds of multiple vehicles ahead of and behind the rolling cruiser. Here the display shows a 36 mph speed for the oncoming minivan at
far left and the 54 mph speed of the distant approaching SUV, the fastest vehicle in the beam. It has also locked-in a 54 mph speed of a vehicle behind the cruiser. At far
right the 51 mph speed is patrol (cruiser) speed. |
Fastest Speed mode is more of a problem since it allows the radar to sample multiple targets and display the speed of the fastest. With this feature an
officer can clock a motorcycle passing an eighteen-wheeler, impossible with conventional radar. If you're a high-roller and the fastest vehicle in a pack, this means you'll
no
longer be able to take refuge among other vehicles.
Target range, the distance at which radar can clock a vehicle, depends upon radar design, target-vehicle cross
section (frontal area), terrain, weather and a slew of lesser factors. Although I've used radar capable of
clocking 18-wheelers at 2.5 miles, practical range is far less. The useful target range of any radar is restricted to
no more than a quarter mile and more often, less than 700 feet, at least if the officer is following the rules.
That's because before using any type of speed-measuring hardware to check speeds, by law the officer must
first witness the violation--speed in this case--and visually estimate the target's speed. Only then can he activate
his radar to confirm that estimate. Many times an alert driver with a radar detector is more than a match for
radar. (But if the officer flouts the rules and simply fires at any target of interest, you can forget everything I just
said about target range.)
Oh come on, Bubba. Time to get off the couch and educate yourself before you get another ticket. Check out:
|
What to Look For
How to know when you're at risk? That also varies, depending upon key factors like the type of road, traffic
volume and state laws. For instance, if you're driving on a highway with a center divider, your biggest problem
will be stationary radar on your side of the highway. That's because a center divider (not a median) prevents the U-turn
necessary for a radar-equipped officer to work opposite-lane traffic in moving mode. He'll have to park at
roadside or sit next to the median.
If he's using a dual-antenna radar, common in patrol vehicles but not so much on motorcycles, he can alternate between the
front and rear antenna. With the rear antenna he'll use his mirrors to monitor same-direction traffic as they approach. After they've passed, he'll use the front antenna,
hitting them from behind as they depart. Given the brain-dead driving of most motorists, day or night, he's unlikely to be spotted, regardless of whether he's on a
motorcycle or driving a radar-equipped Mardi Gras float.
If he's more energetic, provided that traffic isn't too dense, he can cruise along in the slow lane and target
same-direction cars to the front or rear. This is known as Same Lane/ (or Same Direction) Moving mode. It's more work for the officer, and intervening vehicles will slow the
process or foil it entirely. But done properly, it's highly effective.
For example, my friend Bob, CEO of Laser Veil and a frequent blogger on the subject of radar tickets, called recently from outside Washington, D.C. He'd just been ticketed by a Maryland State Police
trooper on I-270. (I know these folks well. For my benefit they once pulled together a dozen patrol vehicles, a Cessna 182 patrol aircraft and a radar-equipped Ford tractor
used for speed enforcement, enabling me to gather source material for several stories. The picture on this Web site of a police aircraft is pilot Ken Cross and trooper Marc Price, taken that day.)
In Bob's incident, the MSP officer had been driving an unmarked black SUV in lane 3 (here the far-right lane). When Bob approached in his BMW, using lane 1 (fast
lane), the first hint of trouble was an urgent Ka-band alert. By the time he touched the brakes, it was over. Using a Kustom Signals Golden Eagle, the trooper had
selected the rear antenna and come off RF Hold by hitting the Transmit button on his remote. A target speed would have appeared within a second, two at the most. Bob
wasn't even able to identify the police vehicle until it pulled up behind and lit him up. Score one for Same Lane/Moving Mode radar.
Forty-nine states use radar similar to this. The moral: Learn about what you're up against. Or expect to suffer the consequences.
Oh, I beg your pardon. You already knew all this stuff? Okay, then let's test your radar knowledge
and find out how smart you really are. |
Radartest Blog: Breaking news and some irreverent opinions
