A License Plate Recognition and Speed Detection System - Index of

100 MHz wide or 200 MHz wide. Since the allocated operating frequency spans a 2600 MHz
range, a radar gun with a 100MHz channel width will have 26 different channels for its operation
resulting in less interference with the system.
The last of the “radar” type systems is the LIDAR or LADAR. The acronym stands for
LIght Detection And Ranging or Laser Detection And Ranging, and they were developed in the
1990’s. They use Class 1 (eye-safe) � pulsed Infra-red (IR) laser diodes at frequencies at the upper
end of the IR spectrum and produce very narrow beams. This is an important attribute when
trying to measure vehicle speeds in congested areas. These units are harder to operate compared
to X and K band radar units. They need to be pointed directly at the moving vehicle using a
crosshair sight. Thus, the operating officer needs to be stationary when using a LIDAR, whereas
X and K band radars can be used in a moving police vehicle. In either case, the officer operating
the radar unit must be trained and certified in their operation.
Photo radars (figure 53) and Red Light Cameras (figure 54) are two types of automated
traffic enforcement devices that are used in various parts of the United States.
Fig. 53 Photo Radar Fig. 54 Red Light Camera
� The FDA’ Center for Devices and Radiological Health regulates the manufacture and sale of laser devices in the
United States. Class1 lasers are defined by the American National Standards Institute.
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