How do automotive (FMCW) RADARs measure velocity?

[@benedekt.5909]

I took me almost 3 years to rediscover fast and slow time principle and the reason for the vertical fft, instead of blindly reprogramming the relevant literature magic in my implementation. This video is perfect for understanding this complex concept, thanks!

[@MarshallBrunerRF]

@@benedekt.5909 thanks so much! I’m really happy that you found the video to be useful. Hopefully the notebook helps with that too.

[@JoshuaZitoJZ]

This video is really impressive. The level of quality in this video blows away university lectures and you made this so easy to understand. I can imagine sitting in class and not understanding anything the professor said but this is completely the opposite. Great work and keep it up!

[@MarshallBrunerRF]

That means so much! So glad you found it useful!

[@Syndesi]

Your way of explaining these complicated topics in an easy to follow manner is really impressive, especially when combined with all the custom animated visualizations, real life examples and demo code to play with. I'm really blown away by your work, and I am looking forward to more episodes :D

[@MarshallBrunerRF]

@@Syndesi wow!! Thank you so much! I’m really happy that you’ve gotten some value from it 😊

[@SamAlton]

I can't believe the quality of these videos - your presentation is top notch. You're the 3blue1brown of RF systems. My role at my work is more related to analog signals, but I've always had a fascination and appreciation for RF. These videos definitely scratch that itch for me. Looking forward to more!

[@MarshallBrunerRF]

Thanks so much! I have a huge appreciation for analog design as well. So many cool fields in EE :)

[@mcintoda9]

This video was more challenging to follow, but I appreciate the practical chip level example

[@MarshallBrunerRF]

Anything you think would have made it more approachable? It's definitely a hard concept, so I'd love to know if you have any suggestions for explaining it better

[@LeonardoPJ]

Excellent video. You mentioned the radar from Texas Instruments; I am using the IClegend ones (S3KM111L and S5KM312CL). They also perform these conversion processes. In the paper "On Fundamental Operating Principles and Range-Doppler" by Milovanović, the 2D-FFT is well described.

[@MarshallBrunerRF]

Thanks for the reading recommendation! Just looked it up. Yeah there's many options but I had previously looked into the TI one I showcased, so I chose to go with that. Thanks for watching :)

[@LeonardoPJ]

@@MarshallBrunerRF Did you work only with this hardware?

[@MarshallBrunerRF]

@@LeonardoPJ no most of my work on FMCW systems has been on analog devices phaser radar

[@polares8187]

This is freaking amazing. Also you are beyond amazing for providing the links to the books. Great channel

[@MarshallBrunerRF]

Thanks so much! Hopefully you find some use in the resources

[@anton33779]

​@@MarshallBrunerRF does 14:51 mean that you can just screw over a fmcw Radar if you have 100 drones going the exact same speed? As always an amazing video, I had to reply here because KZbin doesn't show me the comment bar

[@nr.bln.]

I know this might be repeating most of the other comments here but I really appreciate your work and your way of presenting these complex topics in such an understandable way without dumbing them down to the point of being superficial. You are proving such a huge amount of value in terms of understanding and I wish you the best 🫶

[@MarshallBrunerRF]

Woah thanks so much!! I'm so glad to hear people are getting value out of them. Hopefully the value continues beyond the videos with the resources and python notebooks. Thanks again - it means a lot :)

[@electrowizard2000]

Awesome video, you did a great job motivating each improvement and let me feel like I was discovering it for myself.

[@MarshallBrunerRF]

Thank you! That was my goal :)

[@notravstar]

Good videos, I'm really enjoying them and learning a lot. Keep it up!

[@MarshallBrunerRF]

Took a break from working on the next video to respond to comments - will definitely keep them coming :) Thanks for watching!

[@xavierdemers-bouchard2747]

God I love your videos. Always the highlight of my day. So clear. AND study material! Good lord.

[@MarshallBrunerRF]

So happy you enjoyed it!

[@MarshallBrunerRF]

Try out the challenge if you get time!

[@_ifly]

thank you so much for this amazing explanation waiting for more about FMCW such as ( Range, Angle, Velocity) extraction and also and noise removal. also if you could explain about vital sign

[@MarshallBrunerRF]

Thanks for watching! Yeah angle of arrival estimation is super interesting as well and I would love to cover it! For noise removal, I will definitely cover various clutter suppression techniques, but for now I have a video on CFAR that covers target detection if you're interested.

