Cop Radar.
#1
Cop Radar.
Recently i got pulled over by a cop who was about 200 ft in front of me going in the same direction.He said he clocked me speeding. Im not here to bash the cop but i am just wondering if he really can clock me while he is driving going the same direction at such a distance or is just saying that to check for my endorsement because he didn't give me a ticket.
#2
How RADAR Works page
The Georgia $peedingTICKETKILLER system does NOT rely on “any” technical defenses for radar, rather legal errors of Georgia law instead. Legal errors of law, breaking the chain of evidence, and or proving the officer did NOT properly test the unit in accordance with Georgia law is the only way to win in Georgia kangaroo traffic kourts.
However, one can never be armed with to much ammunition, (in this case knowledge) when going into battle in a Georgia Kangaroo kourt. Knowing in detail how RADAR works may allay some fears in defending against it, or simply satisfy certain curiosity.
The following is an explanation of Police Radar. It explains Police radar and its operation and theory.
· Doppler Radar
Police radar is a Doppler radar. It measures speed similar to the way astronomers measure the velocity and distance of stars. The radar antenna emits a beam in the radio frequency range. The beam bounces off the target, and then returns to the police radar antenna. The velocity of the target will change the frequency of the radar signal. That change in frequency is interpreted by the radar unit and shown to the officer as the target's speed.
· Radar Case
In order for the officer to make a successful speeding case, he needs to establish the following:
1. Venue (or jurisdiction)
2. Date and time of the offence
3. Roadway on which the offence occurred
4. Posted Speed
5.Identify the vehicle and the operator
6. Tracking History
7.Radar Reading
· Tracking
The most important part of a radar case is a tracking history. The radar unit will display a number, and that's all. It doesn't tell the officer which vehicle it is, or if there's even a vehicle there. The officer has to track the vehicle to make sure that his observations match what the radar is showing him. Otherwise, the officer might stop the wrong vehicle or a common radar error might give an incorrect speed. In some cases, the officer will testify to visually estimating the violator's speed to within 5 miles per hour. The Georgia system has a trial tested KILLER defense for this officers’ visual estimate of your speed (using relevant Georgia case law) that will make him/her look like an absolute idiot on the witness stand.
The radar beam is a cone. It does not pick out individual vehicles. It cannot even pick out individual lanes. The radar shows a speed based on three factors.
- Reflectivity
- Position
- Speed
This isn't as hard as it might sound. Radars are equipped with a speaker which give a tone reflecting the Doppler signal its receiving. If it's a clear high pitched tone, then it's getting a good solid reading from a vehicle. It will give a low raspy tone if it's not getting a clear signal. This happens when there is something in between the radar and the target or when the vehicle is entering or leaving the beam.
Once you have a solid tone, you look at how the traffic is moving. If there is a clump of vehicles that is moving at 65mph then a vehicle overtakes them at a high rate of speed, and the radar shows 85mph, it's easy to figure out who was going that fast. Alternatively, if a group of vehicles is traveling together in a clump, where no one is overtaking or falling behind, all the vehicles in that clump will be at about the same speed.
Some radars have a fastest vehicle button that will display the fastest vehicle in its cone. This is very useful for when there are large targets such as tractor-trailers in between the radar and a fast moving small vehicle.
Modes of Radar
Stationary radar is radar at its simplest. The officer sits on the side of the road, and watches traffic. When he observes a vehicle moving at high speed, he activates the radar.
The radar goes through its basic decision factors (Reflectivity, Position, and Speed) then it displays that speed. The radar will give a tone. If the tone is clear and the displayed speed matches the officer visual observations, the officer can make the stop.
· Moving
Moving radar is very similar stationary radar, but it is looking for two different speeds. The radar looks for the largest object in its field, and it assumes that this is the passing background. Then it looks for the second most significant object that it assumes is the target. The radar actually measures the closing speed or separation speed between the target and the patrol vehicle. The radar's counting unit will then use the following formulas.
Target Speed (TS) = Closing Speed (CS) - Patrol Speed (PS)
or
Target Speed (TS) = Separation Speed (CS) - Patrol Speed (PS)
The radar unit will then display two speeds. It will show the target speed and the patrol speed. The officer must compare the patrol speed displayed on the radar with that displayed on the car's speedometer. This is an essential element of the radar case. The radar speed will be more accurate, but there are certain errors that this will detect. The speeds must be consistent.
· Same Direction
Same direction radar was developed when engineers were examining the shadowing error. Same direction radar uses very different logic than either moving or stationary radar. It also requires more a complicated tracking history.
Basically, it figures out the patrol speed. Then it looks for the bounced reflection off the other vehicle and measures the relative speed between them. This makes things more complicated because the officer must decide to activate the radar, let the radar know if the officer or the target is moving faster.
