Nov 30

POP Radar

POP is a type of radar specifically designed to defeat radar detectors. It’s a very very short burst of radar (16ms or 67ms) that’s designed to be just long enough to register a vehicle’s speed but too short for most radar detectors to pick up on. Sounds pretty scary, but it has some big problems too and, because of this, it really isn’t in use and it’s generally recommended to turn POP detection off on your radar detector altogether.

Let’s go into some detail now about POP radar, what it is, how it works, how well it works, its problems, legalities, pros and cons of enabling POP detection on your radar detector, and so forth.

POP Overview

So POP is a feature available from some radar guns by the manufacturer MPH. The idea is that the officer can shoot a very brief burst of POP radar to “preview” a vehicle’s speed and if it’s a vehicle that they consider to be a possible speeder, they’ll then switch over and transmit normal radar and continuously track the vehicle long enough to develop a tracking history, confirm the radar gun is indeed clocking the vehicle they think it is, and then issue a speeding ticket as needed.

POP in action

Here’s a few example shots transmitting a burst or two of POP and then switching over to shoot normal I/O (instant on) radar.

Let’s quickly talk about the difference between POP, QT, IO, and CO.

POP is a very brief (generally only 67 ms) burst of radar designed specifically to defeat radar detectors. It’s an automated feature meaning that you enable POP mode and then tell the radar gun to shoot a POP shot. It starts and stops the POP shot on its own.

Quick Trigger (QT) is a similar idea, but it’s done manually where an officer manually tells the radar gun to start transmitting and then stop transmitting. The idea is that he can learn to time it so that he stops transmitting right as the radar gun acquires a speed while also shooting too quickly for a radar detector to alert. This used to be a way to defeat radar detectors, but most modern radar detectors are very fast now and so QT is no longer an issue.

Instant On (I/O) is when the police officer leaves their radar gun in hold (not transmitting) so that no radar detectors up ahead alert and then when they see a vehicle they want to get a speed reading from, they then tell the radar gun to begin transmitting and clock a vehicle ahead. IO is not to be confused with QT. While both are designed to defeat radar detectors, QT is designed to be too quick for radar detectors to alert while IO is designed to not give radar detector users advanced warning.

Constant On (C/O) is the simplest mode of radar. The police officer leaves their radar gun transmitting the whole time, whether they’re stationary or moving, and tracks anyone and everyone within their radar gun’s beam. No fancy tricks. Just constantly on, hence the name constant on.

So as you can see, there’s a variety of tricks they can employ to try and defeat radar detectors. In this post, we’re only addressing POP radar.

Now because POP is so quick, even detectors that have the ability to pick up POP radar sometimes have trouble with it. For example, here’s a test with the Redline trying to detect 67 ms Ka POP from the MPH Bee III. With POP enabled, it catches 8/10 shots. With POP disabled, it picks up 0/10 shots.

POP Speed

So how fast is POP, exactly? Well there’s actually two different speeds for POP. You have 67 ms POP from guns like the Bee III (Ka band) and the Enforcer (K and Ka band), and you have even faster 16 ms POP from the Z25 and Z35 (K band only).

67 ms POP is catchable by quite a few detectors with varying levels of effectiveness. The only modern detector I’ve seen that can reliably pick up 16 ms POP is the Stinger VIP. Here’s a test video that @mrkookm shared demonstrating this.

On a fun note, I found that the ancient Cobra Trapshooter (X and K band only, no filtering) can actually pick up 16 ms POP too! 😀

(The 16 ms POP guns aren’t in use here in the States and are more of a novelty than anything else.)

Problems with POP

Now POP was created as a way to specifically defeat radar detectors. However, the way that MPH did it, they’re pushing the limits of their radar guns in such a way where the speeds that POP mode will register can be inaccurate. Not good if a police officer needs to testify that their equipment is working properly, you know?

Mike V of Valentine Research (the V1 guy) wrote up an awesome article going into the details of why POP mode is sometimes inaccurate. In short, the gunn oscillator (the component inside the antenna that actually produces the radar beam) has to be turned on and off super quickly and if you do it too fast, you don’t give it enough time to settle on a steady frequency. The way a radar gun works, it needs its own frequency to be fixed and the “speed” it measures is the difference between the transmitted and doppler shifted received frequency. The faster a target vehicle is moving, the bigger this difference would be. Speed is basically just a measurement of how much the frequency changes. Now this change is supposed to be entirely the result of a vehicle moving at a different speed than the officer. If the radar gun is changing its own frequency and then thinking that change is due to the movement of a target vehicle, it’s going to register speed of the target incorrectly. Houston, we have a problem… Because of this, you can get speeds displayed on screen that are way higher than what they actually are.

Mike even has a little game you can play to see this happen.

I tested this out myself and found that POP mode is indeed hit or miss. It’s more accurate at slow speeds and close ranges (the manual states it’s most effective with 1/4 mile), but the faster the target and the farther away it is, the less accurate POP becomes.

So you’ve got some accuracy errors.

