Antenna Beamwidths of Above-The-Road Radar for Traffic Speed Enforcement in China

Table 1

Theoretical calculation of relative error in various combinations of installation angle and vertical beamwidth.

θ	β
	4^°	6^°	8^°	10^°	12^°	14^°	16^°	18^°
20^°	−1.3%~1.2%	−2.0%~1.8%	−2.8%~2.3%	−3.6%~2.8%	−4.4%~3.3%	−5.2%~3.7%	−6.0%~4.1%	−6.9%~4.5%
22.5^°	−1.5%~1.4%	−2.3%~2.0%	−3.1%~2.6%	−4.0%~3.2%	−4.9%~3.8%	−5.8%~4.3%	−6.7%~4.8%	−7.7%~5.2%
25^°	−1.7%~1.6%	−2.6%~2.3%	−3.5%~3.0%	−4.4%~3.7%	−5.4%~4.3%	−6.4%~4.9%	−7.5%~5.5%	−8.5%~6.1%
30^°	−2.1%~2.0%	−3.0%~2.9%	−4.3%~3.8%	−5.4%~4.7%	−6.6%~5.5%	−7.8%~6.3%	−9.0%~7.1%	−10.3%~7.8%