How to Understand Aliasing in Digital Sampling 

YOU ARE PERFECT! I AM WATCHING YOUR VIDEOS FOR 3 DAYS WOW

Have to say that a new creative, successful explanation style is born. Thanks for creating the video. Cannot wait for more.

Greatly appreciated professor, your initiative to give special importance to intuition when teaching a concept is what impresses me the most!

Excellent video! Nyquist sampling theorem says that if you want to figure out how fast the bike tire is moving (frequency) and which direction it's moving, you need to sample it at least twice as fast as it is spinning. Sample slower than that and it'll look like the wheel is spinning backwards, even when it's spinning forward. You won't be able to tell if the wheel is spinning forward at f_nyquist + delta or f_nyquist - delta. This is aliasing where the spectrum "folds back" onto itself about the Nyquist sampling rate. Some designs actually rely on sampling in higher Nyquist regions, though it requires a high pass filter or band pass filter to guarantee that there is no frequency content below that Nyquist region. Otherwise you will get an aliased spectrum.

I like the bird yelling in the background towards the end

Another great explanation. Thanks. The star jumps are a wonderful example.

That was so helpful, thank you so much!

A remarkable approach on the theory of aliasing ! Very well and comprehensive explained !

this channel is great! thank you for all of your effort

I don't think there is a better video than this to explain aliasing.... Thanks a lot for the effort n knowledge........

Thank you for this. I wish my professor had explained it this way. So much more intuitive than staring at sine waves of different frequencies trying to puzzle out what the heck aliasing is from that.

Thank you for this artfully made and thought-provoking film. Best Regards 😉

Thank you for making so many wonderful videos. An example I like to use involves an ordinary clock with hour and minute hands. If we look at the clock every 11 hours, then the hour hand will appear to move backward 1 hour. Similarly for the minute hand if we observe it too infrequently it too will appear to move strangely. And many other false or aliased outcomes occur by sampling too infrequently as you have so nicely demonstrated.

Very brilliant explanations! Haven't been to Manly since covid

Amazing explanation!

Very clear and very good approach to move the concept to real world. Nice bicycle tough 👍🏻.

The True Professor

thanks bro you are inspiring

I really want to thank you, i have just understood decimation and interpolation with your videos , Good Luck from Algeria 🇩🇿 ❤️ I wish you make videos about Adaptive filters and Blind Source Separation , Thank you !

Wonderful explanation

Professor, the most impressive is your didactic - the easy way you explain difficult terms. Thanks. Obs: rim brakes are better than disk brakes … 😂

you are a magician as i always said professor

Nice explanation sir

Hi, I really liked the environments that you recorded the videos in (next to the sea, etc); can you tell me what country/city is that? it was very beautiful

Hello professor, I really appreciate your special explanation. But, what I am still confused about is the phase reversal. With ALIASING, the wheel looks rotating backward because of its angular freq.. But, the textbook said it is because of the phase reversal and I cannot understand it. Could you please explain the relationship between backward spinning of the wheel and the phase reversal?

Sir why nobody teaches how things happen, how to figure things out as a curious yet not properly guided youngster like me???. And i really want to ask why on the world should we learn aliasing . Just because i took electronics in graduation ? How should i see the physics behind it to use it in daily life

Do you have a pet pterodactyl ?

Was so easy to understand!