I'm trying to understand some data from a vibration sensor, in units of milli-g and in cartesian coordinates. One idea I had was to analyze the data in something like spherical coordinates, to understand if most of the vibration is radial, or how much is transverse along the angle dimensions. Can the FFT algorithm be used on data converted to spherical coordinates? Or are there similar algorithms for converting time series spherical coordinates to frequency domain? Can the FFT be used on the radial coordinate?
I have a physics background, but its been awhile. I'm trying to remember somethings from old courses and wanted to check if this is valid.