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Purchasing new radar, lidar,  or even traffic signs can be expensive. And with the way technology keeps expanding exponentially, it can be frustrating to purchase equipment that …


The Stalker Speed Module

When you buy a new patrol vehicle, you expect it to be better than the last one, right? Better gas mileage, better safety ratings, more cupholders….

But what if the manufacturer of your new patrol vehicle takes away something very important that you use every day to do your job?

What if they take away VSS access, so now you can no longer connect your dash-mounted radar system directly to your vehicle’s speed sensing computer?

For many late-model patrol vehicles, this is exactly what happened.

The Problem

Connecting directly to the vehicle’s computer via the VSS cable (either through an OBD-II port or by wiring directly into the cable itself) used to be the only way all dash-mount radar systems were able to calculate the speed of vehicles while you were in motion. When access to this cable was removed, many customers were unable to use their Stalker Radar systems in their new patrol vehicles.

Every police radar company faced this same dilemma. Some companies created a solution that relied on GPS to track patrol vehicle speeds so that their radar’s moving mode readings could maintain accuracy.

But if you have ever used a GPS system in a tunnel, in a dense urban environment, while driving through mountainous areas, or even while in a forest, you know that the GPS’s signal can be easily lost. And while this can be an annoyance while using a map app on your phone, it has the potential to render a GPS-powered radar system unreliable or even unusable in certain locations.

The Solution

Our engineers here at Stalker knew that GPS alone was not enough to solve the problem. That is why we developed a solution that combines the ease of GPS with our proprietary Inertial Navigation Technology. Now we can accurately determine your patrol vehicle’s speed no matter how much steel, concrete, or other interference is between you and a GPS satellite – no VSS connection required.

Meet the Stalker Speed Module

The Stalker Speed Module is a small plug-and-play device that attaches right to the back of any of your current Stalker radar units- and it is so simple that anyone can do it in under two minutes. We have Speed Modules available for all 4 of our dash mount radar systems, including the DSR 2X, the DSR, the DUAL SL, and the Patrol. We offer versions for both internal and external antennas.

Internal GPS Antenna Models

The Internal GPS models are designed for use with counting units that are mounted on the dashboard of the patrol vehicle. The GPS component is housed in the Speed Module, and needs to be placed so it has a clear view of the sky.

External GPS Antenna Models

The External GPS antenna model is used when the counting unit is mounted somewhere other than the dashboard, such as under the seat. Use the included 9’ (2.75 m) long cable to connect the Speed Module to the included external GPS antenna that will be mounted on the dashboard in clear view of the sky


Of course, the Stalker Speed Module also supports the very popular Stalker Moving/Stationary auto-switching features found on many of our radar units.

Stalker Radar’s products are renowned for their longevity. We work hard to keep your Stalker radars on the road, even in the face of rapidly changing vehicle technology and evolving National Highway Traffic Safety.

Click here to connect with your Stalker rep to learn more or to get your Stalker Radars connected to your new patrol vehicles today!

A Brief History of Lidar

The foundational concept of measuring how long it takes light to bounce off an object and then return to the observer and then converting that into a measure of distance, or “Lidar”, was first theorized in 1930 by EH Synge. He used searchlights to study the atmosphere, and then in 1938, his concept was used to start measuring the height of clouds.

The invention of the laser in the late 1950’s was what really started to open the door to utilizing light for measurement. In 1961, Hughes Aircraft Company introduced a system that used pulses of light to track the position of satellites. In the 1970’s, more Lidar advancement was made in aeronautics, including utilizing it to map the surface of the moon. By the 1980’s, it began to be utilized in more commercial and consumer-oriented products, such as crop management, discovering archeological ruins in dense jungles, and even in recreating historical monuments for virtual tours.

Lidar and the Law

In 1989, Lidar was first utilized in law enforcement with the introduction of the first police Lidar gun. Since then, the technology has been refined to produce handheld Lidar units that are small, lightweight, and extremely accurate even at distances of over a mile. Since 2006, around 30% of newly purchased police speed detection devices have been Lidar.

