This little thread should help educate those that get tickets and wonder how... Besides that they were just speeding...

How do radar guns work?

Radar guns utilize the "Doppler principle" to determine speed.
They transmit radio waves at microwave frequencies, and when these waves strike a moving object, they are reflected back to the radar gun at a slightly different frequency. The gun then "mixes" the reflected signal with the transmitted signal, and ends up with a frequency that represents the difference between the two. Since the difference in frequency is generally a number of hertz or kilohertz, it is in the audible range, hence the term "Doppler tone". The speed of the moving object can be derived by performing a calculation using the frequency of this Doppler tone and the original transmit frequency.


How do laser guns work?

Laser guns do not use the Doppler principle like radar guns do. Instead, they use "time difference of arrival". The laser gun sends out a pulse, and calculates the "time of flight" for the pulse to be reflected back to the laser gun. Since the speed of light is a known value, the distance between the laser gun and it's target can be calculated by the time of flight. The laser gun takes multiple distance measurements, and by comparing the different distance measurements over time, it can determine the speed of the target.

How do radar detectors work?

In a nutshell: Modern radar detectors are superhetrodyne receivers, similar to a scanner. First, they use a microwave horn antenna to receive the radar signal. The radar signal is generally passed on to a first mixer stage, where it is mixed with a first local oscillator to produce an IF. The IF is generally passed on to one or two more mixer and IF stages depending on the design. Finally the signal is detected, and then handled by the processing and control circuitry to produce a visual and audible alert. Radar detectors usually sweep the first LO (and sometimes the 2nd or third too) in order to sweep the different police radar bands for a signal. They will also contain multiple filter and amplifier stages.

Are Radar Detectors Legal?

In the US, Radar detectors are legal for passenger vehicles in 49 states. Radar detectors are illegal in Virginia and Washington DC. Federal Law prohibits the use of radar detectors in all commercial vehicles over 10000 pounds. Radar detector use is also illegal on military bases.

What is the difference between X, K, and Ka band?

X-Band is the least common police radar. It is rarely used anymore except in a couple of states, most notably New Jersey and Ohio. Some small towns might also use it on occasion. X-Band IS frequently used by motion sensors, such as those that automatically open the doors at your local supermarket, so in most cases this is what causes X-band false alerts.

K-Band probably has the most radar units out there on the road. However, K-Band is also used for some motions sensors too. Treat K-Band alerts with caution, until you have identified the source.

Ka-Band radar is the newest band utilized for police radar. Some sources claim that most of the new units sold are Ka. Generally, with the higher end detectors, false alerts on Ka are rare, so every Ka alert should be treated as police radar until you know otherwise.

What is instant-on?

Instant-On is a term used to describe a particular method of operating radar that can be used to defeat radar detectors:

The officer puts the radar gun in "standby" or "hold" mode where it is on and ready, but not transmitting any radar. When he visually identifies a vehicle that he suspects is speeding, he switches the radar unit to "transmit" mode and targets the vehicle to obtain a speed-reading. If he chooses, he can then switch the unit back to "standby" or "hold".

Here are a couple of ways to defend against instant-on:

1. Choose a very sensitive radar detector, so that when traffic ahead is targeted with instant-on, you'll get a warning alert before it is "your turn".

2. Never stand out in a crowd, or you'll be the one he chooses to target. Try to follow behind someone else who is going the same speed as you are, maybe 1/4 mile behind him. That way, if you encounter radar, he'll get hit with instant-on, and you'll get an alert on your detector telling you to slow down.

What is POP Mode?

POP Mode is a feature that was introduced by MPH Industries in their latest radar guns, designed to defeat radar detectors. POP acquires a vehicle's speed by sending out a quick burst of radar. This burst was so short that detectors available at the time of POP's introduction did not alert to it, either due to a sweep rate that was too slow to detect it at all, or due to the short burst being filtered out as a false alert. Fortunately, many radar detector manufacturers have since added POP detection capability to their latest radar detectors.


Radar guns that currently have the POP feature:

MPH BEE 3 = 67ms, K or Ka-Band
MPH Enforcer = 67ms, K or-Ka Band
MPH Z25 = 16ms K-Band
MPH Z35 = 16ms K-Band

Many of the latest detectors can detect 67ms Ka-Band POP reasonably well.

The operator's manual for these guns cautions that "Information derived during the POP burst is non-evidential and to be used for advisory information only...citations should not be issued solely on information derived from the POP burst.



