The Doppler effect only works because the VELOCITY of the Sound/Signal is CONSTANT. So if the sender moves toward the receiver, the only way to fit the same number of oscillations in between is to compress them. And compressing waves means increase the frequency. (This is how my Physics Professor explained it to me, 20 years ago ;-)
I really like your new style of videos of you showing your face and teaching. I feel like you are a very knowledgable professor teaching the class an important lecture! haha. nice work!
Subtract 1 from both sides in Doppler effect formula {fr = fo(v-vo/v-vs) vo is velocity of object, vs is velocity of source, v is velocity of sound, (sign convention = positive when moving in the direction of sound otherwise negative)} to get the formula written on board.
ryker bowen says....I feel like you are a very knowledgable professor teaching the class an important lecture! now is that a compliment or wat?? lol anyways nice job vortex!
He forgot to add the fact that you divide the final answer by 2 because the radar gun originally calculates the distance both ways so it doubles the speed. Halving the result will give you the actual speed of the object. So, in this case, 130 mph divided by 2 is 65 mph.
Will other vehicles between me and the police officer interfere with radar? I was stopped about a month ago and the police officer was approximately 1/2 Mile to 1/4 Mile in front of me. There were two other cars between he and I just as his lights went on
Great explanation, just wanted to say that the graphic at 0:45 is a little confusing. To me, that looks like a car slowing down and so the soundwaves are the wrong way around.
You can jam that by sending the original signal in another direction and spoof it at the same time by sending/repeating the same signal back frequency adjusted based on your current car speed.
Fist of all, your videos are very informative, to the point and well detailed! Keep it up!!! I also have three quick questions, I'd really appreciate it if you could answer them! 1)What is the range of most radar guns in order to clock your speed accurately, in order for someone (me) to get a ticket? 2)Also can the police with a LASER gun clock you while the police vehicle is being driven? ( I know its possible while using radar gun, but not sure about laser) 3)I have the escort redline, is there some sort of a method to understand if the signal is coming from the front or the rear of my vehicle? (the redline doesn't have any arrows as you know, so are there any elimination steps that I can take in order to have some kind of an idea) Thank you for taking the time to answer these burning questions I have loll! Keep up the good work :D
+4shebby I'll do a video on your first question since it gets asked so often. The answer is that it depends wildly. The second one, laser is stationary only. I'll do a video on moving mode radar and it'll make sense why it doesn't work with laser. You can sorta tell direction with an arrow-less RD. You basically just pay attention to the signal strength on the display and the audio rampup and correlate that to what's going on around you in your terrain. It takes more brainpower and analysis, but it's possible.
ok awesome for the quick reply! and as for the third pard question, im guessing if theres a cop behind or in front of you and they turn on their gun, the signal is going to be super strong. Also how long does the radar gun needs in order to give you an accurate reading which the police can ticket you. Once there was a cop behind me and he kept turning his k bank gun on and off20-25 seconds each time. How long do they need to clock you before they are confident that you are speeding or not (5-10 seconds?) thanks
Not a simple answer. It might be best to ask on RDF so you can get answers from a bunch of people and so others can benefit from the discussion too. ;)
2:09 - Question: So are handheld radar detectors more difficult to avoid with a detector since they actually have press the trigger when targeting a vehicle, thereby preventing a detector from receiving the signal?
Can the interior of the police of the car alter the speed . If the officer is on the left side while pointing out of the car on the right side of the car. If the police car is moving towards you can that give an inaccurate speed .
how are you suppose to find out that the change in frequency is 34700006713hz if you don't know the speed the car it travels (i mean the radar gun will show; but is there way to calculate the change in frequency by the speed of the car?)
In case of mounted radars (on a car for example) the change in frequency due to movement of target vehicle; will the reflected waves be more compressed due to the movement of radar device also, will there be more change in frequency, in that case will the velocity displayed be accurate?
thanks, I recently dived into radar and got so many questions to ask. Please help if you could get some of that answered. 1) There is an accuracy for each radar device. Will that changing over various distances? 2) How can Doppler frequency be calculated?
2)What do you mean with that?I think all he did is input 65mph to the equation and found the fr(reflected frequency) that way.You dont really need to know the doppler frequency all you need to know is the change of that frequency.
Very odd question, is there any reason this wouldn’t work as well if we were to point the radar gun at a swimming marine animal that’s breaking the ocean surface?
