Hi,
If I understand your question correctly, you want to find frequency of a signal/orbit/trajectory from a given sampling, say {{t1,x1},{t2,x2},...,{tn,xn}}?
You need to F1
Fourier[] function and you'll find an example at
Applications/Frequency Identification
Please note, that in example given they
do not use window function. Also convolution procedure can be made more precise by adding Newton method.
Even without windows and Newton method you can expect to get frequency with accuracy ~ 10^-7, with all additional staff ~ 10^-9.
You might consider searching the web for Laskar's NAFF algorithm.
I.M.
