Single sine correlation

Refer to section 3.1.2.7 for more information about the single sine correlation process. Even measurement of one cycle of the waveform to be analyzed provides rejection of all harmonic frequencies, as can be seen from the upper trace in Figure 3.2.4. Additional cycles can be averaged to provide rejection of noise and subharmonics from the waveform, as demonstrated by the other two traces which show the improved rejection of spurious signals for 10 and 100 cycles of integration. 

Figure 3.2.4. Single sine correlation (rejection of noise and harmonics).

The synchronous and asynchronous spectrum, especially those expressed in terms of the amplitudes of cosine and sine function, clearly reveal the close resemblance of the functional forms to the ones given for the cospectrum and quad-spectrum in Equations (FIO) and (Fll). The amplitudes of cosine and sine component, respectively, of the dynamic spectrum with a single frequency 5 reflect the real and imaginary parts of the Fourier transform of the dynamic spectrum at the Fourier frequency of s = 5. Alternatively, the more general synchronous spectrum and asynchronous spectrum in Equation (F15) derived for the dynamic spectrum with arbitrary waveforms may be viewed as the collective sum totals of individual correlation spectra obtained for the corresponding Fourier components. 

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