> Mistakes of Police Radar
Mistakes of Police Radar
Did you know that over 25% of all citations are written in error?
Was your ticket one of these?
During my police career I became certified as an instructor in police radar and lidar enforcement and after my retirement back in 1996 began a website educating people just like yourself on how to avoid those costly speeding tickets using the various devices that are available in the speed counter measurement industry.
Since I received tons of questions regarding the various devices police use such as radar, laser, and vascar I have created this overview which will address some of the more frequently questions I’m asked.
Also a recommend resource if you plan on fighting your ticket in court, we have a more in depth article here titled “How to Beat Your Speeding Ticket in Court and Win“.
However before we begin, I want to stress a few important issues:
First off, as I mentioned, I am a retired police officer and regarded as an expert in both traffic enforcement and the speed counter measurement industry.
However I am not an attorney so please don’t contact me regarding legal advice!
It is my goal that our information will help you become more prepared and help you make a sound buying decision if you’re in the market for a radar detector and/or jammer.
Police radar transmits a radio wave in the microwave band that upon striking an object is reflected back to the radar gun and a “Doppler Shift” occurs in the frequency that is received back by the radar gun. The radar gun thus measures this change in frequency and then calculates the speed either in miles per hour or in kilometers per hour.
The Doppler Shift is a scientific principle that is used in both radar and laser enforcement in that the transmitted output of RF or radio frequency, a light wave or even an audio signal will increase or decrease in frequency based upon the movement of the target.
This change in frequency is predictable and is used to calculate the relative speed of the target. This same dropper principle is used by weather radar, sonar and even radio telescopes.
I Don’t Feel that I was speeding! – What Can I do to fight this ticket?
Well one of the first things to consider is something called Doppler Shift.
For an officer’s radar/laser gun to be accurate the officer should be at an angle less then 11 degrees.
If the officer shooting you at an angle greater then this, then speed that was displayed on his device is NOT ACCURATE.
Now depending upon the type of radar gun the officer was using determines who’s favor the inaccuracy favors.
Stationary Police Radar: If you approach the officer at an angle and maintain the same speed as you approach, your relative speed that was first measured will be the most accurate. However as you approach the officer and your angle increases thus the relative speed that will be measured by the gun will decrease.
Typically an officer’s angle should be less then 10 degrees from his target to obtain an accurate reading when using either stationary or moving radar. But again, if he exceeds this angle while in stationary mode, the odds are in your favor, not the officers.
Moving Police Radar: Now if the officer is using moving radar things become a little more tricky.
Moving radar was developed so an officer could measure speeds of approaching vehicles while driving.
This is done by the radar gun registering the speed of the officers vehicle while also capturing the the speed of a vehicle heading toward the patrol car while both are in motion.
The radar guns internal computer will accurately compute the speed of an approaching vehicle if the angle is less then 11 degrees.
However at angles greater then 11 degrees, the displayed speed on the officers gun would be inaccurate and who’s favor is anyone’s guess!
How far away can an officer be to shoot me with a radar or laser gun?
Another common question that I’m asked is: How far police radar can travel and why is the sensitivity of a radar detector so important?
Because police radar uses the microwave bands, which are high frequency, the distance traveled is line of sight. However; terrain, buildings, and objects such as signs and electrical lines will effect the range.
Also police radar is directional, meaning if the officer is aiming his radar antenna toward the front of his vehicle and if your approaching from the rear, you may not detect his radar gun until you are very close to his location.
Personally I have been able to accurately target a vehicle with a stationary radar gun in the flat desert at over a mile away.
Would I issue a citation at this distance, hell no!
Because in 1996 there was a landmark ruling in New Jersey Superior Court issued by Judge Staton regarding police lidar.
“laser guns may not target vehicles past 1,000 feet due to the gun’s one millididadian beam divergence of 36″ at that distance. Anything further than 1,000 feet, the laser gun might incorrectly target an adjacent vehicle.“
Now Judge Staton’s ruling only impacted New Jersey law and specifically addressed police lidar.
However someone with this knowledge could reference his ruling in their case, with the result of having their citation dismissed.
Is an FCC license required to operate a police radar gun?
Yes, on December 9, 1996 the FCC issued a requirement that private individuals possess a valid FCC license to operate a police radar gun. Providing an exception to police agencies as long as they already have a communications license.
Does an officer have to be certified to operate a police radar gun?
Federal guidelines and The International Chief of Police Association outline specific guidelines and minimum standards and recommends that officers should be certified in the use and operation of police radar and/or laser. Most states and police agencies have adopted polices and training standards. If you’re cited for speeding, this is one area that you may want to investigate and subpoena the officers training records in regard to his training to confirm that he meets these minimum standards.
