Time-Domain Smoothing Processing for Equivalence-Principle Test Using Free-Fall Method

We investigate the effect of the time-domain smoothing processing for the equivalence-principle test using the free falling method, compared to the low-pass-filter method. Theoretical calculation shows that the time-domain smoothing processing can suppress the high-frequency noises and does not cause pseudo-acceleration. The physical reason is that the time-domain smooth-processing method is an unweighted filtering and is unrelated to the polynomial fitting. The uncertain acceleration difference due to high-frequency mechanical vibrations in the equivalence-principle test for extended rotating bodies can be suppressed from 2μGal to 0.05μGal after the time-domain smoothing processing.