BL> How could you possibly see a red dot at 800 metres?

PQ> It's not a beam, but a target indicator built into the
PQ> electronics/optics. As the system starts getting echoes from
PQ> the target the colour changes through varying hues, till it
PQ> gets a 'solid' return, at which point the operator can lock
PQ> (i.e. freeze) the target picture. The basic technology isn't
PQ> radar in the classic sense, but utilises low-power tight beam
PQ> laser range-finding and doppler (I think) return/computations.
PQ> Which explains the short-ish range of 800-odd meters. 

 What do you mean by "lock the target picture"? There is no
"lock."

 If a car is 1.5m wide, at 800m that's 0.1 degrees and the car in the
next lane is 0.2 degrees away. It is impossible to aim a hand-held
rifle to better than 0.2 degrees, without a proper rest. How can you
"lock" it unless you actually have an image at that instant, or a
servo built into the aiming device? Is therea camera?

 without an actual stored image, all it can do is beep and when the
cop looks all he will see is a range of cars trembling in the optics.
The target could be *anything*.

 The question is not whether the laser technology is accurate... just
*which* car is it timing in traffic at extreme range. The only
difference between the laser and a good rifle at 800m is windage.
Could an average cop *shoot* a car at 800m?

 The answer is no way, Jose.

BL> I imagign that it would be something like shooting a rifle,
BL> where the problem is not the optics, it's the stand.

PQ> Okay. (All of the above, actually... and more.) When was the
PQ> last time you participated at a rifle range, Bob? 

 1965... something. You're not going to tell me that rifles have
improved, are you? We shot 303's in those days, using peep sights and
a rest. I had a mate who was deadly at 600m, but I was lucky to hit
the target at all. Standing, and in the heat fo the moment, I could
miss at 100 metres, and I expect that most cops are the same.

 In any case, the court agrees with me.

Regards,
Bob
 

--- BQWK Alpha 0.5