How much does the officer need to know about police radar?
All an officer is required to know about police radar is how to set-up, do the calibration tests, operate and be able to interpret the readings from the unit’s audible and visual display. The officer does not need to know the technical aspects on how the police radar gun works.
How often should the police radar gun’s calibration be checked?
The International Chief of Police Association recommends that the officer test the calibration of the device prior to his using the gun and after its use. So typically an officer will check the calibration of the unit at the start of his shift and at the end of his shift.
The International Chief of Police Association and several states also recommend that the police radar gun be calibrated and tested at least once a year by a licensed technician.
All stationary radar guns have one tuning fork and moving radar two tuning forks which are provided by the manufacture of the police radar gun that is used by the officer during this calibration testing process. As these tuning forks can be damaged by simply dropping then onto a hard surface it recommended that they be tested for accuracy during the officers calibration process.
Again, if you’re cited for speeding these records of certification of the police radar gun and tuning fork(s) is something that you will want to subpoena into court. One of our readers did just this in Hartford Connecticut back in 2006, which resulted in the dismissal of hundreds of speeding citations issued by state police.
How accurate is radar?
Police radar is very accurate and manufactures typically certify their units to plus or minus one mile per hour.
Can I jam police radar?
Well technically yes however you will not be able to make your car stealth to a police radar gun and there are NO devices sold in the USA today that will jam or scramble police radar and that includes those devices sold and marketed by Rocky Mountain Radar and/or KAT.
In fact we offer a $50,000 reward to anyone that can show us one of their devices that work as they advertise.
Jamming police radar is a felony and carries a $50,000 fine and five years in prison to anyone that owns, operates, sells, manufactures, distributes or even markets a device as doing so.
Recently the Rocky Mountain Radar Corporation forfeited $20,000 to the FCC for violating this segment of the law and NOT because their unit worked as they advertised.
Can police radar guns interfere with each other?
In rare situations yes they can, but it would be extremely rare to find two police radar guns that operate on the same exact frequency. Also there are safeguards to alert the officer if interference is affecting the radar gun with audible and visual alerts.
Can an officer measure my speed while he is moving?
Yes, moving radar can clock other vehicles speeds while the officer’s vehicle is moving both going in the same direction or even in opposing directions. These radar guns have a second antenna that measures the patrol cars speed while the other antenna tracks the target vehicle. The radar guns internal computer then computes these two droppler signals displaying the target vehicles speed.
What is same direction radar?
Same lane radar is a moving radar gun that also has the feature which can measure vehicles moving in the same direction as the officer.
Does an officer have to show me his radar gun?
No, the prime factor in all traffic stops is your safety and the officer’s safety, thus there is no requirement for the officer to show you his radar gun if you ask.
However if the officer does show you the gun make mental note of the condition of the gun, the make and model. Thus, if you do fight your ticket you may want to do research on the Internet about this unit and also subpoena any information about that gun from the police agency.
Does putting tin foil in my hubcaps affect police radar?
No, in fact the Mythbusters TV series did a full investigation on this myth and other ones such as honking your horn, having a pinwheel on your hood, none of these myths worked.
How about those Stealth Bras or Wax?
There have been several companies on the Internet that have been promoting their stealth bra and wax which they claim will defeat police radar.
Being skeptical we tested all these products back in 2007 and none of them worked as they advertised.
What is Instant On?
An officer can place his radar gun into “standby mode” keeping the transmitter active without broadcasting any signal into the antenna.
This enables the officer to first observe his target then activate his radar gun so he wouldn’t set off a radar detector in the target’s vehicles car if they have one.
A couple good practices to avoid being caught by Instant On include;
1: Not being the “rabbit”! Have someone that is in front of you going slightly faster then you so if there is an officer using Instant On the officer will shoot him first and your detector will activate.
2: Use a radar detector that has extreme range! A detector with extreme range can alert you to the use of Instant on miles away but you will have to pay attention to those short weak bursts that your detector may display.
What is Batching error?
What is refereed to as a batching error would occur on older police radar guns when either a vehicle quickly accelerated or decelerated.
Therefore several of those “other” radar detector review websites recommend that you quickly slam on your brakes if your detector goes off to keep the officer from obtaining an accurate reading on your car.
Well this tactic may have worked in the past, but it doesn’t work today as all of the police radar guns use faster processors, which will account for your deceleration.
What is Scanning error?
