Differences Doris - C04 (at the date of Doris series) Δx and Δy

It is mainly composed of a 10 day term, confirmed by the following complex Fourier spectrum

Complex spectrum of Δx-i Δy: periods > 1.5 day

Complex spectrum of Δx-i Δy: diurnal and sub-diurnal periods

High-frequency spectrum reveals residual tidal peaks with respect to the IERS model of the ocean tidal effects on polar motion. Some of them present amplitude well above the expected corrections on the tidal model. A least square fit of the most noticable tidal waves is reported there.

These peaks can mix different causes: atmospheric tide, defect in Doris treatment, defect in the ocean tidal model.

It is worth to note a ter-diurnal peak, at -0.33 day (S3) (about 10 μas), probably revealing the third harmonics of the S1 atmospheric thermal tide.

Allan deviation analysis of the Doris - C04 differences (at the date of Doris series)