Correlation method estimation of the modulation signal in the weak equivalence principle test<xref rid="cpb_27_8_080402_fn1" ref-type="fn">*</xref> <fn id="cpb_27_8_080402_fn1"><label>*</label> <p>Project supported by the National Natural Science Foundation of China (Grant Nos. 11575160, 91636221, and 11605065).</p></fn>

Correlation method estimation of the modulation signal in the weak equivalence principle test* *

Project supported by the National Natural Science Foundation of China (Grant Nos. 11575160, 91636221, and 11605065).

Luo Jie¹, Shen Liang-Cheng¹, Shao Cheng-Gang^{2, †}, Liu Qi^{3, ‡}, Zhang Hui-Jie¹

Power spectral density of the angular deflection of the pendulum θ(t). (a) The power spectral density of the raw angular deflection. The peak f is the free torsional oscillation θ_d(t). The peaks f₁ and f₂ are the fundamental frequency and second harmonic components of the modulation signal while the other peaks are higher harmonic components of the modulation signal. (b) The power spectral density of the angular deflection after removing the free torsion oscillation, where the peak f is gone.