Almost got a ticket with my R7

dereileak

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Almost got my first ticket today with my R7, was driving on some back roads out in the country, came up around the corner and decided to speed up I was doing about 75 in a 55. The actual corner was marked as 50 but who does that. Around the corner there is lots of corn and crops so you couldn’t see the cars coming towards you, I got about a half second to a 1 second warning for my R7 that I was picking up KA and I hit the brakes fast as I could, just then an LEO came flying around the corner towards me on the highway and I had a bad feeling that he picked up my speed. I probably was able to slow down to about high 60s at that point. As I kept driving I slowed down to 50 to get my average speed down because I pretty much knew he would be coming for me and after about a minute I see him flying around the corner probably doing around 100 miles an hour to catch up to me and of course I got lit up. He asked me why I thought I was pulled over I told him I have my guess is I was going to fast, he asked me how fast I was going and I said I am not sure, of course. I told him when he asked me what I thought the speed limit was that I thought it was 60 miles an hour ( they recently raised the speed limit to 60 on some county roads, although I knew that wasn’t the case here) he let me know that it was actually 50 around the corner. Luckily my radar detectors mounted very high up so I don’t think he saw it, he was very polite and I was very polite to him. I asked him what speed he got me at and he said he wasn’t sure if he’s going to write me a ticket or not yet, part of me wonders if you actually got a speed for me or if he just thought I was going to fast on the corner. Luckily for me I don’t have any speeding tickets he came back and just give me a warning, thank goodness!!!!

I asked him, so what was the speed you got me at and he said “I can write it on the ticket if you want”, LOL, I told him no that’s OK I’ll just drive the speed limit.

So my question is for some reason my radar detector did not pick them up until the last split second when I saw him almost right as I came across him in the corner, is there such a thing as instant on KA for moving vehicles? or what the heck did I just experience? Roughly was a 90 degree corner but usually I pick them up minimally when they are in range, I expected I would’ve picked him up much further from where I was unless he happened to turn it on right as he saw me, I have to look at my dash cam footage. I believe I got the warning sound very slightly before I saw him.

My question is did he even really get my speed (I’m guessing he did) but I’ll never get to find that out.
 

dudeinnz

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Could be Instant/on or Leo could have been using their rear antenna, so poor detection due to terrain. Hard to say without a video.
Lucky for you!
 

Majbha

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If he really did get your speed, he would straight tell you instead of saying "I can write it on the ticket if you want" bullshit. He had the sense of you speeding, that's all.
 

dereileak

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Could be Instant/on or Leo could have been using their rear antenna, so poor detection due to terrain. Hard to say without a video.
Lucky for you!
So some of them use a rear antenna and get your speed after they pass you to make it harder for people with radar detectors to pick them up?
-- Double Post Merged: --
Here is the video here from my dash cam:

Pretty much didn't pick him up until the truck passed me, at that point you could already see him, it went from no detection, to 100% full on signal strength
 
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fitz4321

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Pretty much didn't pick him up until the truck passed me, at that point you could already see him, it went from no detection, to 100% full on signal strength
That looks like I/O. He probably saw a glimpse of you and Went for the kill. You braked faster then he could get your full speed. All the talk was to get you to admit guilt.

I couldn’t hear any sound on the video.
 

nighthawk

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That looks like I/O. He probably saw a glimpse of you and Went for the kill. You braked faster then he could get your full speed. All the talk was to get you to admit guilt.

I couldn’t hear any sound on the video.
I agree with I/O too. No sound for me either, it would help!
 

dereileak

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That looks like I/O. He probably saw a glimpse of you and Went for the kill. You braked faster then he could get your full speed. All the talk was to get you to admit guilt.

I couldn’t hear any sound on the video.
stupid me, I muted the mic about 2 minutes before this happened :/ wish I hadn't of done that I so I could hear exactly when it alerted, the video doesn't make it look like I was going that fast, but in person I was going about 70-75
 

venom690

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The cop cannot use the speed reading on his radar because of cosine effect.

Basically you have to be going straight into him or away from him to get an accurate reading.

Him asking you to admit is because although he probably visually estimated your speed as speeding the reading on his unit would had shown lower than your actual speed, which means that he knew you were speeding but did not know your actual speed exactly which could be defeated in court easily with a lawyer and youe video camera.

Not admiting to your speed was the right thing to do.

