I am extracting exerpts from your material.I guess I should point out that municipalities and county police departments do not receive one penny from the State from speeding tickets. I will say that I think speeding fines are excessive compared to the fines being levied for assaults , disorderly conduct, and shoplifting. The State generates a lot of money from speeding tickets. With most departments, writing speeding tickets is a low priority as we have more important issues to work on. If you see a cruiser in an area many times over, it is generally because citizens are complaining of the speeding traffic. Quite often the violators are the same people who live in the neighborhood.
1. An audio doppler tone is required for a traffic radar track. Having just the visual display is not sufficient as the unit will display speeds without a good track. If the audio doppler was not on and had a corresponding pitch to the speed reading, a ticket could be dismissed for lack of evidence.
(It may vary from State to State but this is not true. I have yet to see a judge throw out a speeding case because the audio doppler tone was turned down. Most officer will have it turned way down or just barely audible. Because they have to listen to their police radio, the noise from radar units does get annoying. Most officers will depend on visual sighting of a vehicle to determine whether or not it is speeding. Officers use the tone to alert them of a speeder in those cases where they are not actively looking for speeders.
2. For the officer to confirm he has a good radar track, a strong, clear, steady tone is required. If the tone changes in pitch, then the displayed speed reading must also change accordingly. This is something that takes practice but a competent operator can estimate the speed of a tracked vehicle just by the tone. Fortunately, this is not enough to get a conviction.
I have yet to meet a "competent" police officer who plays a guessing game as to the speed of a vehicle based on the audible tone. We really have better things to do. I can easily see why an officer doesn't write a speeding ticket based on audibles. He would be laughed at. We look at the target speed and go by that only for writing a ticket.
3. Shadowing is an aspect that can result in undeserved citations. Large vehicles will return a stronger radar signal than small vehicles. Tractor trailer rigs, with their large, flat forward surfaces send back very strong signals. A car, in front, behind or to the side of a tractor trailer rig can be moving along faster than the truck but will not be detected by a radar unit until it gets well in front of the truck. On the other hand, a speeding truck coming up from behind a slower moving car will cause a strong signal to be returned, overshadowing the carís speed which could be much lower. Even though the car is out front, the truckís larger surface area and speed returns a stronger signal than is reflected from the car. The radar operator has to be aware of all traffic in the immediate vicinity of the targeted vehicle. Sudden shifts or changes in the audio doppler tone indicates the radar unit is processing numerous signals. The return of numerous short, differentiated signals in the audio tone makes the radar readings questionable.
Interesting...but most officers I know whill not write a ticket undeer these circumstances. It isn't worth getting up in the morning after working all night to testify in a questionable speeding case. Remember, officers generally have the audio off. The driver of the small car gets a break.
4. For example, a patrol car is traveling along at 55 m.p.h. but the low doppler shift on the radar unit is reading 25 m.p.h. as a patrol speed because there is a large truck going 30 m.p.h. in front of the patrol car. The back end of the truck is reflecting a strong low doppler shift. The radar unit is reading the closing speed of the patrol car on the truck going in the same direction in front. (55 - 30 = 25). From the opposite direction comes a car, traveling at 60 m.p.h. Since the radar unit "thinks" it is moving over the earth at 25 m.p.h., and is closing on the approaching car at 115 m.p.h., then it shows the speed of the approaching vehicle as 90 m.p.h. (115 - 25 = 90). This is 30 m.p.h. over the actual speed of the target vehicle.
In 22 years, I have yet to see this happen.
5. The only way for the officer to avoid writing an undeserved citation in this situation is to check the radar displayed patrol speed against the patrol carís speedometer. They must match whenever moving mode radar is being used.
I have yet to see an officer write a ticket for this. His/her credibility is on the line. Judges remember........