Advantages of Lidar for Law Enforcement?

  • Individualized speed tracking. Because Lidar produces a narrow beam (at 1000’ it tracks a circular area with a diameter of approximately 36”), it can track the speed of a single car, even if there is a lot of traffic.
  • It is fast. Nothing travels faster than the speed of light, so with Lidar, you are able to get speed readings in 0.33 seconds or less.
  • The small beam size of Lidar often allows officers to clock the speed of oncoming vehicles without triggering any Lidar detectors they may have (or setting off any other Lidar detectors in the area).
  • Lidar can’t be jammed. Not only can it sneak past many Lidar detectors, but drivers are also not able to “jam” the Lidar beam. Once the officer targets a vehicle with their Lidar gun, they will get a near-instant result, no matter what evasive measures the driver may be attempting to use.
  • No tuning forks required. Radar units require regular calibration to ensure that they track speeds effectively. Aside from a quick daily system check, Lidar has no other daily upkeep, and very simple twice-yearly system calibrations.


It’s About More Than Just Speed

One of the best aspects of Lidar is that it is able to deliver so much more than simple speed data. Some available features offered in various Lidar guns include:

  • Following Too Close Mode – many police Lidar guns (such as the Stalker RLR) give officers the ability to accurately measure the distance between vehicles. Around 33% of all accidents are rear-end collisions– many of which could be easily prevented if drivers maintained the proper distance between themselves and the vehicle in front of them.
  • School/Construction Zone Mode – All Stalker Lidar guns include the option of a <school/construction zone mode> that allows the officer to program the boundaries of a school or work zone into the device in order to accurately track if drivers are reducing their speeds in the areas of your city where speeding is the most dangerous.
  • Police Lidar guns can be paired cameras and ALPR/ANPR technology to read record photo evidence of drivers and license plates, paired with the location, time, and date of their speed violation. It is much more difficult to argue against a speeding ticket if there is photo evidence!


Interesting Facts:

Unlike radar, which is regulated by the FCC, Lidar is regulated by the Food and Drug Administration in the United States.

It has been anecdotally observed that judges give more credence to Lidar speeding tickets in court than to radar speeding tickets.

Even though lidar technology has been around since the 1960’s, there is still no consensus on exactly how the word should be written- or even about exactly what the acronym stands for. Some places write it as “LIDAR,” others as “LiDAR,” some use “Lidar,” while others follow radar’s lead and simply write “lidar.” Depending on who you ask, Lidar is an acronym for “LIght Detection And Ranging” or “Laser Imaging Detection And Ranging.”


You can check out all of Stalker Radar’s handheld police Lidar guns by clicking here, and you can view our LidarCam II that combines the power of Lidar with the indisputable evidence of photos and video by clicking here.

Radar speed detection capabilities were first developed in 1935 in Great Britain by Sir Robert Watson-Watt and his assistant Arnold Wilkins. They figured out how to use radio waves to detect enemy planes at great distances and also utilized this technology to locate German U-boats. He later helped the United States to expand their radar capabilities in the aftermath of the Pearl Harbor bombing.

Do You Know How Fast You Were Going?

It did not take long for law enforcement agencies to recognize the power of this new radar technology. In 1947, Glastonbury, Connecticut started testing out radar to survey the speed of passing vehicles, debuting the world’s first “speed trap” in February of 1949. Officers would work in pairs, with one officer watching the radar system and collecting visual and printed evidence from passing cars. When the first officer noticed a speeder, he would radio an officer parked a short distance up the road, giving him the offending vehicle’s plate number. The second officer would wait for the car to pass, pull over the driver, and issue them a ticket.

Sizing Up the Problems

There were several issues with this technology that would be solved over the following years. The first was the problem of size. Early radar systems were quite large- starting off weighing hundreds of pounds. As they came into use in war planes, technology was developed that enabled them to be manufactured considerably smaller. Later, they were sized to fit into the trunks of patrol cars, eventually shrinking down to the dash-mounted and hand-held units we see today.

