User's Manual

49
Velocity
Vector
Angle
Radar
interference signal, causing the display speed to change
suddenly to the vehicle’s speed.
• The Doppler tone is corrupted with noise.
• Speeds are irregular and do not provide valid tracking history.
• Erroneous speeds appear to track with the engine speeds.
8.2.1 Angular Interference (Cosine Effect)
When operating in the Stationary Mode, the cosine effect causes
the radar unit to display a speed, which is lower than the actual
vehicle speed. This condition exists when the target vehicle’s path
is not parallel to the antenna, including conditions such as the
vehicle traveling on a curve or a hill.
As the angle between the beam of the antenna and the target
vehicle increases, the displayed speed decreases. Ideally, an angle
of zero (0) degrees is preferable, because the displayed speed is the
actual target vehicle speed. However, in all uses of police radar, the
radar device is always at a slight angle to the target vehicle to avoid
collisions.
Figure 8.2.1a
An angle between the antenna and the target vehicle causes the cosine effect.
G3™ User & Installation Manual