Hey idk if this question was asked before but if you’re moving in a pack of cars going in a straight line at variable speeds would this change out come of the radar gun reflected signal or would you have to recalibrate the gun every time?
What happens if the target is moving perpendicular to the direction the gun is facing? Will it just read 0? And if so, will there have to be extra calculations taking into account the angle the gun makes with the direction the target is moving?
But how is frequency measured? Especially these high frequencies. We can't just measure the peaks and count them so does this use some sort of a resonance circuit or what exactly goes on?
Not too sure if you mention about the sound of different cars. My car is louder than the usual. Does that mean if 2 cars are traveling, the car with the louder engine sound will be detected? Am referring to station radar detector on the street side.
I know I’m kinda late but how do they adjust for angle? Is this why they subtract some amount from the measurement? Or can you just measure the cars when they drive straight at you?
Alright so it is important to measure straight on otherwise it results in inaccuracy due to cosine error. But the measured speed would be slower than the actual speed which works in your favor (at least if your not the police man). For handheld radar it’s essentially impossible to account for cosine error but I think if a stationary radar always measures the car at the same point on the road they could factor in the angle. Nonetheless the difference is minor and would only please the driver.
No. Radar guns are designed to track multiple vehicles moving in different directions, some bigger and some smaller, some faster and some slower. They have strongest and fastest modes so even a strong signal won't prevent a faster signal from showing up on screen. Normally the classic example is a big slow semi and a small fast sports car. The sports car is faster (weaker signal) but the radar gun can still capture its speed in addition to the stronger return signal of the semi. Jamming and returning a fake signal are two different things. :)
But what about if the radar gun is at a 90 degree. It'll be zero right? So the radar gun has to be parallel or smaller angle than 90 to detect a moving object yes?
Man I love your videos! So educational. I recently purchased a redline and programmed it to your specifications with your tips. I'm located in Missouri and had to turn off my K band because it never stops going off. Should I keep it on and just turn on TSR or does that "cripple" the K band too much so I might as well just keep it off. Thanks in advance for the help.
Oh yeah, TSR is basically a must in most places. You do lose some range and it becomes a little slower, but without TSR the detector can be pretty unusable in populated areas so it's a necessary trade-off. Try out Auto Mode as well to help with the falsing further. Then add lockouts using an Escort Live cable and you'll get some more filtering in the city too. :)
+Vortex Radar thank you. One last question. If I am running my RD in spec mode and k band goes off is there a frequency that when I see it I should know "oh that is most likely a cop and not a blind spot false alert"?
They will also go through fibreglass, but it weakens the signal. Which is why fibreglass cars can be harder to detect. The signal goes through, bounces off the metal parts underneath and then has to go back through. It's why fibreglass hulled boats have radar reflectors on the masts.
+Take It Easy I just took a look at the video and yeah, I think I messed something up. That's kind of embarrassing, haha. I wonder what I did wrong... Time to check this out...
+Take It Easy Ah I see my error. That speed equation is supposed to be divided by two and I copied that equation down wrong. Whoops... My bad. Thanks for double checking my math. I forgot to do that and look what happened, haha :D
Does it have an effect if the radar gun is also in motion? One time I passed a cop (we were going opposite ways on a 2 lane road) and he flipped a U and got behind me and pulled me over and gave me a ticket for speeding when I knew I wasn't speeding anywhere near the amount he said I was cause i had cruise control on. Was this just a lying cop or would *both vehicles doing roughly 50 mph towards each other* effect the result the gun shows?
If a cop is posted on the side of the highway with a radar gun. How are they able to tell which vehicle is speeding? Also, if multiple vehicles are speeding at the same time, how do they determine which one is going faster?
Does the distance between the cop using the radar and the road he used the radar gun on, change the accuracy? Does a cop using radar on a road that has a bend change the accuracy?
Learned a lot from this video thanks! Do cops really use aircraft to monitor daily traffic and speeders? If so would a radar detector pick it up? Cause I read just uses time and how fast the plane/helicopter is going to measure your speed.
So how did you come up with the 6713 number? I understand how you got the difference of the transmission and the reception. But I’m unclear where the 6713 came from. Thanks in advance!
That’s the example # he used as the frequency returning back to the radar gun. Basically the difference between the 34.7 GHz and what was reflected back from the target vehicle.
Good question. Radar is subject to the cosine effect copradar.com/chapts/chapt2/ch2d1.html so it does have to be pretty straight on. A side reading wouldn't work.