Additionally, because you are doing just a quick burst of radar, you aren’t taking the time to develop a tracking history, something an officer needs in order to issue a ticket. MPH even says this in the manual:

Information derived during the POP burst is non-evidential and to be used as advisory information only, in much that same manner as fastest mode is. Citations should not be issued based solely on information derived from the POP burst since there is no tracking history developed. If the speed is a violation, the radar must be allowed to enter the continuous transmit mode (by pressing the corresponding antenna button again while the POP speed is still being displayed) so that the tracking history may be developed. There is no case law allowing traffic radar citations to be issued without a tracking history, and MPH will not assist in the prosecution of citations issued without a proper tracking history.

So POP isn’t legal to issue tickets. The proper way to use it is to simply previous speeds, both to get a tracking history and because its speeds can be inaccurate.

Is POP In Use?

So POP has some technical and legal issues. Because of this, it really isn’t used much in practice and so it’s not something that you need to worry about encountering on the road.

Enabling / Disabling POP on your Radar Detector

What if you do happen to run into POP one day? Should you leave POP mode enabled anyways on the off chance that you’ll run into it?

Generally, no. Here’s why.

POP detection is pretty tough. It’s a very short burst of radar so if you enable POP mode, the detector has to constantly pause its normal search for radar and go back to see if POP is present. Because the POP shot is so short, it has to do this a lot and this takes away from searching for normal radar. In Escort products, it inserts a 33.8 POP sweep every 60 ms to ensure it doesn’t miss a 67 ms POP shot. The result is that you’ll wind up reducing the performance of your detector for the radar that you’ll actually see in practice and the trade-off isn’t worth it.

Now you may think that constantly searching for these 33.8 POP shots means that you’re going to improve 33.8 detection because you spend so much time looking for it, but not necessarily. It turns out that with some detectors, such as the way Escort products do it, a POP search is actually independent of normal QT/IO detection. To demonstrate this, you can turn segment 2 off on a Redline (segment 2 covers 33.8 detection) and the detector will no longer alert to 33.8, but it will still alert to 33.8 POP. This tells us that the search for POP radar is running independent of normal 33.8 sweeps.

Scanning for POP enables detection of POP shots only. The detector won’t alert to normal 33.8 if it’s not a POP shot. It can tell the difference. Because of this, enabling POP doesn’t actually help traditional 33.8 detection.

That said, that’s not always the case. The V1 implements its POP search differently. The general idea is the same, but it has the ability to check several frequencies at any point during its sweep, so the POP search isn’t as detrimental to the normal sweep the way it is for other products. You can read about V1’s patent for interleaved POP sweeps for more information.

In any event, performance hits when enabling POP mode aside, you’ll also start to get false POP alerts so not only are you getting reduced performance, you’re getting increased falses… all to catch a type of radar that’s really not in use and isn’t legal to issue tickets.

You can see where I’m going with this and why radar detector manufacturers ship their detectors with POP mode turned off.

You may it see POP detection advertised as a marketing point, another type of radar that the detector can pick up, and something to help fill out long checklist feature lists, but it really doesn’t matter in practice.

How well detectors can pick up 67 ms Ka POP

I like testing POP capabilities on radar detectors. It really doesn’t matter in the real world as I’ve mentioned, but there’s not a ton of good information on it. I’m insatiably curious anyways and since it’s easy enough to test, here’s some POP tests with a few different detectors.

As you can see, many of the nicer products are quite good at detecting POP.

This isn’t the case though with all detectors. For example, the current top of the line Cobra is unable to detect it at all.

The previous gen top of the line (prior to Cobra merging with Escort and incorporating some of their DSP technology) could detect POP, but only with about a 50% success rate.

Rocky Mountain Radar makes a really big deal about detecting POP, but they’re unable to do it at all. Not a big surprise given that they’re known for completely misleading claims such as the ability to scramble police radar and lidar, but that’s another story.

So as you can see, the nicer detectors can detect POP just fine. Lower end ones, this isn’t always the case.

but at the end of the day, it doesn’t matter anyways since you’ll wanna run with POP mode turned off either way.

Knowing this, if you look at any comparison tests like these to see how well a detector can pick up POP, they’re cool to see for purely educational purposes, but they’re not a good way to differentiate between a “good” and a “bad” detector. There’s other tests for that like looking at the detector’s sensitivity and maximum range, its reaction speed to quick trigger, how the various filters work, etc., but POP detection isn’t one of the things to look for.


So yeah, POP is a really fast burst of radar designed specifically to defeat radar detectors. It’s more effective in this regard in its faster 16 ms form than in the slower 67 ms form, but both speeds have some serious technical and legal issues that limit their use, and so it’s not something that you’ll need to worry about in practice.

While many radar detectors have the ability to detect POP radar, enabling this feature will lead to reduced performance and increased false alerts so it’s generally recommended to leave POP detection disabled and not bother scanning for a type of radar that isn’t really in use in the first place.

At the end of the day, just turn it off and don’t worry about it. 🙂

There ya go. That’s POP.

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