About the warning time, it is possible he had the rear antenna on , added to the turn and terrain he probably got you with the rear antenna meaning you were able to reduce youe speed even more.

All in all he wasted his time chasing after you.


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davGTS

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The cop cannot use the speed reading on his radar because of cosine effect.

Basically you have to be going straight into him or away from him to get an accurate reading.


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So on a curve how many degrees off center before they can get you? Is it the same for on a hill?
 

DrHow

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The cop cannot use the speed reading on his radar because of cosine effect.

Basically you have to be going straight into him or away from him to get an accurate reading.

Him asking you to admit is because although he probably visually estimated your speed as speeding the reading on his unit would had shown lower than your actual speed, which means that he knew you were speeding but did not know your actual speed exactly which could be defeated in court easily with a lawyer and youe video camera.

Not admiting to your speed was the right thing to do.

About the warning time, it is possible he had the rear antenna on , added to the turn and terrain he probably got you with the rear antenna meaning you were able to reduce youe speed even more.

All in all he wasted his time chasing after you.


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^^^ likely what he said.

Based on almost frame by fame.... unless he was holding the remote in his hand, there would be some short time for him to process your speed in his head, decide to react and get radar going. If he was not hyper focused on remote in hand quick trigger, that added a few seconds. Without sound it is hard to tell. Possible he lit you up right as back of pickup was going by you.

From the dash cam, you might have just got in the brakes. The radar has to figure out what is going on. If he had it set to watch both same direction and opposite direction, with fastest target, the radar might have had to think for a second. Because, if his device was portable in the sense not hooked up to the car speedometer the radar also has to figure out his speed by targeting fixed objects. Then process what it sees for vehicles based in the radar setting.

Add to that the angle, you hitting the brakes (while he is moving there still is a slight algorithm to delay reading a heavy braking vehicle with moving I/O because of accuracy issue), radar having to get its own speed, figure out which vehicle to show the speed, the angle, all added up to delayed reading, or no reading at all as he came up to go by you.

If he had his connected to speedometer the radar system knows at all time how fast it is going. The I/O reaction time is even faster.

After a K band test day, we were heading back home playing with my Ka stalker. It has features where if mounted, it is a moving radar system. We were on straight road, lots of reflective fixed targets for it to gather my vehicle speed, many targets to get (opposite, same direction, fastest if that setting was on). I noticed some fraction delay with its audio/trigger and speed coming up. Not much. No one we hammered seem to react.

Each rig will react different. Some of the RDF crew run fixed mounted radar for HAM testing and might be able to add their experience testing moving, I/O on a very rural light fixed target, and conflicting same and opposite direction targets. Plus each brand radar system will react differently how/if it gives a reading in difficult I/O hit. Likely when his reading came up, if it did, the angle and your speed lowering quickly, you were within tolerance of no ticket. Plus, what are your state rules? Are they allowed to guess a speed and it counts in court? Do they have to lock in the speed manually in order to write a ticket? What are their training requirements to get a reading where in court it will always stick based on the law of how to use radar?

Agree with above, keeping quiet with your speed (when he saw and targeted you) in this scenario was good.

Nice video, nice example we can all learn. Or validate the dangers with wide open rural roads, light traffic in front not able to have trigger happy moving I/O cop from giving more warning up up ahead. This also shows the R7 is not Mighty Mouse with a cape. Thank you. Nice post and communication.
 
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venom690

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So on a curve how many degrees off center before they can get you? Is it the same for on a hill?
Click the link i posted on my reply. It explains how the cosine effect works.

On a hill it is the same thing, the greater the angle, the greater the innacuracy of the reading.



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venom690

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^^^ likely what he said.

Based on almost frame by fame.... unless he was holding the remote in his hand, there would be some short time for him to process your speed in his head, decide to react and get radar going. If he was not hyper focused on remote in hand quick trigger, that added a few seconds. Without sound it is hard to tell. Possible he lit you up right as back of pickup was going by you.

From the dash cam, you might have just got in the brakes. The radar has to figure out what is going on. If he had it set to watch both same direction and opposite direction, with fastest target, the radar might have had to think for a second. Because, if his device was portable in the sense not hooked up to the car speedometer the radar also has to figure out his speed by targeting fixed objects. Then process what it sees for vehicles based in the radar setting.

Add to that the angle, you hitting the brakes (while he is moving there still is a slight algorithm to delay reading a heavy braking vehicle with moving I/O because of accuracy issue), radar having to get its own speed, figure out which vehicle to show the speed, the angle, all added up to delayed reading, or no reading at all as he came up to go by you.

