Signal processing

[patleb]

I have been using a Developers Suite for quite some time and have found some of the VI's in the signal processing tool kit very helpful. I am not involved in video processing at this point; lots of underwater acoustics. There are many VI's I have not used and there are limited examples in many cases. I have not found current resources that discuss DSP applications for most of the Vi's. What resorces are available?

Thanks.

pat

[patleb]

I have been doing signal processing for over 4 years and finding it is quite powerfull. I am looking for resources for apply more advanced concepts.

pat

[Jordan Kuehn]

If you are finding some of the built in signal processing tools lacking, I might suggest looking into MathScript (aka Matlab) nodes. Despite the work of NI, there is still a world of matlab signal processing code that is quite useful at times and this is a way to bring it into labview. (apologies if you were aware of this already)

[patleb]

I have used many FFT, convolution, crosscorrelation... vis and have produced excelent results. Mainly I use a PXI 1045 with PXI 5412 AWG, PXI 5922 Digitizer with other modules including timing module. Since I work with signals below 1MHZ this system has been great.

However I have the feeling I am just scratching the surface using DSP tools in LabVIEW. There is much in the Time Frequency Analysis-Spectrogram-Feature Extraction-JTFA-Gabor transforms etc that I really have no experience with. I am looking for good information on using these tools. There are some helpful examples at the NI website and in LabVIEW but there is not enough informaton for me to get a grip on using these tools efficiently.

[asbo]

It sounds more like you need to learn the DSP theory than about the VIs specifically. For whichever VIs you're interested in, use either the name of the VI or whatever documentation there is for it as a jumping off point for your Google searches. Yes, NI examples make it a lot easier, but sometimes you just have to learn the hard way.

[patleb]

I have a good DSP book, about a thousand pages and many of these ideas are not mentioned.

[Crown]

Any one with experience with cepstra and their interpretation, please help me understand this.  I calculated the auto spectum and the cepstrum of a square wave.  As expected, On the autospectrum, I got a strong component at the fundamental frequency (1 kHz, in my example) and the odd harmonics, whose amplitude decreasing nicely with the harmonic order.  On the cpstrum, I  was expecting events (or spikes, if plotted in absolute values) at the corresponding quefrencies of 1/1000, 1/3000, 1/5000, 1/7000, ... .  I am not getting this.  Please, give me your thoughts