Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Comprehensive explanation of Aliasing?

  1. May 16, 2007 #1

    I need a comrehensive explanation of Aliasing? and its relation to filters...

    Thanks for the answers
  2. jcsd
  3. May 16, 2007 #2
    start with wikipedia...
  4. May 16, 2007 #3


    User Avatar

    Staff: Mentor


    Aliasing is what happens when you take a continuous signal and digitize it. It can only be approximated and as a result, smooth lines in a signal (whether they are a synthesized sound wave or a picture or some other signal is irrelevant) become jagged.
  5. May 16, 2007 #4
    Aliasing is a form of distortion that happens when you sample a signal with a frequency less than the nyquist rate, the sampling theory simply states that if we take a number of samples of a signal at double the rate of it's highest frequency, the original signal can be reconstructed using these samples, so what happens when you sample at a rate lower than nyquist is that there will be an aliasing effect.

    The aliasing effect could be removed by passing the signal through a low pass filter before sampling, thus we could calculate the band of the filter and multiply it by two and then sample at this rate.
  6. May 16, 2007 #5
    Thanks a lot guys, I have already used wiki...Thanks again!

    I will post my summary in the coming days so we all benifit from it!
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Comprehensive explanation of Aliasing?
  1. Anti-Aliasing Filter (Replies: 2)