What is the angle effect caused by the stationary operator during radar measurement?

The angle effect during radar measurement, particularly as it pertains to stationary operators, is predominantly referred to as the cosine effect. This effect arises when the radar beam is not perfectly aligned with the direction of the target vehicle's motion. Instead of the radar measuring the true speed of the vehicle, the reading is influenced by the angle at which the radar signal intersects the path of the target.

When the radar is aimed directly at the target, the speed indicated is accurate. However, when the radar is angled, the speed measurement becomes a function of the cosine of that angle. This means if the target vehicle is moving at an angle relative to the radar, the measured speed will be less than the actual speed of the vehicle. The relationship can be mathematically represented where the measured speed is maximally affected when the angle approaches 90 degrees. Understanding this effect is crucial for operators to accurately interpret radar readings, as such misalignment can lead to significant discrepancies between actual vehicle speeds and those displayed by the radar device.