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performing an fft with specific frequency resolution

I have a 24 kHZ signal that was sampled for 16 seconds. When I take the fft I have a delta f of about 0.06 Hz. What I really need is to be able to see the data with a frequency resolution of something like 3.75 Hz as a part of order analysis. I realize that in order to do something like that I need to either reduce my number of samples or resample the data. Resampling has turned into a problem due to the amount of memory that it takes up. I have tried breaking the data up into chunks that will give me that 3.75 Hz resolution and then taking the ffts of each of those chunks. Now I want to take the average of all of these ffts but I am at a loss as to how to do this. Can anyone help me? Or am I just going about this completely the wrong way?
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The previous is the VI with my code so far. It was attached that way due to difficulties with attachments and this website.
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Hi Liz,

Perhaps you can try using shift registers on the second for loop to keep a running average of the fft.

Regards,
Stanley Hu
National Instruments
Applications Engineering
http://www.ni.com/support
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