If he had his connected to speedometer the radar system knows at all time how fast it is going. The I/O reaction time is even faster.

After a K band test day, we were heading back home playing with my Ka stalker. It has features where if mounted, it is a moving radar system. We were on straight road, lots of reflective fixed targets for it to gather my vehicle speed, many targets to get (opposite, same direction, fastest if that setting was on). I noticed some fraction delay with its audio/trigger and speed coming up. Not much. No one we hammered seem to react.

Each rig will react different. Some of the RDF crew run fixed mounted radar for HAM testing and might be able to add their experience testing moving, I/O on a very rural light fixed target, and conflicting same and opposite direction targets. Plus each brand radar system will react differently how/if it gives a reading in difficult I/O hit. Likely when his reading came up, if it did, the angle and your speed lowering quickly, you were within tolerance of no ticket. Plus, what are your state rules? Are they allowed to guess a speed and it counts in court? Do they have to lock in the speed manually in order to write a ticket? What are their training requirements to get a reading where in court it will always stick based on the law of how to use radar?

Agree with above, keeping quiet with your speed (when he saw and targeted you) in this scenario was good.

Nice video, nice example we can all learn. Or validate the dangers with wide open rural roads, light traffic in front not able to have trigger happy moving I/O cop from giving more warning up up ahead. This also shows the R7 is not Mighty Mouse with a cape. Thank you. Nice post and communication.
The speedometer being connected to the radar unit is only there to tell the radar unit to switch between moving mode and stationary to reduce patrol shadowing.

Most radars will not start working in mobile mode until the patrol car reaches 20 mph.

By law the radar unit has to get the patrol reading by using the signal from reflected objects, it cannot use the speedometer to get the "patrol" speed reading.This is also to ensure the radar unit is calibrated.The officer has to make sure that the patrol reading on the radar unit matches his calibrated patrol car speedometer reading to make sure the radar is calibrated .




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westwind77

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Normally I would say I/O from your description, however after reviewing the video I question that. Can you confirm the 'hood drop' right as the pick up is in frame is when you got the alert? If so, that LEO did not have eyes on you at all and therefor had no reason to use I/O (unless they use it around corners to nab people like this given the shorter reaction time to when someone is spotted). I doubt he was hitting the truck in front as he could just pace him and chances are he saw him behind and was not speeding. That was an interesting encounter, the sound on the video really would have helped.
 

davGTS

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Click the link i posted on my reply. It explains how the cosine effect works.

On a hill it is the same thing, the greater the angle, the greater the innacuracy of the reading.
I had a look at it and the calculator suggests at an "Actual Speed = 70 mph" and "Cosine Angle = 30 Degrees", Measure Speed = 60.6 mph.

So if I read it correctly it appears that when they are targeting you on a curve their speed measurement is actually slower than what you are travelling?

So arguably, if they clock you a little bit over the speed limit on the curve you can't argue the cosine rule, but the LEO could argue you were probably going a little faster.

Although it then says for the changing angle on the curve, the measured speed is "changing too fast for the radar or lidar to measure", but is this actually the case?

I remember 20 years or so being targeted on a curve on a country road and surprised that I received a ticket given the LEO clocked me on the curve.
 
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RRJ

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That looks like I/O. He probably saw a glimpse of you and Went for the kill. You braked faster then he could get your full speed. All the talk was to get you to admit guilt.

I couldn’t hear any sound on the video.
So some of them use a rear antenna and get your speed after they pass you to make it harder for people with radar detectors to pick them up?
-- Double Post Merged: --
Here is the video here from my dash cam:

Pretty much didn't pick him up until the truck passed me, at that point you could already see him, it went from no detection, to 100% full on signal strength
That really looks like instant on to me. Even if you had your sensitivity turned way down, at that range and terrain you should have smelled him as he was coming around the corner. If it went off as that first truck went by, he was already around the corner and ready to zap you.

I prefer to have a rabbit ahead of me, particularly in rural areas. It not fool proof, but often times it can give you an advanced warning that there is a LEO ahead.
 

DrHow

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The speedometer being connected to the radar unit is only there to tell the radar unit to switch between moving mode and stationary to reduce patrol shadowing.

Most radars will not start working in mobile mode until the patrol car reaches 20 mph.

