![Figure 8](fts_glitch_2001_350_rev_rot.png)
Figure 8: Time series of Cassini two-way Ka-band frequency residuals from a DSS 25 track on
2001 DOY 350. The data are sampled at 0.2 s after being detected with a time constant
1 s.
At this time resolution, the visual appearance of the time series is dominated by high-frequency noise.
Superimposed on this noise are two systematic glitches which were traced to an intermittently-faulty
distribution amplifier in the signal chain providing frequency references to the transmitter and
receiver. The distribution amplifier fault acts like an FTS glitch and, in the two-way Doppler, appears
twice in the time series anticorrelated at the two-way light time (Figure 7). The glitches in the figure
are paired with the indicated two-way light time separation T2
5737.7 s. The lower panels show
blowups of the pair; the glitch waveforms are unresolved (shapes set by the impulse response of the
software phase detector) but clearly show the characteristic FTS anticorrelation.
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