1. Cosine Error

So ive tried searching or tired understanding it...but im still a little conffused. Can someone explain to me how the cosine error works? Thanks!

2. Re: Cosine Error

Originally Posted by xihua
So ive tried searching or tired understanding it...but im still a little conffused. Can someone explain to me how the cosine error works? Thanks!

cosine error

3. hmmm so is it basically wen the radar is far off from the road that the radar that the angle widens out and makes a wrongful estimate? im still not quite strong on it still.

4. Re: Cosine Error

Originally Posted by holein1
Originally Posted by xihua
So ive tried searching or tired understanding it...but im still a little conffused. Can someone explain to me how the cosine error works? Thanks!

cosine error

5. Ya know triangles? Well basically imagine a right angle triangle from your car to the police car. If the radar is directly ahead of you, you are driving on the hypotenuse and thus the speed is 100 %. But if there is an angle, then you are driving on a leg of the triangle, and thus the speed registered on the radar is lower.

Radar speed = (actual speed)cos(angle) if you ignore error on the radar itself.

6. COSINE can have two effects.

1. If officer is shooting stationary radar, and is at a very large angel, for example lets use 45 degrees, then you the driver will have the advantage and the officer will see a lower speed then that what you are actually driving at, for extreme example your doing 75 mph but the radar only shows 65.

2. Now this is where it gets serious, if the officer is shooting MOVING radar, the radar equipment first has to calculate the officers speed! Now if the radar equipment by chance catches an object (such as a exit sign on the side of the road) at a large angle like 45 degrees it will UNDER estimate the officer driving speed so then as it shoots YOU your speed will be grossly OVER estimated!!! If your were doing a legal 65, well now your in for it becasue the officer radar equipment shows that your traveling 75!!!!!!

7. Originally Posted by amoney

2. Now this is where it gets serious, if the officer is shooting MOVING radar, the radar equipment first has to calculate the officers speed! Now if the radar equipment by chance catches an object (such as a exit sign on the side of the road) at a large angle like 45 degrees it will UNDER estimate the officer driving speed so then as it shoots YOU your speed will be grossly OVER estimated!!! If your were doing a legal 65, well now your in for it becasue the officer radar equipment shows that your traveling 75!!!!!!
2. ? you mean the ouch effect and getting mad?

8. Originally Posted by the_Flash083
Originally Posted by amoney

2. Now this is where it gets serious, if the officer is shooting MOVING radar, the radar equipment first has to calculate the officers speed! Now if the radar equipment by chance catches an object (such as a exit sign on the side of the road) at a large angle like 45 degrees it will UNDER estimate the officer driving speed so then as it shoots YOU your speed will be grossly OVER estimated!!! If your were doing a legal 65, well now your in for it becasue the officer radar equipment shows that your traveling 75!!!!!!
2. ? you mean the ouch effect and getting mad?
However, the "PATROL" speed window should be notably off. Any competent and honest officer of the law would disregard any such reading. If you're driving 55 and the radar says you're going 45 and that guy in the opposite direction is doing 97 but taking several minutes to pass ya it should be obvious.

However, don't take that to happen every single time.

9. I thought mobile radar used the beams side lobes to calculate it's speed and not the main beam ?

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