Lidar Cosine Effect

Here is a copy of the lidar cosine effect from law enforcement training manual. It will show the true speed data with different angles.

http://img139.imageshack.us/img139/7...eed2em4.th.jpg

You can easily calculate the speed using the formula below to create such a chart in excel

true_speed = radar_speed / Cos(angle)

Edit: Corrected typo caught by memtek

I've rescanned the document and is better.

Quote:

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Originally Posted by ahmadr

You can easily calculate the speed using the formula below to create such a chart in excel

true_speed = radar_speed * Cos(angle)

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Nope, I'm sure it was a typo on your behalf. Correct is:

radar_speed = true_speed * Cos(angle)

:)

Oops :D

It appears to be better than radar?

how so u read this and what is the term mean?

It basically means that unless a LEO is standing directly in front of a speeding car (0 degrees), the speed the gun will show will be less than what the car is actually doing.

For example, if the car is doing 70, and the LEO were standing 60 degrees off the side of the road, the gun will read 35 MPH. If he were standing 20 degrees, the gun will read 65.

Quote:

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Originally Posted by ELVATO

If he were standing 20 degrees, the gun will read 56.

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I'm pretty sure this is just a typo error. :D

Quote:

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Originally Posted by Azonehits

Quote:

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Originally Posted by ELVATO

If he were standing 20 degrees, the gun will read 56.

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I'm pretty sure this is just a typo error. :D

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I don't know what you're talking about. :lol:

:oops: We can only wish it read that, huh. :lol: