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Old 06-19-2010, 02:47 PM
FireRanger FireRanger is offline
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Default Re: Radar Gun and GPS question

Quote:
Originally Posted by STL View Post
There was a 6 vehicles including my self. So I am guessing he was behind the other 5 vehicles as we all went through the first signal light.
AH HA! I'm not saying this is what happened, but its possible.

When the radar is in a moving mode, it basically assumes the most significant object it sees is the earth. It registers this speed as the patrol car's speed. At the same time, it gets radar returns from the other vehicles in front of it ("Targets"). Usually you can tell it to lock on the strongest or the fastest target. Strongest is usually the closest. Fastest is obviously the fastest but could be any distance away. Clearly he had it in "Fastest Target" mode since he got you.

Remember how I said it interprets the biggest thing it sees (the earth) as stationary to determine it's own speed? Well guess what happens if it picks up a large vehicles in front of it as the earth instead? It will think it is moving slower than it really is and therefore interpret the target speed as being faster. So if the cruiser is going 30 and you're going 60 and it screws up and thinks the cruiser is only going 10, it will interpret your speed as 80 instead. This is possible however it is a rare occurrence. But given he was in bunched up traffic at a light, i wouldn't completely rule it out.

In addition, in fastest mode it is going to display the fastest target regardless of signal strength. You were far away and there was a bunch of other cars between you and his radar. This can all contribute to an inaccurate reading.
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