X-Band: Evolution

The second issue was that of frequency or “band.” Initially, police radar operated in the X-band or Ku-band frequencies. These bands required the radar housings to be very long to accommodate the frequencies’ longer wavelengths- so long, in fact, that the antenna had to be mounted on the outside of the patrol vehicle. X-band frequencies are also not able to be used in “direction-sensing” radar, meaning that they are only able to detect differences in speed between the patrol car and the car in question, but aren’t able to determine if that car is moving towards or away from the officer. This can make it difficult for officers to calculate speeds quickly.

Over time, higher-frequency K- and Ka-band radars were introduced. This allowed the antenna to shrink down to something that could be mounted to the dashboard of a patrol car or could fit into a handheld radar gun. But the biggest advantage of these frequencies is that they are directional and have a much higher resolution. Now police radars can have “Fastest” and “Strongest” signal displays, which allow officers to pinpoint speeds of smaller cars and motorcycles even when they are near to larger vehicles that put out a much stronger radar signal.

Going Digital

Changes in radar size were accompanied by changes in the radar’s display. Initially, radar displays were in a dial format, where a needle would point to the speed of the car being observed. While the displayed result was accurate, it would come and go in the blink of an eye- not the most accurate method! In 1969, digital readouts were introduced on the new radar models, making them much easier to read.

Getting In Tune

1969 was also the year that tuning forks started to be widely used to calibrate radars. Prior to this, a radar would be calibrated by having a patrol vehicle driving at a specific speed pass by the radar unit. All speeds measured by the device that day would be calculated relative to this “calibrated” speed. Tuning forks eliminated the inaccuracies and “operator errors” that plagued the “drive-by” method.

Radar Á la Mode

Various “modes” have been developed to make obtaining accurate radar readings much simpler. In 1972, moving mode radar was created. This allowed an officer to calculate traffic speeds while driving. Previously, officers only had the option of stationary mode, meaning their patrol car had to be parked while measuring the speed of passing vehicles. In 1985, same direction radar (aka, “same lane”) radar made it easier to accurately calculate the speed of traffic that was moving in the same direction as the patrol vehicle (while also allowing the officer to easily switch focus to traffic moving towards their vehicle if they desired). In 1993, the IACP allowed manufacturers to add “Fastest” modes to their radars, which allowed the units to display information about the strongest target (usually either the largest or closest vehicle) and the fastest target (which, until the introduction of K- and Ka-band radar, was impossible).

Full Circle

We’d like to conclude with an ironic poem by Sir Robert Watson-Watt, mentioned earlier in this article as the inventor of the radar technology that allowed the British to detect German plans and submarines via radio waves. In 1956, a police officer using a radar gun pulled him over and issued him a speeding ticket. Here were his thoughts on the matter:


“Rough Justice”
by Sir Robert Alexander Watson-Watt

Pity Sir Robert Watson-Watt,
strange target of this radar plot
And thus, with others I can mention,
the victim of his own invention.
His magical all-seeing eye
enabled cloud-bound planes to fly
But now, by some ironic twist
it spots the speeding motorist
and bites, no doubt with legal wit,
the hand that once created it.



Radar Timeline

1935 – Sir Robert Alexander Watson-Watt develop the first radar systems in Great Britain to help detect German planes and U-boats

1949- Glastonbury, Connecticut sets up the first radar speed trap and issues the first radar-derived speeding ticket

1969- The first digital radar with a digital readout was produced

1969- Tuning forks promoted by the NBS for radar calibration

1972- Moving mode radar created

1975- K-band radar introduced

1977- Citizen’s band radio operators in New York figure out that they can detect police radar signals and create the first “speed trap warning system

1985- Same direction (aka, “same lane”) radar introduced

1990- Ka-band radar introduced

1990- Digital Signal Processing (DSP) introduced

1993- Radar with “Fastest” mode approved by IACP and placed on the Conforming Products List (CPL)


About Stalker Radar

Radar and vehicle technology continues to develop, and Stalker Radar is committed to always delivering the most accurate, dependable, and reliable radar products on the market. View our full line of dash-mount and handheld radar products here.