Great vid man. When I do the calculations I seem to get 129.8 though. (6713 / 34.7*10^9) * (6.71 * 10^8) = 6713/347 * 6.71 = 129.81. Is there a reason for this?
i dont understand how do they measure the speed of tennis balls or baseballs since they are not metalic materials? can those materials reflect radio waves?
Hi, there is a factor 2 missing in the formula (see en.wikipedia.org/wiki/Radar_speed_gun) Speed = Δf/f0*c (=129,8…mph) should be Speed = 1/2*Δf/f0*c (=64,9…mph)
Yes I did why is why I put correction notes at the top of the video description, hoping people would see it. Sorry about the mistake when preparing the video.
Ottaney Bell There actually is. You can buy a radar that will notify you if anyone is pointing a speed gun at your car, giving you a chance to slow down.
Is it true that if you put tin foil in your empty pockets of your car it reflex’s the radar gun in a different direction and they can’t get a reading off you ?
Not necessary. However, the more angle between your direction and the radar gun the higher the cosine effect error. The higher the cosine effect the lower the speed reading on the radar. For example if an officer is traveling in the lane opposite of you he will get less cosine effect than if he was parked on the opposite shoulder from you. For smaller roads the cosine is negligible, but when the radar is more than 30% angle you begin to see higher cosine effect errors that may result in a few miles per hour loss on the radar reading. Essentially any cosine error is in favor of the driver and not the officer. When you have some time you should look into moving radar; it's a useful tool that i use everyday in my patrol vehicle.
Thanks, but this only works for a zero angle between the direction of travel of the car and the direction aiming the gun. Which is never the case unless the officer is standing in the middle of the road. OK so if you know the angle you can still calculate it, but how does it work for an unknown angle? For example when you're trying to measure the speed of an RC plane flying over your head.
That is why there is a theshold for error for example some countries state that for ex speed limit is 100km/h you will get a ticket if you were driving at least 10 km over speed so for example you were driving at 107 and for any reason the radar registered a 110 (3 km error) you already over 100 but some time you get 109 then no ticket!
The moving target changes the frequency of the original radar signal. Have you ever heard a car drive by and once it passes you the sound changes? It's higher pitched at first and then once it passes you, the pitch drops. That's called doppler shift. The sound waves are compressed when it's coming towards you so you get a higher pitch sound and then they're stretched when the car passes you so you hear a lower pitch sound. A radar gun is looking for this same shift in frequency using radar waves. It then calculates the difference between the frequency it transmitted and the frequency it gets back to determine how fast the target is moving.
+Vortex Radar i understood that frequency increases when the car is moving towards me and decreases when its going away but how does the radar know the exact value of the new frequency ?
You are killing it on the new videos. Great to see your channel evolve like this.
+JDH Thank you! :)
The Doppler effect only works because the VELOCITY of the Sound/Signal is CONSTANT. So if the sender moves toward the receiver, the only way to fit the same number of oscillations in between is to compress them. And compressing waves means increase the frequency.
(This is how my Physics Professor explained it to me, 20 years ago ;-)
Cool
Nice
Jesus man thanks a lot. I have a project in school for the Radar Gun and this explains things so much better than any article. Amazing content man
I really like your new style of videos of you showing your face and teaching. I feel like you are a very knowledgable professor teaching the class an important lecture! haha. nice work!
lol
@@VortexRadar Hi Professor Vortex, can the Uniden R3 work in Malaysia?
Do you have to be direct in front or behind for this to work
Subtract 1 from both sides in Doppler effect formula {fr = fo(v-vo/v-vs) vo is velocity of object, vs is velocity of source, v is velocity of sound, (sign convention = positive when moving in the direction of sound otherwise negative)} to get the formula written on board.
Thanks, man. I was struggling (because I'm a layman) to understand the interaction between the two.
this was perfect! just what i was looking for :) thank you!
Great Explanation. You made it so simple. Thanks man
Great explanation! Very well done!
ryker bowen says....I feel like you are a very knowledgable professor teaching the class an important lecture!
now is that a compliment or wat?? lol
anyways nice job vortex!
Killer video, keep it up!
such a great explanation, nice video man
Perfect, well done! thanks a a lot. This is the best you tube video in my opinion
I think it should be ∆f/f = 2v/c
You are the man when it comes to all things radar/radar detectors! Keep it up.
