Aditya:
I am looking at sections of my data, one-M at a time - that is, from 0 MHz to 1 MHz, 1 MHz to 2 MHz, etc. So, for example, when I look at 0-to-1 MHz, I am using an FFT set to FFT-size of 1000. My data is about 13 seconds long, and I am looking at it at a rate of 1 Hz (so I see about 13 updates). What I am trying to see is if the data at about nine seconds persists to the end of the data at 13 seconds. I have tried holding the data at nine seconds and seeing if things keep matching up, but that is really not working out for me. I have yet to look at it from a Waterfall perspective, which may yield better results. However, in experimenting with the Waterfall, I am unable to get the "window" to be set the way I can set it with the FFT plot. I am getting ready to grab another data set tomorrow, but I would like to do some analysis prior to getting another data file.