Hello I would like to perform cross correlation between 2 burst signal to find the time of flight between two signals using LabVIEW software. If i perform with cross correlation VI, I just get the Rxy which is the coefficient. how to calculate the time of flight between 2 signals. Kindly help me out if you can.
Multi-Instrument is a powerful multi-function virtual instrument software. It is a professional tool for time, frequency and time-frequency domain analyses. It supports a variety of hardware ranging from sound cards which are available in almost all computers to proprietary ADC and DAC hardware such as NI DAQmx cards, VT DSOs, VT RTAs and so on. For example, if VT DSO-2820 (www.virtins.com/VT-DSO-2820.shtml) is used as the ADC device, it can sample at 200MHz and analyze up to 80MHz given an analog bandwidth of 80 MHz.
On the off chance that you still monitor this with no activity for 3 years; How do you convert the cross correlation maximum into the microseconds of delay? It may be the X-axis (Cross-correlation) value where the peak is located but it's hard to be certain from the images I can see.
@@VirtinsTech I'm having some problems trying to implement something similar to this using python. I input 2 identical waveforms, calculate the correlation (using scipy's correlate method), and then get the argmax of the resulting array. That just tells me that the maximum value is at x coordinate ~230,000, which for 15 seconds of wave doesn't convert to a time, and I would expect the value to be 0 since I'm inputting the same wave twice anyway. Am I missing something obvious in the process here?
@@matthewhenderson9292I am not sure how you find the argmax. The auto-correlation of an array with N elements contains 2N-1 elements. You probably need to search the max. in the output array.
Hi Matthew, have you figured the answer out yet? im stuck in the same problem you have. not sure how to adapt the x axis to get the right value of the time delay between 2 signals.
Yes, the auto correlation here is biased as an estimate of the statistical auto correlation. It is actually much more commonly used in practice than the unbiased auto correlation due to the following reasons: (1) The biased auto correlation and the power spectrum are simply a Fourier Transform pair (2) The biased autocorrelation down-weights the less reliable large-lag estimates when the discrete-time sequence has a finite length. It is statistically more stable than the unbiased autocorrelation, especially at the places where the lag is large. Therefore, when "auto correlation" is mentioned, it is usually implicitly referred to the biased auto correlation.
Thank you for your comments. Well, it is free with full functionality for 21 days. One way to keep it free permanently is to format the hard disk and reinstall the software every 21 days.......lol
Even though it is a coumputer voice, this Video and the practical demonstration was a imense help to me understanding the subject of time delay.
+Sebastian Speiser Hi there. Will this software help me find a correlation between two audio files? I can't understand this video.
yes, it can
Of course a 5 year old crappy text-to-speech RUclips video is the literally the only one I can find for my problem lol
Thanks tho
I feel your pain, bro
Terrible to have a computer voice explaining things like this. I could not concentrate more than 2 seconds
what an intuition so so lucid !!!
Very nice video , Thank you!
Hello I would like to perform cross correlation between 2 burst signal to find the time of flight between two signals using LabVIEW software. If i perform with cross correlation VI, I just get the Rxy which is the coefficient. how to calculate the time of flight between 2 signals. Kindly help me out if you can.
Find the peak of Rxy and its distance from the center of the Rxy array.
Hi sorry for the late response. Im getting both peak of Rxy and center of Rxy array as same value.
If the two signals are the same, then you will get the peak at the center. Otherwise, something is wrong with your configuration.
it's acheived!
From Indonesia : the great Software, hopefully I can using or access for long time, not for try for some day. Thank you.
can used to leakage water in puipline
Thank you for clear information.
how far better than an older DSA instrument, say stanford SR780, is this virtual instrument? what is the maximum processed signal frequency?
Multi-Instrument is a powerful multi-function virtual instrument software. It is a professional tool for time, frequency and time-frequency domain analyses. It supports a variety of hardware ranging from sound cards which are available in almost all computers to proprietary ADC and DAC hardware such as NI DAQmx cards, VT DSOs, VT RTAs and so on. For example, if VT DSO-2820 (www.virtins.com/VT-DSO-2820.shtml) is used as the ADC device, it can sample at 200MHz and analyze up to 80MHz given an analog bandwidth of 80 MHz.
Hard to understand but it's worthly
great explanation
wonderful
I will re record the audio for you if you want
Thanks. Maybe in the future.
On the off chance that you still monitor this with no activity for 3 years; How do you convert the cross correlation maximum into the microseconds of delay? It may be the X-axis (Cross-correlation) value where the peak is located but it's hard to be certain from the images I can see.
Yes, the delay in time is measured from the cross-correlation peak's x value.
@@VirtinsTech Thank you for the fast response!
@@VirtinsTech I'm having some problems trying to implement something similar to this using python. I input 2 identical waveforms, calculate the correlation (using scipy's correlate method), and then get the argmax of the resulting array. That just tells me that the maximum value is at x coordinate ~230,000, which for 15 seconds of wave doesn't convert to a time, and I would expect the value to be 0 since I'm inputting the same wave twice anyway. Am I missing something obvious in the process here?
@@matthewhenderson9292I am not sure how you find the argmax. The auto-correlation of an array with N elements contains 2N-1 elements. You probably need to search the max. in the output array.
Hi Matthew, have you figured the answer out yet? im stuck in the same problem you have. not sure how to adapt the x axis to get the right value of the time delay between 2 signals.
very nice video! good job!
Not that, this is a biased autocoorelation !
Yes, the auto correlation here is biased as an estimate of the statistical auto correlation. It is actually much more commonly used in practice than the unbiased auto correlation due to the following reasons: (1) The biased auto correlation and the power spectrum are simply a Fourier Transform pair (2) The biased autocorrelation down-weights the less reliable large-lag estimates when the discrete-time sequence has a finite length. It is statistically more stable than the unbiased autocorrelation, especially at the places where the lag is large. Therefore, when "auto correlation" is mentioned, it is usually implicitly referred to the biased auto correlation.
repeater
От души братишка анимешник
He says: "I lost my left leg between two elevator-doors".
I just hope your software is free.... lol.
Thank you for your comments. Well, it is free with full functionality for 21 days. One way to keep it free permanently is to format the hard disk and reinstall the software every 21 days.......lol
okay~ lol