Thanks a lot Lou and Marcus,
Lou -> I tried your spectrum.grc file with my data file instead of your
cosine + gaussian noise and it works. The "integrate" block is really the one I was looking for!
Now ideally I'd like to save only ONE spectrum instead of "animations"
How to achieve this (e.g. I would save a spectrum integrated over 30s)?
Also I'd like to display the frequencies in the x axis and not the time in (ms) as you did.
Maybe I can write my own python scripts to plot the data. I tried
to use the scripts in gr-utils such as plot_data but I don't know
exactly how to use it (the options...), would you have an example?
Marcus -> Thanks for your explanations for the sample rates
Many thanks again for your great help!