Radar Errors
· Interference
Police radar uses part of the electromagnetic spectrum. Any number of electromagnetic and physical phenomena can influence them. Air conditioning units in patrol cars can create a reading (generally 30 mph). Some high power lines can also set off radars (generally around either 90 mph or 100 mph).
Officers must have a good tracking history in order to confirm that his observations are matched by the speed displayed by the radar. If an officer is traveling along a road with a 35 mph limit, and sees a vehicle traveling at around 50 mph, and the radar displays 100 mph, he knows that the result is bogus. An officer should know his beat well enough that he's aware of the common sources of interferences.
Some forms of interference, such as the air conditioning units, will disappear when the radar detects an actual moving object. Its decision factors will ignore any signal as weak from the air conditioner unit.
· Cosine Error
Cosine error is when the radar antenna is at an angle to the target. Instead of coming straight towards the antenna, the target is moving across the beam. Some of the speed is lost.
Basically, this means that if an officer is sitting at an angle to the flow of traffic, the speed indicated will always be lower than the actual speed of the target. In stationary mode, it is always to the advantage of the violator.
In moving mode, a cosine error can reduce the computed speed of the patrol vehicle. So when the counting unit computes the target speed with CS-PS=TS, the target speed will be higher than it should be. To counteract this, the officer needs to check his speedometer against patrol speed displayed by the radar. In MOVING mode, it is always to the disadvantage of the violator and something you need to consider if targeted with MOVING radar.
· Masking
Masking is a rarely observed error where the radar antenna is pointed at the counting unit (the part of the radar that shows the speed).
· Shadowing
Shadowing is when an officer is behind another moving object. Usually it will be something large like a tractor-trailer. The radar will interpret the tractor-trailer as the background instead of the actual background. Therefore, when an officer is running moving radar, he has to check the patrol speed showed by the radar unit against his speedometer. If they don't match then he may have a shadowing error.
· Batching
Batching is when an officer is accelerating and activates the radar. Most modern radars have internal error checking that prevents this from being an issue.
· Scanning
Scanning is when you swing a radar antenna across a background. It's possible to get the radar to show a speed this way, but it is hard.
Other Potential Issues with Radar
An officer must be trained to operate Radar in the state of Georgia. It will be an element of the case that the officer will make in court. Asking the officer for this permit on the side of the road is a waste of time. It does not take much to figure out how the radar works, but it does take some training and experience.
· Two Officer Teams
On some occasions, officers will act in teams. One officer will operate the speed detection equipment, and another officer will issue citations. This is particularly common in the state of Georgia.
In order to obtain a conviction, the officer who identifies the violation must be in court to identify the violation. The officer who issues the citation must come to court to identify the driver. The officers must also be able to say how they were to pass the information about the violation between them.
Georgia law (we teach you this in our system) pertinently requires that when an officer makes a traffic case based on information received from another officer, both officers MUST appear in court. In these scenarios, they rarely do, because they know you are ignorant of this and can beat you with just one officer.
· Calibration (this is where most RADAR cases can be killed)
Radars “MUST” be checked for accuracy daily. The results of these tests must be recorded and maintained. Under Georgia law, the officer has to check it at the beginning and end of each shift. The check for accuracy consists of the following:
- A light check. The officer presses a button on the radar, and all the LED lights light up.
- An internal circuit check, which is accomplished by pressing a button on the radar unit.
- Tuning fork check. Tuning forks that are tuned to vibrate at a certain frequency are put in front of the radar antenna. The radar unit will display a certain speed.
#5
· Moving
Moving radar is very similar stationary radar, but it is looking for two different speeds. The radar looks for the largest object in its field, and it assumes that this is the passing background. Then it looks for the second most significant object that it assumes is the target. The radar actually measures the closing speed or separation speed between the target and the patrol vehicle. The radar's counting unit will then use the following formulas.
Target Speed (TS) = Closing Speed (CS) - Patrol Speed (PS)
or
Target Speed (TS) = Separation Speed (CS) - Patrol Speed (PS)
The radar unit will then display two speeds. It will show the target speed and the patrol speed. The officer must compare the patrol speed displayed on the radar with that displayed on the car's speedometer. This is an essential element of the radar case. The radar speed will be more accurate, but there are certain errors that this will detect. The speeds must be consistent.
· Same Direction
Same direction radar was developed when engineers were examining the shadowing error. Same direction radar uses very different logic than either moving or stationary radar. It also requires more a complicated tracking history.
Basically, it figures out the patrol speed. Then it looks for the bounced reflection off the other vehicle and measures the relative speed between them. This makes things more complicated because the officer must decide to activate the radar, let the radar know if the officer or the target is moving faster.
police cars have front and rear radars to check cars in front as well as behind so yes... he could have known how fast you were going...
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