Thread continued in http://community.wolfram.com/groups/-/m/t/203422.

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.

Thanks for writing us. There are many different kinds of data that could be input and different kinds of frequencies represented by the data. For this reason, it's very hard to answer the question without a more specific example of what you'd like to do. Do you have a simple example of the kind of problem you are interested in solving?