Is there any simple formula for plotting spectrum (finding the intensity of each frequency component, Hertz by Hertz) from IQ recordings? Specifically I need to know how to read an IQ file and somehow dissect clusters of samples. I’ve written programs that deal with large amounts of data from files, so I think this shouldn't be too hard. I want to write my program so that it takes in a multi-hour IQ file and averages it like the 24-hour band averaging on the University of Twente WebSDR site. This would allow users to average an IQ file over time and see the most active frequencies and times. There’s no utility for this yet, and I’d like to write it and release it on my blog.
On a side note: is it possible to go “frame-by-frame” in an IQ file? For example, to follow the hops of a 900-MHz FHSS device.