Who else did the math the exact same way he explain and got ~130 mph?
He forgot to add the fact that you divide the final answer by 2 because the radar gun originally calculates the distance both ways so it doubles the speed. Halving the result will give you the actual speed of the object. So, in this case, 130 mph divided by 2 is 65 mph.
Will other vehicles between me and the police officer interfere with radar? I was stopped about a month ago and the police officer was approximately 1/2 Mile to 1/4 Mile in front of me. There were two other cars between he and I just as his lights went on
Awesome explanation, high quality. Thank you!
Nice video dud, really help me with my study
Great explanation!
Why do they use this equation, i mean is there any explanation why divided by original freqeuency?
Great explanation, just wanted to say that the graphic at 0:45 is a little confusing. To me, that looks like a car slowing down and so the soundwaves are the wrong way around.
Thnx alot love from delhi (india)😇
You can jam that by sending the original signal in another direction and spoof it at the same time by sending/repeating the same signal back frequency adjusted based on your current car speed.
It’s a little more complicated than that (and highly illegal), but yeah that’s the idea.
LOL 😂
beautifully explained my dude. A1 video. thanks
Fist of all, your videos are very informative, to the point and well detailed! Keep it up!!! I also have three quick questions, I'd really appreciate it if you could answer them!
1)What is the range of most radar guns in order to clock your speed accurately, in order for someone (me) to get a ticket?
2)Also can the police with a LASER gun clock you while the police vehicle is being driven? ( I know its possible while using radar gun, but not sure about laser)
3)I have the escort redline, is there some sort of a method to understand if the signal is coming from the front or the rear of my vehicle? (the redline doesn't have any arrows as you know, so are there any elimination steps that I can take in order to have some kind of an idea)
Thank you for taking the time to answer these burning questions I have loll! Keep up the good work :D
+4shebby I'll do a video on your first question since it gets asked so often. The answer is that it depends wildly.
The second one, laser is stationary only. I'll do a video on moving mode radar and it'll make sense why it doesn't work with laser.
You can sorta tell direction with an arrow-less RD. You basically just pay attention to the signal strength on the display and the audio rampup and correlate that to what's going on around you in your terrain. It takes more brainpower and analysis, but it's possible.
ok awesome for the quick reply! and as for the third pard question, im guessing if theres a cop behind or in front of you and they turn on their gun, the signal is going to be super strong. Also how long does the radar gun needs in order to give you an accurate reading which the police can ticket you. Once there was a cop behind me and he kept turning his k bank gun on and off20-25 seconds each time. How long do they need to clock you before they are confident that you are speeding or not (5-10 seconds?) thanks
Not a simple answer. It might be best to ask on RDF so you can get answers from a bunch of people and so others can benefit from the discussion too. ;)
i shall try and do that. Thank you :)
This was a very well made video and explains the science very well
Liked and subbed. Great explanation. Great video.
Welcome aboard!
The original frequency is same all times ?
Excellent explanation!! Thanks
Nice Engineering Explained TH-cam channel Style.
I love your drawing of the car
2:09 - Question: So are handheld radar detectors more difficult to avoid with a detector since they actually have press the trigger when targeting a vehicle, thereby preventing a detector from receiving the signal?
Dashmounts also have a button to start and stop transmitting
Your videos are awesome and you are really nice to look at. :)
thank you for the simple explanation. :-)
What if the car change it’s speed
@@xmenxman686 it will dance!!!🤣🤣🤣🤣
@@xmenxman686 The raider gun will show a new speed
Hey! this actually helped. Thanks man!
Might be a stupid question but would the radar read 0mph if your pointing it perpendicular to the the motion of the vehicle ?
Thanks dear I appreciate this video as I lent the theory ( equation) behind this.
No
Excellent tutorial
Can the interior of the police of the car alter the speed . If the officer is on the left side while pointing out of the car on the right side of the car. If the police car is moving towards you can that give an inaccurate speed .
thank you for your good explanation
So, when does a radar gun actually have you when using the R3 ? When the R3 starts to alert, at full "beeping", or when ?
how are you suppose to find out that the change in frequency is 34700006713hz if you don't know the speed the car it travels (i mean the radar gun will show; but is there way to calculate the change in frequency by the speed of the car?)
+Justin C The radar gun does that all itself under the hood. That change in frequency is what it uses to determine the target speed.
btw how is speed of light 6.71x10^8 ?? isnt it 3x10^8 ?
