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Difference Between TFSS Night and FEM Night

Image name: TFSS_FEM_tim2night.png (click image to enlarge)
Image size: 4.64900 KB (1024x256)
Date submitted: 14-Dec-1994

The difference (in seconds) between Yohkoh observed night (as indicated by the 
outputs of the Yohkoh Sun Sensors) and the Yohkoh predicted night (as reported
in the ephemeris or FEM files) are plotted.  Times were calculated relative
to the times of the SXT Terminator data records (SFT files) - Some periodic
behavior is evident (period ~40 days of course, and under study).

This plot includes points for the majority of SFT images taken in 1994 - 
however, only High rate telemetry points are shown since the TFSS cadence 
during Medium rate is insufficient for accurate 'predictions' without some 
additional analysis. (cadence limitation refer to the values in the ATR
files - perhaps higer cadence TFSS data is available in the ADA files?)

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