By law the radar unit has to get the patrol reading by using the signal from reflected objects, it cannot use the speedometer to get the "patrol" speed reading.This is also to ensure the radar unit is calibrated.The officer has to make sure that the patrol reading on the radar unit matches his calibrated patrol car speedometer reading to make sure the radar is calibrated .




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In Ohio (who pioneered the speedometer connected systems going on 30 years ago, it was to get the patrol speed and is/was very legal. Same for Indiana. They connect to certified speedometer system. Ford and others offered certified connection as option. It really speed up target acquisition because not needing to find stable fixed target to get fast I/O patrol speed. Many of the “85mph” tree examples come from this in the old days. Back then I/we proved slowing down more than 3.15mph per second when in target range (C/O or I/O) using radar fix for speed, the top two makers would not bring up a speed. Because of too many errors in the system. This was also known problem by others. One of the reasons to defeat this with direct attached speed sensing off the certified speedometer system. Today, the radars are much better. Get that. Still, RF is RF. These radars systems are not 20 million dollar+ each .mil aviation war fighting systems. Because of non consumer volume levels I bet the COGs on the typical dash radar system is 15% of selling price. That covers all the costs for the company and profits.

Also on rural areas like soybean field corners like the video shows, not much to get a fixed target fix. Any wind, adds to the problem if trying to catch field corn waiving around.

Maybe there are some states or federal base requirements to use the side lobe radar on fixed targets. Certainly the tech is better now. Even if Ford offers the cable as option (buddy of mine has P71 Crown Vic, last of the gens) that has the cable) departments are sometimes too cheap to outfit vehicles this way or pay the extra couple hundred for the capability on the car.

In the end, using tracking fixed objects to determine speed will place higher workload on the radar device. In the video above, it likely slowed the acquisition down by some margin. One of several factors.

Not trying to argue here. More background than anything.

Glad that the multiple factors worked in the ops direction to prevent what was a safe and fun Sunday drive, turning into a expensive mess, insurance hassle.
 
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venom690

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In Ohio (who pioneered the speedometer connected systems going on 30 years ago, it was to get the patrol speed and is/was very legal. Same for Indiana. They connect to certified speedometer system. Ford and others offered certified connection as option. It really speed up target acquisition because not needing to find stable fixed target to get fast I/O patrol speed. Many of the “85mph” tree examples come from this in the old days. Back then I/we proved slowing down more than 3.15mph per second when in target range (C/O or I/O) using radar fix for speed, the top two makers would not bring up a speed. Because of too many errors in the system. This was also known problem by others. One of the reasons to defeat this with direct attached speed sensing off the certified speedometer system. Today, the radars are much better. Get that. Still, RF is RF. These radars systems are not 20 million dollar+ each .mil aviation war fighting systems. Because of non consumer volume levels I bet the COGs on the typical dash radar system is 15% of selling price. That covers all the costs for the company and profits.

Also on rural areas like soybean field corners like the video shows, not much to get a fixed target fix. Any wind, adds to the problem if trying to catch field corn waiving around.

Maybe there are some states or federal base requirements to use the side lobe radar on fixed targets. Certainly the tech is better now. Even if Ford offers the cable as option (buddy of mine has P71 Crown Vic, last of the gens) that has the cable) departments are sometimes too cheap to outfit vehicles this way or pay the extra couple hundred for the capability on the car.

In the end, using tracking fixed objects to determine speed will place higher workload on the radar device. In the video above, it likely slowed the acquisition down by some margin. One of several factors.

Not trying to argue here. More background than anything.

Glad that the multiple factors worked in the ops direction to prevent what was a safe and fun Sunday drive, turning into a expensive mess, insurance hassle.
ALL police radars use ground speed to feed into the computer to measure patrol speeds and also target speeds, this is necessary I believe for the computer to be able to better "read" the returning signal of cars it needs to know the returning signal of the cop car, I do not believe this can be done with the reading of the speedometer alone.

Also the radar can pick up speed from the ground itself and it does not need stationary objects that stick out of the ground to do so.The ground itself will return the signal it needs to read speed.

However newer guns do allow for speedometer or "VSS" cables to be installed on the unit for two reasons:

1: it helps it know when it is moving and stopped to automatically switch between stationary and moving mode and to reduce shadowing (what happens when a vehicle is erroneously picked up by the radar unit as ground speed hence possibly making the target speed appear to read faster than it should, this is why it is a requirenment for the officer to watch the "patrol" window to make sure his speed matches that of the radar.