Again another error common with older police radar guns which would occur when the officer quickly moved the unit from side to side.
With the new computer processors in today’s radar guns this error is no longer a factor.
What is Panning error?
This error should not be confused with the scanning error as the Panning error typically occurs with dash mounted radar guns when the antenna of the unit is pointed at the processor of the unit.
What happens in this situation is that the device gets feedback, similar to that loud screeching noise you would get if you hold a microphone next to a speaker.
What is shadowing error?
Shadowing error can occur with moving radar when it interprets the speed of another vehicle moving in the same direction as the patrol car as the ground speed.
This error in turn can display a higher speed of the target vehicle.
This error should be obvious to the operator of the police radar gun however this is not always the case.
Case in point one of our subscribers to our free Radar Detector E-Book nicknamed “Da Mail Man” received an unjust citation because of this error in Florida. He fought back by filing a trial by decoration with the courts and won!
You can get “Da Mail Man’s” complete filing by subscribing to our E-Book and downloading it from Chapter Three, “Police Mistakes”.
What is a ghosting error?
Other external devices cause a ghosting error, which at times maybe unknown to the officer when these readings occur, an example maybe the patrol cars heater fan.
Lets say an officer is operating radar in a school zone and the speed is 15 M.P.H. and he has his windshields defroster on and the fan blades are spinning. The police radar gun can incorrectly sense the spinning of the fan blades and display a reading of 25 as the officer is targeting a car that is traveling at only 15.
Other devices that may cause this ghosting error include radio transmitters and high power lines.
Because of advancements in technology, these types of “ghost” readings are rare but they still do happen.
Why didn’t the officer lock my speed on his gun?
One of the most important factors in the training of a police officer in the use and operation of a police radar gun is to establish a visual tracking history of the target vehicle, thus the officer locking onto your speed would circumvent his ability to do this.
However there are several newer radar guns now on the market that will allow an officer to “lock” your speed while displaying your speed on another display.
However this “locking” of your speed is not a requirement.
Can an Officer Visually estimate my speed?
Yes, in fact being able to visually estimate a vehicles speed without the use of a radar gun is the part of several radar and laser certification programs and courts have ruled that a trained officer’s visual estimation of speed is admissible in court.
Why do police radar guns have speakers?
Some readers may recall a television investigative report on police radar back in the 70’s when the reporter clocked a barn speeding.
Because of this report federal standards were instituted to include a speaker in all police radar guns so the officer could monitor the droppler radar tone so they could distinguish a false reading from a true reading.
As the speed of a moving object that is tracked increases, the dropper tone should increase and then as the speed decreases the tone should also decrease.
If you do challenge your ticket in court this maybe a line of questioning that you could pose to the officer by asking if he had the speaker of his radar gun on and if so if displayed speed matched the audio tone output.
Do radar detectors really work?
Good police radar detectors do work; cheap ones are just a waste of money!
If you’re in the market for a radar detector you will want to make sure that the detector’s range is at least six times further then the capture area of a police radar gun.
With some of those cheap detectors that cost around $100 you almost have to be sitting on the officers hood for it to alert.
But typically a detector around the $350 price range will provide you with a four times capture distance of a police radar gun. Higher performance units such as the Passport Max 360 and the Escort Redline will provide you a eight times capture rate distanance!
Does weather affect radar?
Other then the officer getting wet getting out of his car to write you a ticket in the rain, no.
Heavy rain or snow may have a slight impact on the range of the radar gun, but not its accuracy.
However heavy rain or fog will have affect on police lidar enforcement.
What are the steps required for an officer to follow when using his radar gun?
Well the first step of course is to make sure that he has properly checked the calibration of the radar gun prior to issuing any citations and then again prior to ending his watch to make sure that the gun was operating properly.
Then when out on the road the officer should make a visual observation of his target vehicle first and estimate the speed prior to using his radar gun. Once he has established a visual tracking history he then would begin his target acquisition on his target vehicle and confirm visual observations with the audible and digital display on the radar gun.
After this is done all he has to do is activate his lights and pull you over and issue a citation.
I’ve heard that there is an increased risk of cancer with officers that use a radar gun, is this true?
There has been extensive research in this area and basically the risk is very low if non existent. However to minimize this risk officers are now trained not to point the antenna toward their bodies for extended periods.
So now that you understand some of the basics of police radar, I would recommend that you consider downloading my free Radar Detector Buyers Guide E-Book.
In my 48-page E-Book I go into more detail and discuss the devices that are available on the market today along with my recommendations that will help make you a safe and smart driver and avoid those costly speeding tickets.