If I perform a FFT of a real signal which is limited on time (for example the atmospheric pressure in time from 0s to 5000s), is it possible that the fact that is limited on time can affect the FFT results? I read this thread and I don't know a priori how many cycles can fit inside it. Is it possible that spectral leakage occur? In the end it is like a big rectangular window.
Are there ways to overcome the effect of the limited sampled signal length?