Police RADAR: How it’s Used & How you can Beat it


Police RADAR

How it’s Used & How you can Beat it

Updated: 03-10-2015

RADAR is an acronym for RAdio Detection And Ranging.

Unlike police lidar, police radar directly determines a vehicle’s speed by measuring the doppler shift of the return of its transmitted frequency (think of the sound you sometimes hear of an approaching or receding train or emergency vehicle). 

Police radar can be operated in two modes.  The first is continuously transmitted or constant-on (CO) operation. Generally radar such as this is easily detected at great distance with a radar detector. 

There are certain speed traps that utilize CO radar that are designed to be very hard to detect.  Police can operate constant-on radar from a “covered” position—hiding amongst heavy foliage of a median, for example, and pointing their gun across the roadway and not directly at approaching vehicles.  Such trap configurations can be very hard to detect even with the best detectors. It is not uncommon to encounter state troopers in New Jersey operating police radar in this manner.

The second mode of radar operation is called RF-hold, more commonly known as instant-on radar or IO radar.  This method of police radar operation began to appear in the early 1980’s as radar detector usage grew in popularity and it’s use is designed to specifically defeat drivers who operate a radar detector. 

A radar detector can’t alert to a signal that is not there.  Unlike constant-on radar, a radar gun is triggered by an officer who must first visually see your vehicle.  This form of police radar can be especially lethal when operated during the cover of night or from an on-ramp or overpass.

Radar guns operate on three frequency bands: X-band, K-band, and Ka-band.  Most newer police radar guns operate on the super-wide Ka-band.  K-band is still quite common, given its historical advantage to Ka-band. The oldest X-band radars, which have been widely used throughout the state of NJ, are being replaced with newer and smaller digital (DSP) Ka-band radar and even more lethal police laser guns.

Radar transmissions are quite wide in their dispersion patterns and are often reflected in many directions.  This gives a radar detector a lot of opportunities to detect the radar transmission and as a consequence generally provides the driver ample reaction time to slow down while vehicles ahead are being targeted.

Police radar is also not particularly precise in pinpointing which vehicles are responsible for speed readings, requiring a visual confirmation by officer. Some European police speed radar—called Gatso and Multanova—are much narrower, ultra low-powered, polarized, and much harder to detect as a result even with the best radar detectors. These systems can be fixed or mobile.  

Police radar can be operated in a stationery position or moving vehicle.  Most states allow radar to be operated by a patrol officer while driving.  Radar used in this way, can be quite challenging especially when operated in IO mode as a driver can come upon an officer on the highway around the bend and approaching in the opposite direction.  This can make for a difficult ambush situation.  

Radar can also be used in unmarked patrol vehicles making early detection even more difficult.  The state of Pennsylvania is unique in that only state troopers are able to use police radar and only from a stationery position.  In other states, both state and local police are permitted to operate radar as a means of traffic enforcement.

Police radar—even in I/O form—when transmitted is fairly easy to detect from ahead with a good radar detector and is one of the best tools a driver can use today.  The quality of radar detectors have improved dramatically over the years and even budget priced models, such as the Whistler CR90 can be a very effective device in mitigated its risk.  Higher-end (with price tags to match) are available from Beltronics, Escort, and Valentine Research.

POP radar from MPH Industries was marketed to change that.  If you think of radar detectors as specialized radio scanners, you will understand how POP radar sought to render them ineffective or at least give that appearance to municipalities who considered purchasing MPH’s radar guns so equipped.

The idea was simple in principle: if a radar gun transmits a single radar transmission lasting in duration for only 67ms, conventional radar detectors wouldn’t be able to detect a radar transmission of such short duration since they are spending time sweeping (scanning) the multiple bands (of X, K, and Ka) that all radar detectors must continually do.

While the 67ms version of POP radar has essentially been mitigated by all of the major detector manufacturers today – most detectors now have specialized circuitry to specifically detect it—MPH has introduced an even quicker version of POP radar that’s rated at a blistering 16ms (that’s 16 one-thousandths of a second!).

Even the mighty Valentine One radar detector – arguably the best detector for identifying POP, struggles with this form and alerts to it only about one out of every 10 bursts. We have seen POP used more than once and have found that, indeed, it was capable of making accurate readings.  That’s not to say it was not infallible.

Valentine Research (they know a thing or two about radar) has suggested MPH’s technology has been flawed and prone to error. Interestingly enough, MPH’s site has modified their website POP section indicating that speeding citations can not be issued solely on the use of POP.

We originally saw the potential of POP—allowing for traffic enforcement to be able to take spot-readings of traffic as a means of furtively taking speed readings prior to using the conventional operation of instant-on radar for the purposes of issuing citations.  In the final analysis, POP never became widely used and its theoretical advantages have been trumped by the proliferation of inexpensive police laser (LIDAR) guns which are much easier to operate and are far more lethal to us motorists.

Attempting to jam police radar is a federal offense and although the equipment that has been available over the years, with very few exceptions, have had shoddy construction quality. 

As mentioned earlier, your best bet is to invest in a good radar detector. Today’s police laser guns provide the same advantages of stealth operation and offer very quick acquisition of speed (provided you are not using a countermeasure like VEIL). They also have the distinct advantage that tickets may be issued to potential speeders with every trigger pull.

Police radar is also not efficient at determining a single vehicle’s speed when there are many vehicles on a crowded highway.  With police laser, the officer can specifically target your vehicle in much the same way a sniper with a scope does. 

Since laser is a highly focused beam of infrared light which barely encompasses the front of your vehicle even at a far distance, it makes advanced detection by other detector owners very difficult. Police laser is often operated at greater distances than police radar and that fact makes police laser a much more a lethal form of traffic enforcement technology.

The powerful combination of instant-on usage coupled with no advanced warning is the real threat of police laser.  Even detector manufacturers acknowledge that laser detectors when used alone have “little” value.

Fortunately you do have the ability to turn your detector from being ticket notifier into ticket preventer when you use Veil to protect you.