GENESIS-VPD™ USER’S MANUAL
26
Rev. 09/04
The following table shows the effect that an
increasing angle has on a displayed speed.
Horizontal angle degrees:
0° 1° 3° 5° 10°
15° 20° 30° 45° 60° 90°
Actual
speed:
Displayed speed:
48 km/h
48 47 47 47 47
45 45 42 34 24 0
64 km/h
64 63 63 63 63
61 60 54 45 32 0
80 km/h
80 79 79 79 79
77 74 69 56 40 0
97 km/h
96 95 95 95 95
92 90 82 50 48 0
113 km/h
112 111 111 111 111
108 105 97 79 56 0
129 km/h
128 127 127 127 127
124 121 111 92 64 0
Table 5.2.1 Actual and displayed speeds at antenna-to-target
angles
Small angles (less than 10°) have little effect on
accuracy. As the angle increases, the displayed
speed decreases. At 90°, the target speed is 0—
grossly incorrect. Cosign Effect will always result
in a target speed being displayed that is less than
the actual speed of the moving motor vehicle,
which will always be advantageous to the motorist.
5.2.2 Fan Interference
Fan interference is the most common form of
interference that you are likely to experience. It
is caused when the radar measures the speed of
the vehicle blower fan. Changing the fan speed
causes a proportional change in the display speed.
To correct this, relocate the radar gun so it does
not display spurious speeds or turn off the fan
motor. Fan interference will result periodically in
spurious speeds being displayed and will be
overidden by the presence of a valid target.
Spurious responses are never accompanied by a
valid TRACKING HISTORY WHICH IS REQUIRED BY
SECTION 6.4 OF THIS MANUAL. Fan interference
will deminish the operational range only; however,
it will not affect the accuracy of speed readings.
