hwybear wrote:Have Bookm run around the tarmat with a pie plate strapped to his chest and a aluminum foil helmet?

Oh, that would be a funny PhotoShop pic, anyone?

Hmmm... What's the pay?

Radar Identified wrote: When we're safely clear of the apron/ramp area, during taxi we turn the radar on and point the nose (radar antenna is in the nose cone) at a distant object or set of buildings. If there is a rainshower in the area, even better; we tilt up the antenna and see if the rain shows up on our Multi-Function Display (MFD). Only takes a couple of seconds for the radar sweep to pick it up. We then check that the pattern on the MFD "jives" with what we see outside. So more of a practical test than anything.

So it is not an actual calibrated something or other that makes this test independent.

Police radar testing is very similiar (if I'm understanding correctly). After you have done a self test, you basically rely on an object that you can see at a unknown distance (haven't seen a co-pilot get out a tape and measure to a building)

Police radar testing is beyond just a self test. A test also has to be done in regards to our speedometer. Meaning we have to move, activate the radar and see if the patrol speed matches with the speedometer reading, if 2 antennas are being used, this comparison must be done with both antennas. This comfirms the antennas are transmitting and receiving properly, and produces a speed at a known rate.

I had one case where the internal self-check was showing that it was working, even en route, but the antenna had failed (that was one fun afternoon )... which is why I'm a bit skeptical of internal circuit tests proving that the device is working.

If a self check passed, the officer does the patrol speed comparison and no reading, or intermittent reading, the antenna is not working properly and the unit is taken out of service and sent for repair. Would not be any different with a tuning fork (ding) no reading, antenna not working, unit sent for repair.

hwybear wrote:So it is not an actual calibrated something or other that makes this test independent.

Correct. Independent calibration is done by an avionics technician, but that's required usually every year or so, depending on the unit.

hwybear wrote:After you have done a self test, you basically rely on an object that you can see at a unknown distance (haven't seen a co-pilot get out a tape and measure to a building)

More or less. The shortest range I can use is 10 nautical miles, so a lengthy tape measure would be overdoing it, but just like you have good skills at estimating speeds and distances, we also have to be able to estimate distances - so we have a rough idea of where they should appear. There is another way of checking but it's a bit of overkill. The usual ranges we use are 40 nautical miles (departure/arrival phase) and 80 nautical miles (en route), the primary use, of course, being avoiding significant weather (mostly thunderstorms). If we're close in to an airport for takeoff and final approach we might use the 20 mile range.

hwybear wrote:A test also has to be done in regards to our speedometer. Meaning we have to move, activate the radar and see if the patrol speed matches with the speedometer reading, if 2 antennas are being used, this comparison must be done with both antennas. This comfirms the antennas are transmitting and receiving properly, and produces a speed at a known rate.

Now THAT makes sense. I'll buy that. Thanks for clearing that up.

RI, that would be for the radar units that are moving. Handheld which TC brings up is another story....again I'll have to go look into the manual.

Yes. Poor wording on my part. I should've said "I'll buy that for mobile tests, what about hand-helds?"

Are any tests done for lidar?

Do you guys test on a regular basis?

Like have 2-3 officers drive by in marked cars and test various devices to see if they all get same speed and if that matches the car?

But then what ensures the speed in the police interceptor is also accurate?

The testing procedures for lidar actually ensure the unit is working properly. Tests are more than internal tests.

Unlike any other vehicle, cruiser speedometers are calibrated from purchase date and have this imprinted right on the speedometer.

hwybear wrote:

Unlike any other vehicle, cruiser speedometers are calibrated from purchase date and have this imprinted right on the speedometer.

Still need a check up every so often, with changing of tires etc.........

Aha, we got you RI! You are a pilot! Ever got asked for a pilot license when speeding?

racer wrote:Aha, we got you RI! You are a pilot! Ever got asked for a pilot license when speeding?

Believe it or not... yes. That was one of the most unbelievable moments I've had on the road. Officer was trying to be funny when he stopped me: "Let's see the pilot's license, sir, because you were flying down the road back there." I complied.

I got let go with a warning.

Now that's funny!

Welcome back, proper1! Been a while since we've heard from you.

Why, thankee kindly, RI. I backed off for health reasons: thinking about that damnable 172 was making me sick (as it will anybody who has respect for the rule of law), and reading about it every day was just too much. So why am I here again? I'm not sure... Masochism? The considerable value of so much else on this site? The laughs we sometimes have? Bits of all three, probably.

Any news on how the alleged shakedown man did in his first appearance?