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How Radar Works
Traffic radar, which consists of microwaves, travels in
straight lines and is easily reflected by objects such as
cars, trucks, even guardrails and overpasses. Radar
works by directing its microwave beam down the road.
As your vehicle travels into range, the microwave
beam bounces off your car, and the radar antenna
looks for the reflections. Using the Doppler Principle,
the radar equipment then calculates your speed by
comparing the frequency of the reflection of your car
to the original frequency of the beam sent out.
Traffic radar has limitations, the most significant
of these being that it typically can monitor only one
target at a time. If there is more than one vehicle
within range, it is up to the radar operator to decide
which target is producing the strongest reflection.
Since the strength of the reflection is affected by both
the size of the vehicle and its proximity to the
antenna, it is difficult for the radar operator to
determine if the signal is from a sports car nearby or a
semi-truck several hundred feet away.
Technical Details
Radar range also depends on the power of the
radar equipment itself. The strength of the radar unit’s
beam diminishes with distance. The farther the radar
has to travel, the less energy it has for speed detection.
Because intrusion alarms and motion sensors
often operate on the same frequency as X-Band radar,
your Solo S2 will occasionally receive non-police
radar signals. Since these X-Band transmitters are
usually contained inside of a building, or aimed
toward the ground, they will generally produce much
weaker readings than will a true radar encounter. As
you become familiar with the sources of these pseudo
alarms in your daily driving, they will serve as
confirmation that your Solo S2’s radar detection
abilities are fully operational.
How Laser (Lidar) Works
Laser speed detection is actually LIDAR (Light
Detection and Ranging). LIDAR guns project a beam
of invisible infrared light. The signal is a series of very
short infrared light energy pulses, which move, in a
straight line, reflecting off your car and returning to
the gun. LIDAR uses these light pulses to measure the
distance to a vehicle. Speed is then calculated by
measuring how quickly these pulses are reflected
given the known speed of light.
LIDAR (or laser) is a newer technology and is not
as widespread as conventional radar. Therefore, you
may not encounter laser on a daily basis. And, unlike
radar detection, laser detection is not prone to false
alarms. Because LIDAR transmits a much narrower
beam than does radar, it is much more accurate in its
ability to distinguish between targets and is also more
difficult to detect.
AS A RESULT, EVEN THE
BRIEFEST LASER ALERT SHOULD BE TAKEN
SERIOUSLY.
There are limitations to LIDAR equipment. LIDAR
is much more sensitive to weather conditions than
RADAR, and a LIDAR gun's range will be decreased by
anything affecting visibility such as rain, fog, or
smoke. A LIDAR gun cannot operate through glass
and it must be stationary in order to get an accurate
reading. Because LIDAR must have a clear line of
sight and is subject to cosine error (an inaccuracy,
which increases as the angle between the gun and the
vehicle, increases) police typically use LIDAR
equipment parallel to the road or from an overpass.
LIDAR can be used day or night.
