| 摘要 |
<p>The invention features interference signals for each of multiple Doppler shifts to thereby resolve nonlinearities, e.g., cyclic errors (90, 91, 92, 95), that may otherwise overlap spectrally with a dominant interference signal, and also interpolates the contributions of the nonlinearities to measurements at different doppler shifts. The time varying interference signal or the phase extracted from interference signal is Fourier transformed and at least some of the nonlinearities are associated with peaks in the square modulus of the Fourier transformed signal. The amplitude and phase of the Fourier transform at the frequency of each peak are used to quantify the nonlinearities. The quantified nonlinearities are used to correct optical pathlength measurements by the system.</p> |