2:It helps the radar unit read the right speed, when the radar unit knows how fast is going thanks to the VSS the radar unit can quickly acquire speed one the patrol car starts moving and to help it pick to correct return signal.

The radar unit will never use VSS to compute vehicle speed and it will read blank if it cannot read a ground speed, rather it will just assist the radar unit to acquire the correct reading for the patrol car.

This is from the stalker dual owners manual:

"VSS OPTIONTraffic Radar Patrol Speed Measurement Moving traffic radar systems normally obtain patrol speed by measuring the speed of the radar return from the moving roadway in front of the vehicle. Patrol speed tracking sometimes suffers from anomalies known as “batching” and “shadowing”. These anomalies occur during moments when the roadway is obstructed from the radar beam by road conditions or other vehicles. The solution is to allow the traffic radar to monitor vehicle tire rotation and to use this information to perform “patrol speed steering.” The simplest way to monitor tire rotation is to attach to the Vehicle Speed Sensor (VSS) signal in the patrol vehicle. The VSS Speedometer SignalAll modern vehicles have a VSS sensor (Vehicle Speed Sensor) attached to the transmission or an axle that generates a speed signal. The speedometer and other electronics in the vehicle use the VSS speed signal. By tapping into this signal, the Stalker Dual DSR can monitor the actual patrol car speed and use the VSS speed information to help the radar pick the correct ground speed. The radar’s patrol car speed is still always measured by radar. The VSS simply helps steer the radar into making the right choice. "

also from the Kustom Golden Eagle 2 :

"
5.0. General Theory

The Eagle II Plus moving radar system transmits a radio frequency on either K-Band, or Ka-Band, in compliance with the Federal Communications Commission (FCC) regulations. A portion of the transmitted signal strikes the surface of the roadway and surrounding terrain and reflects back to the antenna. This returning signal is the "groundspeed" Doppler. From the antenna, it travels to the Digital Signal Processing (DSP) where the signal is translated to the speed of the patrol vehicle (groundspeed) and is displayed in the PATROL window. "

Also and most impotrant quote here:

"
8.3. Groundspeed
True groundspeed of the patrol vehicle is required by all moving traffic radar systems before a target vehicle speed can be accurately computed. If the Eagle II Plus loses correct groundspeed, the operator can recapture groundspeed by quickly activating and then deactivating the HOLD mode. In most instances this tactic will also eliminate a combined speed in the PATROL window.
The Eagle II Plus DSP system will always look for and display groundspeed before displaying any targets. The groundspeed radar signature is unlike any target or interference signal. The DSP can identify this pattern, which is helpful in situations such as shadowing or combined speeds. While this technology will eliminate most of the influences found in moving radar, it is still the responsibility of the operator to complete a tracking history on the target vehicle and verify the patrol speed with the patrol vehicle's speedometer.
Close observation of the patrol vehicle's speed reading is recommended to avoid possible confusion. "




-- Double Post Merged: --
Also some interesting notes about Cosine effect:

First of all for the cosine effect to take place it would have to be more than 10 degrees angle from the radar gun.

On stationary mode the cosine effect will always show the vehicle going slower than he really is however:

In moving mode Cosine effect it is random, it may show the vehicle going faster or slower, there is no telling.Cosine effect in moving mode is a valid concern and can be used to dismiss a ticket, where in stationary mode it won't .
 
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GotWake

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Definitely the cosine effect plus maybe I/O and the terrain. He probably got into his radar too early while he was at a bad angle (for him) and you got your speed down fast enough before he could get an accurate reading.

Either way, RDs are probably the least effective in 2 lane, rolling hills full of radar eating vegetation. Even if that was C/O. That LEO would have been shooting radar out into that corn field before he dropped down in that first curve he was coming into before getting to you. You would have gotten a short alert from /insert whatever RD/. Country roads are just hit or miss with a RD. LEOs are extremely good at just hitting cars with I/O on these roads and the problem is no radar detector is going to pick up the signal more than probably a half mile away in this type of terrain. I've got a place I can setup in front of my house that I can cut my R7 range down to 2200 ft and anything like the max360 down to near 800 ft with C/O 35.5.

What he did was try to get you to admit to speeding. He knew you had evaded him by braking so hard and if he could get you to say how fast you were going, write you a ticket. The only response you should ever give is "I thought I was going the speed limit.".
 

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