Since we want to measure vehicle speed in miles per hour, what happens when you convert meters per second to miles per hour? ;)
Vortex Radar ohhhh damn i missed that, thanks
Isn't pitch the frequency of sound waves, not radio waves? Thank you for the clarification in advance.
Yep! It’s an analogy. ;)
In case of mounted radars (on a car for example) the change in frequency due to movement of target vehicle; will the reflected waves be more compressed due to the movement of radar device also, will there be more change in frequency, in that case will the velocity displayed be accurate?
I believe the radar guns compensate for movement of the police vehicle or takes it into account.
Great info. You rock!
thanks, I recently dived into radar and got so many questions to ask. Please help if you could get some of that answered. 1) There is an accuracy for each radar device. Will that changing over various distances? 2) How can Doppler frequency be calculated?
2)What do you mean with that?I think all he did is input 65mph to the equation and found the fr(reflected frequency) that way.You dont really need to know the doppler frequency all you need to know is the change of that frequency.
is it true some radars has dual antennas and could clock the speed of 2 different vehicles?
Yeah some can clock multiple cars like the strongest signal and the fastest signal both.
Very odd question, is there any reason this wouldn’t work as well if we were to point the radar gun at a swimming marine animal that’s breaking the ocean surface?
Could it be used to monitor and give feedback on the speed of a moving swimmer?
Hey idk if this question was asked before but if you’re moving in a pack of cars going in a straight line at variable speeds would this change out come of the radar gun reflected signal or would you have to recalibrate the gun every time?
No need for calibration. Wouldn't be practical
What happens if the target is moving perpendicular to the direction the gun is facing? Will it just read 0? And if so, will there have to be extra calculations taking into account the angle the gun makes with the direction the target is moving?
Yep, 0. Google cosine error.
But how is frequency measured? Especially these high frequencies. We can't just measure the peaks and count them so does this use some sort of a resonance circuit or what exactly goes on?
What will happen if I have two radar sensors, and their views are overlapping?
Not too sure if you mention about the sound of different cars. My car is louder than the usual. Does that mean if 2 cars are traveling, the car with the louder engine sound will be detected? Am referring to station radar detector on the street side.
No, that doesn’t have anything to do with it
I know I’m kinda late but how do they adjust for angle? Is this why they subtract some amount from the measurement? Or can you just measure the cars when they drive straight at you?
Alright so it is important to measure straight on otherwise it results in inaccuracy due to cosine error. But the measured speed would be slower than the actual speed which works in your favor (at least if your not the police man).
For handheld radar it’s essentially impossible to account for cosine error but I think if a stationary radar always measures the car at the same point on the road they could factor in the angle. Nonetheless the difference is minor and would only please the driver.
If I have a radar gun or device at a car that transmit exactly same initial freq at higher strength. Would it jam the other radar gun?
No. Radar guns are designed to track multiple vehicles moving in different directions, some bigger and some smaller, some faster and some slower. They have strongest and fastest modes so even a strong signal won't prevent a faster signal from showing up on screen. Normally the classic example is a big slow semi and a small fast sports car. The sports car is faster (weaker signal) but the radar gun can still capture its speed in addition to the stronger return signal of the semi. Jamming and returning a fake signal are two different things. :)
But what about if the radar gun is at a 90 degree. It'll be zero right? So the radar gun has to be parallel or smaller angle than 90 to detect a moving object yes?
Correct
Do Radar guns take photos? Uk
Is it possible to generate some signal un orther to block the radar?
Man I love your videos! So educational. I recently purchased a redline and programmed it to your specifications with your tips. I'm located in Missouri and had to turn off my K band because it never stops going off. Should I keep it on and just turn on TSR or does that "cripple" the K band too much so I might as well just keep it off. Thanks in advance for the help.
Oh yeah, TSR is basically a must in most places. You do lose some range and it becomes a little slower, but without TSR the detector can be pretty unusable in populated areas so it's a necessary trade-off. Try out Auto Mode as well to help with the falsing further. Then add lockouts using an Escort Live cable and you'll get some more filtering in the city too. :)
+Vortex Radar thank you. One last question. If I am running my RD in spec mode and k band goes off is there a frequency that when I see it I should know "oh that is most likely a cop and not a blind spot false alert"?
+Barry Sanders on K band, not really unfortunately
How to you calculate the reflecting frequency? Thanks
Does wind play role in radar detecting faster speed of vehicle?
No
Hi. Great explanation. Can I ask: Do radar guns work through the windshield of a car?
Yep
They will also go through fibreglass, but it weakens the signal. Which is why fibreglass cars can be harder to detect. The signal goes through, bounces off the metal parts underneath and then has to go back through. It's why fibreglass hulled boats have radar reflectors on the masts.
I was told by a radar cop that the radar must be a straight line, not facing up or down facing the car? Can that give a false number?
Yep, Google cosine error
I have a question: if a radar gun is pointed not directly in front or
Behind but to the side of a vehicle willl the reading be false?
That won’t work. Google cosine error.
@@VortexRadar thanks so much for the responses I’ll look that up
Amazing! Thank u
Have you actually calculated the value? My calculator says it is 130mph, not 65mph.
Sorry, which value? It's been a while since I made the video so I don't remember what calculation you're referring to.
+Take It Easy I just took a look at the video and yeah, I think I messed something up. That's kind of embarrassing, haha. I wonder what I did wrong... Time to check this out...
+Take It Easy Ah I see my error. That speed equation is supposed to be divided by two and I copied that equation down wrong. Whoops... My bad. Thanks for double checking my math. I forgot to do that and look what happened, haha :D
Does it have an effect if the radar gun is also in motion? One time I passed a cop (we were going opposite ways on a 2 lane road) and he flipped a U and got behind me and pulled me over and gave me a ticket for speeding when I knew I wasn't speeding anywhere near the amount he said I was cause i had cruise control on. Was this just a lying cop or would *both vehicles doing roughly 50 mph towards each other* effect the result the gun shows?
Radar guns are designed to work when moving too. th-cam.com/video/FL7yhwK158A/w-d-xo.html
If a cop is posted on the side of the highway with a radar gun. How are they able to tell which vehicle is speeding? Also, if multiple vehicles are speeding at the same time, how do they determine which one is going faster?
you are a good men
Does the distance between the cop using the radar and the road he used the radar gun on, change the accuracy? Does a cop using radar on a road that has a bend change the accuracy?
Distance doesn’t affect accuracy. Angle can somewhat due to cosine error, but that’s always in the driver’s favor.
Learned a lot from this video thanks! Do cops really use aircraft to monitor daily traffic and speeders? If so would a radar detector pick it up? Cause I read just uses time and how fast the plane/helicopter is going to measure your speed.
They do in some places, yeah. A radar detector won't help.
So how did you come up with the 6713 number? I understand how you got the difference of the transmission and the reception. But I’m unclear where the 6713 came from. Thanks in advance!
That’s the example # he used as the frequency returning back to the radar gun. Basically the difference between the 34.7 GHz and what was reflected back from the target vehicle.
Does the radar need to be directly behind or in front of the moving object to determine an accurate speed? Or could you radar something from its sides
Good question. Radar is subject to the cosine effect copradar.com/chapts/chapt2/ch2d1.html so it does have to be pretty straight on. A side reading wouldn't work.
Vortex Radar thank you!
Great vid man. When I do the calculations I seem to get 129.8 though. (6713 / 34.7*10^9) * (6.71 * 10^8) = 6713/347 * 6.71 = 129.81. Is there a reason for this?
I mentioned in the video description that I forgot to divide by 2 at one spot.
if you watch an aircraft at cpa then time the seconds until the sound of it gets to the very same place you can guess its distance from you.
Excellent explanation my friend. My question is what if you are moving and the police is also moving, is it possible to get an accurate speed?
Yep! Here’s how that works: th-cam.com/video/FL7yhwK158A/w-d-xo.html
So if a police officer is going 50mph, and the car ahead is going 80mph, would the radar read 30mph? How do they work while on the move?
Here ya go: th-cam.com/video/FL7yhwK158A/w-d-xo.html
Hi... video is very useful. What if the policemen moved his hand while he is activating the device? Can device give a wrong result?
Why would it?
@@VortexRadar when the policeman holding the speed camera, there is a possibility of shaking his hand. Will that effect to the results?
Again, why would it? These are designed to be used handheld by humans, not just on a tripod, so some handshake is normal.
Point at target and pull the trigger. Simple. Don’t shake it like maracas 😄, but handholding is otherwise fine.