If there were just one thing you had to do to keep your city streets safer, you would have implemented it a long time ago. Unfortunately, it isn’t quite that easy. Increasing public safety is an ongoing series of smaller actions that, together, add up to safer roads for us all.

It can sometimes be difficult to know where to start or what programs to implement to get the most “bang for your buck.” Here are six ideas that you can implement today to start moving the needle.

  1. Element of Surprise.
    When your officers are out on patrol, equip them with police lidar. Speeders caught using lidar were 4x as likely to have a radar detector vs. those caught with radar1 because the narrowness of a lidar beam doesn’t activate radar detectors until its too late for the driver to adjust their speed.And since speeding accounts for over 30% of wrongful death auto accidents each year2, catching the kind of people who are more likely to speed could make a huge impact on the safety of your city! If your department doesn’t yet have lidar, be sure that your officers use police radar with an “instant on” feature so they activate as few radar detectors as possible while on patrol.
  2. Too Close!
    While you are out checking vehicle speeds with your lidar unit, you can also check for tailgating violations. Tailgating causes over 950,000 injuries in the United States each year and is the cause of around 2000 deaths3. The Stalker Lidar RLR comes standard with following-too-close mode, which can accurately calculate the distance between two moving vehicles so you no longer have to guess.
  3. Eliminate Distractions.
    The number one cause of road accidents in the US is distracted driving,4 which has proved to be a tougher problem to solve. People are quick to blame texting and cell phone use, which, while definitely a huge distraction, are not the only things that are pulling drivers’ attention away from the road. Chatting with friends, eating, checking maps for directions, and even ridiculous things like shaving or applying makeup while driving are all activities that can lead to accidents.Does your department do any public outreach to educate and remind your community about the dangers of distracted driving? If not, perhaps consider visiting high schools, community groups, or city events. Setting up a display with two cones set around a football field distance apart (the distance one covers while driving at 55 MPH in just 3.75 seconds) with various hazards can make a huge visual impact and educate drivers about just how much can go wrong during just a little glance at their screens, maps, or fellow passengers.
  4. It’s Raining, It’s Pouring…
    Inform drivers about weather-related road hazards. Did you know that 21% of all vehicle crashes are due to inclement weather5? Most of our LED speed signs can be programmed remotely, allowing you to update speed limits and warning messages as conditions on the ground change. Stalker Radar has also recently introduced a set of flood sensors that can be attached to our PMG signs that automatically trigger a series of messages that change based on the water level on the road.
  5. Immediate Consequences.
    Give immediate feedback to drivers. Radar speed signs– the kind that flash an approaching vehicle’s speed and may also include messages like “slow down”- have been shown over and over to reduce speeds by 5-10%6, and this reduction in speed has been shown to remain consistent even years after the signs are installed7.Nudge theory8, a psychological technique that shows that subtle, gentle influences- such as signs that flash if you are driving too fast and stop flashing when you have reached the desired speed- can be an effective and generally inexpensive way to encourage desired behavior. Drivers get the emotional benefit of feeling that they have chosen to do the right thing, and dangerous behaviors like speeding can be reduced without additional expense and effort on the part of law enforcement.
  6. Variety is the spice of life.
    Certain areas, like those around schools, require consistent speed reminders to maintain the highest levels of safety possible. But sometimes your goal may be to decrease average speeds in your city in general, rather than just in particular spots.This is where mobile radar speed signs like those attached to speed trailers come in handy. Set your sign up in a certain area for a few days to a few weeks, reap the benefits of slower speeds, then move your sign to a different location to influence drivers there. Studies show that speeds continue to be reduced in areas that previously had radar speed signs for days after the signs are removed9.
  7. On the Record.
    Our Lidar, radar speed trailers, and speed signs all easily collect traffic data. Use the RLR Lidar to capture and store up to 3,000 datasets. Plug data from trailers and signs into our Traffic Data Analyst software to generate beautiful, easy-to-read reports. Share his information with your governing organizations such as your city council, your precinct management, and concerned members of your community to gather support for initiatives and projects.
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