When considering the acquisition of traffic enforcement equipment, it's important to consider purchasing a Lidar unit instead of radar. To determine which type of unit would best fit your department's needs, an assessment of the environment as well as the pros and cons of a Lidar unit must be taken into consideration.
Radar uses radio waves to determine the speed of a moving object. It sends out an expanding field of radio waves, and receives back reflected waves from all moving objects that enter the field. It is necessary for the operator to determine which moving object is creating the displayed reading(s).
Similar to radar, Lidar (Light Detection and Ranging) is a remote sensing technology that uses a pulsed infrared electromagnetic beam to determine both the speed and distance of a moving object. It sends out a precise beam, displaying to the operator a “red dot” on the targeted object. It receives back a beam from the targeted object, and the targeted object only. The operator only needs to observe which target the “red dot” is placed on, and read the displayed speed and distance.
Here are a few things to take into consideration before purchasing your traffic enforcement equipment:
When considering anticipated use, it should be determined if the environment of highway safety efforts is conducive to the utilization of a stationary, hand-held unit. Does traffic volume and speed necessitate an ongoing range of readings within a given field (such as traffic on an Interstate), or will it permit individual target acquisition? If the anticipated environment necessitates rapid readings from multiple moving objects, then a radar unit may be preferred over Lidar. As Lidar can only be used in stationary mode, does the environment enable sufficient enforcement efforts from a stationary position to justify the acquisition of a Lidar unit?
On the “Pro” side, the simplicity and accuracy of a Lidar unit eliminates many of the challenges and vulnerabilities found with radar units. After following the standard practice of observing a speeding vehicle and estimating its speed, the operator simply points and shoots, listening for the auditory tone that signals a solid lock on the designated target. It requires identification only of a single target – the one reflecting the red targeting dot, with no analysis or guesswork needed. Once your local traffic court judge has been educated as to the manner and method of a Lidar unit, the “the cop was picking up some other speeder” argument will never again fly in court.
4. Freedom of movement
Most Lidar units are powered by rechargeable batteries contained in the unit, allowing total freedom of movement and positioning. Additionally, several models offer the option of utilizing a battery that plugs into a cigarette lighter for use from a police vehicle.
5. Ability to measure
Another benefit to the Lidar unit is its ability to be utilized as a measuring tool. The unit easily gives precise measurements needed for everything from accident scenes, to polling place boundaries, to firing range distances. The Lidar unit is not without its detriments, though, and the Lidar must be used in stationary mode which renders moving measurements impossible.
Cost is another factor: Lidar units are two to three times as expensive as a hand-held radar unit. Calibration expense also comes into play: the entire unit must be calibrated, contrasted with the minimal cost of calibrating a pair of tuning forks for radar units. The units are typically used with model-specific batteries, and batteries eventually wear out. Battery replacement typically begins around $100 (though some models are now available that use rechargeable AA batteries). The Lidar unit is a pretty sophisticated piece of equipment; once out of warranty, repair is not cheap.
In most cases, departments that use Lidar units swear by them. Challenges to tickets based on alleged misidentification of the speeder are basically nil, resulting in quicker, cleaner convictions. With minimal training and practice, a rookie just out of the academy can be almost as effective in speed enforcement with a Lidar unit as a seasoned veteran.
Do you have any other suggestions for officers purchasing radar? Please leave a comment below or email email@example.com with your feedback.
Chief of Police for the La Crosse (Va.) Police Department Rob Hall contributed to this report.