[@cookingmaster6874]

Keep up the good work!

[@yannikmuller2195]

Sometimes you just find a gem on KZbin

[@MarshallBrunerRF]

Thanks so much for watching!

[@nadavgvili9684]

Great job , subbed

[@MarshallBrunerRF]

So glad you liked it!

[@Avriox]

Amazing stuff!

[@MarshallBrunerRF]

Thanks!

[@mass1s]

What if the target velocity is high enough that the phase of the return changes more than 2 pi radians between chirps? The target would show up with the wrong velocity due to aliasing. I presume long range radars with low chirp rates use a different method?

[@MarshallBrunerRF]

Yeah so that's part of your system design and estimating what your environment will include. For this I chose 24 m/s for the max velocity but for many systems you might want to choose higher than that. You can definitely get aliasing, same as you can with range targets being above your sampling frequency.

[@amitlanis3104]

Great video!!! (Btw this comment is from before I saw the video)

[@MarshallBrunerRF]

LOL hopefully when you finish the video you stick by it being a great video :)

[@kamsibryan2974]

What will be the formula to Calculate velocity for a stationary object

[@MarshallBrunerRF]

You can apply both of these same concepts with a 0 velocity target - the output would just be a zero. Try plugging in a 0 velocity target into the included python notebook and see what it outputs. Thanks for watching!

[@marotoby]

Yeah new vid!

[@MarshallBrunerRF]

Thanks for watching!

[@Marcin648]

Great explained! I wasn't far off with the idea of ​​checking the rate of change of the target's frequency, but 2D FFT is much better! Any cheaper solution for hardware then ADALM-PHASER? As I guess my half-duplex HackRF is not sufficient for radars. :)

[@MarshallBrunerRF]

Yeah there's some awesome chips from TI that have eval boards you can pick up for a little over $100 last time I checked. Thanks for watching!

[@anantmishra-h3m]

How does ground penetrating radar work

[@MarshallBrunerRF]

Definitely a topic for a later video. I will have to do more research on that as I haven't directly worked on it. Thanks for the suggestion!

[@NaifAlqahtani]

Again awesome video but the titles man. They gotta change 😂❤

[@MarshallBrunerRF]

What don't you like? What would you have named this video? Thanks for watching!

[@NaifAlqahtani]

I dont know what these letters are for. Dont use them.

[@MarshallBrunerRF]

@@NaifAlqahtani what are you talking about?

[@NaifAlqahtani]

@@MarshallBrunerRF before watching the video, FMCW makes no sense to me at all and would not make me want to click at all. Look at how 3b1b titles his videos. Its never technical words unless absolutely necessary.

[@SamAlton]

​​@@MarshallBrunerRF I think it's a balance between accuracy and accessibility, and it depends on the intended audience of the video. The layperson searching on youtube "how does radar know how fast a thing is moving" isn't gonna know what FMCW stands for (I certainly didn't before watching your videos), and that might turn them away from clicking on it. But maybe the layperson isn't the intended audience for this video. It's extremely well made and communicated, but it's also 17 minutes and has a lot of advanced concepts. At the same time, your title is totally accurate, it's about FMCW radar. So if the person searching for this video is interested in specifically FMCW radar, they might be more likely to click - though that's definitely a much smaller fraction of people.

[@rohi_21]

Amazing video! Solved the challenge problem and posted the results on LinkedIn. Love the series and would love to contribute if I can to the development of more videos! Keep up the amazing work!

[@MarshallBrunerRF]

Super cool! Yeah that problem had a few ways to solve it - I want to do more involved ones in the future! What do you mean by contribute?

[@duncanmcallister7932]

You’ve mentioned radars in cars, but what are some other applications of FMCW Radars?

[@OscarzProductions]

They are used in radar altimeters and proximity fuses too.

[@MarshallBrunerRF]

Yeah Oscar mentioned some, but also factories will use them in tracking assembly lines, they're good for imaging because of the very fine resolution, etc.

[@walidazerkane9430]

For defense purposes like drone detection with phased array antennas

[@ianhutchinson9751]

Amazing video! I’m a software engineer and write applications responsible for tracking radar detections. If you know anything about tracking and are looking for video suggestions I’d be interested in some on that topic for sure 😊

[@JKTCGMV13]

Hell yeah

[@MarshallBrunerRF]

:)

[@pedrotoledo9070]

Why are radars so cool?

[@MarshallBrunerRF]

Yeah they're so awesome! So much more to cover too!