Police Radar Bands (USA)
X-Band => 10.525 GHz +/- 25 MHz
K-Band => 24.150 GHz +/- 100 MHz
Ka-Band => 33.4-36 GHz

Laser Gun Pulse Rates (Cali)

100 pps (pps: pulse per second)
125 pps
200 pps
238 pps
380 pps

Radar Bands / Laser use by Town


Atherton: Ka
Campbell: Ka, Laser
Coalinga: Ka
Corte Madera: KA, Laser
Foster City: Laser
Fresno: K, Ka, Laser
Hayward: Laser and Stalker Radar
Hercules: C/O Ka (updated 08/07/2008)
Highway/CHP: Ka, Laser (LTI guns, PLIII) White Z28 Camaros.
Lodi: Laser (PL III)
Merced: Ka ,Pro Laser III
Merced County CHP: Ka (Instant/Constant), LTI Lidar
Modesto: K, Ka
Pinole: KA
Redwood City: K
Ripon: K, Ka, Lidar
Rodeo: KA
Roseville: Laser (PL III)
San Francisco: KA
San Mateo: Stalker LZ1 (updated 08/22/2008)
San Mateo County Sheriff: Ka (updated 08/01/2008)
San Pablo: Laser
San Rafael: Laser
Sebastopol: Ka
Solano County: Laser
South Lake Tahoe: Laser
Stanislaus County CHP: Ka (Instant/Constant)
Sunnyvale: KA
Yosemite National Park Rangers: K, 35.5 Ka
Folsom: Ka, Laser
Placerville: Ka, Laser
Cupertino: Ka, K

 

Mounting Your Radar Detector

Low windshield mounting

Not as good for radar, More likely to give a laser warning when you are targeted, closer to the aiming points(front plate/lights).


High mounting

Good for detecting laser targeting vehicles ahead, Bad for detecting laser targeting you, since it is mounted further from the aiming point.

 

LIDAR Equipment used in California.

Kustom Prolaser III
Specifications
Speed Range: 5 to 200 mph
Speed Accuracy: +/- 1 mph (+/- 2 kph)
Target Range: 10' to 6000'
Pulse Rate: 200 pps

Will not show a jam code if jamed, Very easy to Jam with most devices.

Stalker LZ-1
Specifications
Speed Range: 1 to 299 mph (1.6 to 480 kph)
Speed Accuracy: + 1 mph, - 2 mph (+2 kph, -3 kph)
Target Range: 5' to 4000' (1.5m to 1200m)
Pulse Rate: 130 pps

Can be jammed and will show a code to user when being jammed.

LTI Ultralyte
Specifications
Speed Range: 0 to 200 mph (0-320 kph)
Speed Accuracy: +/- 1 mph (+/- 2 kph)
Target Range (speed mode): 50' to 2000' (Standard), 50' to 3280' (LR)

Pulse Rates:
Ultralyte 100/200 Standard and Ultralyte 100/200 LR Rev 1 - 100 pps
Ultralyte 100/200 LR Rev 2, - 125 pps

Can also be jammed and will also show a code and sound back to user when being activly jammed.


As you can see the range on this is kinda far.. Most the time you dont see them or its too late. Which is how they catch you. These ranges can go from 5 feet to 6000 feet. Most lock at 2100 feet to 1000 feet away.
They work at these ranges as they do not cone out with distance much like radar.

1025 feet away , 75 mph, Red dot on target vehical

 

In California, Laser Jammers are illegal.
California Vehicle Code, Section 28150

Jamming: Electronic Speed-Measuring Devices

28150. (a) No vehicle shall be equipped with any device that is designed for, or is capable of, jamming, scrambling, neutralizing, disabling, or otherwise interfering with radar, laser, or any other electronic device used by a law enforcement agency to measure the speed of moving objects.

(b) No person shall use, buy, possess, manufacture, sell, or otherwise distribute any device that is designed for jamming, scrambling, neutralizing, disabling, or otherwise interfering with radar, laser, or any other electronic device used by a law enforcement agency to measure the speed of moving objects.

(c) Except as provided in subdivision (d), a violation of subdivision (a) or (b) is an infraction.

(d) When a person possesses four or more devices in violation of subdivision (b), the person is guilty of a misdemeanor.

(e) Notwithstanding any other provision of law, a person who has a valid federal license for operating the devices described in this section may transport one or more of those devices if the license is carried in the vehicle transporting the device at all times when the device is being transported.

Added Sec. 1, Ch. 493, Stats. 1998. Effective January 1, 1999.

 

Punch Through explained.

 

saved

PM me for prices!




so at tonights meet, somebody was talking about laser jammers. can you explain that?

 

good info. the best advice other than not speed is to be behind someone going as fast or faster than you.

 

where was the meet at? And yeah I know a thing or two about them... Not that my car would employ such devices....