cross correlation of monotonic signal












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I have two monotonic signals and I want to calculate the time delay between them.
Say for example my signals are:



s1 = [1 2 3 4 5]
s2 = [2 3 4 5 6]



To me these appear to be monotonic signals, with s2 having a delay of 1. But if I perform a cross correlation, which in my understanding is taking the dot product as I shift one of the signals, then the delay is calculated to be 0. The dot product of the unshifted signals is 70, which is larger than the dot product as I shift one of these signals and zero pad. I'm sure I'm missing something basic here, I'm just trying to understand why a cross correlation would not work here? Or more specifically why it doesn't give me the result of a single delay?










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$endgroup$

















    0












    $begingroup$


    I have two monotonic signals and I want to calculate the time delay between them.
    Say for example my signals are:



    s1 = [1 2 3 4 5]
    s2 = [2 3 4 5 6]



    To me these appear to be monotonic signals, with s2 having a delay of 1. But if I perform a cross correlation, which in my understanding is taking the dot product as I shift one of the signals, then the delay is calculated to be 0. The dot product of the unshifted signals is 70, which is larger than the dot product as I shift one of these signals and zero pad. I'm sure I'm missing something basic here, I'm just trying to understand why a cross correlation would not work here? Or more specifically why it doesn't give me the result of a single delay?










    share|cite|improve this question









    $endgroup$















      0












      0








      0





      $begingroup$


      I have two monotonic signals and I want to calculate the time delay between them.
      Say for example my signals are:



      s1 = [1 2 3 4 5]
      s2 = [2 3 4 5 6]



      To me these appear to be monotonic signals, with s2 having a delay of 1. But if I perform a cross correlation, which in my understanding is taking the dot product as I shift one of the signals, then the delay is calculated to be 0. The dot product of the unshifted signals is 70, which is larger than the dot product as I shift one of these signals and zero pad. I'm sure I'm missing something basic here, I'm just trying to understand why a cross correlation would not work here? Or more specifically why it doesn't give me the result of a single delay?










      share|cite|improve this question









      $endgroup$




      I have two monotonic signals and I want to calculate the time delay between them.
      Say for example my signals are:



      s1 = [1 2 3 4 5]
      s2 = [2 3 4 5 6]



      To me these appear to be monotonic signals, with s2 having a delay of 1. But if I perform a cross correlation, which in my understanding is taking the dot product as I shift one of the signals, then the delay is calculated to be 0. The dot product of the unshifted signals is 70, which is larger than the dot product as I shift one of these signals and zero pad. I'm sure I'm missing something basic here, I'm just trying to understand why a cross correlation would not work here? Or more specifically why it doesn't give me the result of a single delay?







      linear-algebra vectors signal-processing correlation






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      asked Dec 4 '18 at 18:24









      mashmash

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