baalke@mars.jpl.nasa.gov (Ron Baalke) (11/15/90)
MAGELLAN STATUS REPORT
November 14, 1990
The Magellan spacecraft is now in its 31st mapping orbit since radar
mapping was resumed last Saturday, November 10. All systems are nominal
and six of the seven star calibrations in the past 24 hours were fully
successful.
Yesterday, the software patch to control the solar panel positions with
ephemeris tables was sent to the spacecraft.
Further analysis of radar data from tape recorder track A4 now indicates
that it does show the progressive degradation that was seen on track 2.
Although the error rate causes only moderate image degradation, data
management stategies to avoid these tracks are now being studied.
Other analyses disclosed that the SAR (Synthetic Aperture Radar) sampling
window is not being accurately centered on the part of the signal echo
corresponding the the center of the SAR antenna beam. This problem may be
caused by an error in the estimated time of periapsis or some other timing
error. The problem may cause minor to moderate image quality degradation,
depending on whether the SAR processor can compensate for the effective
pointing error. The problem is being investigated.
Two bursts of radar data in each of several consecutive orbits have
exhibited abnormal amplitude characteristics. This problem is considered
minor because it affects less than 0.1% of the data from each orbit. This
anomaly was confirmed by the occurance of two bright patches in the test
image swaths of orbit #796.
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/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |