Applied Concepts Inc ACMI005 Manuale Utente

Sport2 Owner’s Manual

ANGLE ERROR

The most common mistake made with all radar guns is trying to clock targets at angles.
All radar guns work on the Doppler principle and need to clock objects moving directly at or away
from the gun. Clocking at an angle with a stationary radar gun results in angle error, and the gun
displays a speed that is LOWER than the actual speed.

Cosine Angle Error Chart

Degrees

True

Speed

Error

0.4%
Error

1.5%
Error

3.4%
Error

13.4%

Error

29.3%

Error

100%

Error

25.0 mph

24.9 mph

24.6 mph

24.1 mph

21.7 mph

17.7 mph

0 mph

50.0 mph

49.8 mph

49.2 mph

48.3 mph

43.3 mph

35.4 mph

0 mph

75.0 mph

74.7 mph

73.9 mph

72.4 mph

65.0 mph

53.0 mph

0 mph

100.0 mph

99.6 mph

98.5 mph

96.6 mph

86.6 mph

70.7 mph

0 mph

125.0 mph

124.5 mph

123.1 mph

120.7 mph

108.3 mph

88.4 mph

0 mph

150.0 mph

149.4 mph

147.7 mph

144.9 mph

129.9 mph

106.1 mph

0 mph

200.0 mph

199.2 mph

197.0 mph

193.2 mph

173.2 mph

141.4 mph

0 mph

250.0 mph

249.0 mph

246.2 mph

241.4 mph

216.5 mph

176.8 mph

0 mph

Radar Gun Placement

To get accurate readings, the radar gun must be placed in the line of travel of the target.
At slight angles, the error is very small, however at larger angles, the error becomes substantial.

Calculating Angle Errors

If you know the angle that you are clocking at, you can calculate the actual speed by taking the
radar reading and dividing by the cosine of the angle.

For example: if you are clocking at 30 degrees, and the gun displays 129.9 mph. Take 129.9 and
divide by the cosine of 30 degrees (0.866) to get a true speed of 150.0 mph.