@@VortexRadar true. My question was, if there is a hand movement, the results shows in the device can be wrong. Yes or No?
do the radar unit has a volum setting or makes click sound? how do it al
Haha yep, it does
wait so are u suppose to divide the final speed you got by two? im not clear on when the division by two was suppose to occur.
+Mahdee please see the video description :)
i dont understand how do they measure the speed of tennis balls or baseballs since they are not metalic materials? can those materials reflect radio waves?
+tirips etihw Solid objects reflect radio waves, correct
What will happen if you point two guns against each other
I am thinking about tiggering a gun whenever i receive a signal in the radar detector
The two guns won't interact in any way whatsoever. I take it you're wanting to jam the other radar gun? It doesn't work.
Hello, what if another car crosses in between the radar gun and my car, will it give an inaccurate reading ?
+Carlos Gomez Nope, it’ll simply show the other car’s speed.
well explained.weldone
if radar gun is also on moving opposite vehicle will that speed be accurate because if car towards coming to radar gun will be doubled i guess
Yes. They can do moving mode just fine. Opposite lane monitoring is easier for radar guns than same lane monitoring.
Seems like half of the math is missing. How do you get from 6,713 cycles per second to 65 mph?
Hi, there is a factor 2 missing in the formula (see en.wikipedia.org/wiki/Radar_speed_gun)
Speed = Δf/f0*c (=129,8…mph) should be Speed = 1/2*Δf/f0*c (=64,9…mph)
Yes I did why is why I put correction notes at the top of the video description, hoping people would see it. Sorry about the mistake when preparing the video.
What if you put the car into neutral before the speed gun hits the car? What happens then? Does it still calculate your speed ?
Of course. Your car is still reflecting the signal just the same, no matter what your transmission is doing.
Ottaney Bell Well obviously, you’re still moving. You would have to slam on your brakes & probably cause an accident lol.
Thanks. So in essence there isn't an actual way to beat the speed gun at recording your speed then
Ottaney Bell There actually is. You can buy a radar that will notify you if anyone is pointing a speed gun at your car, giving you a chance to slow down.
Can anyone tell me how they shoot me behind them going the same direction how accuracy
thanks for explanation
Is it true that if you put tin foil in your empty pockets of your car it reflex’s the radar gun in a different direction and they can’t get a reading off you ?
Very helpful.
What if the car isn't speeding but it just accelerated really fast at one point. Will it give a false reading?
What do you mean? It displays the current speed, not the speed you did in the past.
Does the car have to be coming directly at you
or away, yes
Not necessary. However, the more angle between your direction and the radar gun the higher the cosine effect error. The higher the cosine effect the lower the speed reading on the radar. For example if an officer is traveling in the lane opposite of you he will get less cosine effect than if he was parked on the opposite shoulder from you. For smaller roads the cosine is negligible, but when the radar is more than 30% angle you begin to see higher cosine effect errors that may result in a few miles per hour loss on the radar reading. Essentially any cosine error is in favor of the driver and not the officer. When you have some time you should look into moving radar; it's a useful tool that i use everyday in my patrol vehicle.
Can it read two car speed at the same time
Thanks, but this only works for a zero angle between the direction of travel of the car and the direction aiming the gun. Which is never the case unless the officer is standing in the middle of the road. OK so if you know the angle you can still calculate it, but how does it work for an unknown angle? For example when you're trying to measure the speed of an RC plane flying over your head.
+Elias Labordus Cosine error isn’t a huge factor unless the officer is at a sharp angle. Run the numbers and you’ll see.
That is why there is a theshold for error for example some countries state that for ex speed limit is 100km/h you will get a ticket if you were driving at least 10 km over speed so for example you were driving at 107 and for any reason the radar registered a 110 (3 km error) you already over 100 but some time you get 109 then no ticket!
Someone asked how does the radar find out the changed frequency but i didn't understand what you replied
The moving target changes the frequency of the original radar signal. Have you ever heard a car drive by and once it passes you the sound changes? It's higher pitched at first and then once it passes you, the pitch drops. That's called doppler shift. The sound waves are compressed when it's coming towards you so you get a higher pitch sound and then they're stretched when the car passes you so you hear a lower pitch sound. A radar gun is looking for this same shift in frequency using radar waves. It then calculates the difference between the frequency it transmitted and the frequency it gets back to determine how fast the target is moving.
+Vortex Radar i understood that frequency increases when the car is moving towards me and decreases when its going away but how does the radar know the exact value of the new frequency ?
its back to school for me cause you totally screwed me up