hehe, good luck using their advice!
And I quote:
The "cosine error" will prove to be very troublesome for the prosecution. Here's why. Let's assume that you determine that the earliest the officer could have seen your car was when you were 260 feet away. At 39 mph your vehicle would be moving at 39 X 1.47 feet or approximately 57 feet per second. Assuming at least one second for the officer to see your vehicle and engage his radar device added to the three seconds he will claim to have clocked you, or four seconds total, during which you will have traveled 228 feet. This puts you only 32 feet from the officers car at the time he "locked in" your speed from his sidestreet hiding spot. The angle of his radar beam to your direction of travel would result in a very serious cosine error. (You would have to be going 150 mph to register a 39-mph reading on a radar device at this type of angle. The officer will have already testified that he estimated your speed at 40 mph, therefore no one will seriously suggest you were actually going 150 mph!).
Sorry, but it doesn't take me 3 seconds to clock someone. My radar unit typically returns a reading in far less than a second. The author is also assuming that the officer would necessarrily have to start clocking you from close range, which is not at all accurate. I write tickets for 1/2 - 3/4 mile out all the time. That distance also reduces the cosine error.
In addition to that, there is nothing saying that the radar reading is a one time only reading. Once activated, it is continous until the operator (officer) shuts it off or returns the unit to standby. This means that the officer can observe the indicated change in your speed as you drive by, even though you actual speed may stay the same. Thus, the officer can testify that the cosine error was observed, and proves that the unit was working as intended. It also proves that your actual speed was higher than your indicated speed, at which point you are assured a conviction.
Just goes to show, don't believe everything you read on the internet.
