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NOUS41 KWBC 111456
PNSNMC
NATIONAL TECHNICAL INFORMATION MESSAGE /NTEM/ 97-08
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
1000 AM EST TUE FEB 11 1997
TO: FAMILY OF SERVICES /FOS/ SUBSCRIBERS...NOAA WEATHER
WIRE SERVICE /NWWS/ SUBSCRIBERS...OTHER NATIONAL
WEATHER SERVICE /NWS/ CUSTOMERS...NWS EMPLOYEES
FROM: ROBERT S. WINOKUR
ASSISTANT ADMINISTRATOR FOR NATIONAL ENVIRONMENTAL
SATELLITE...DATA...AND INFORMATION SERVICES /NESDIS/
RON S. GIRD
NWS OFFICE OF METEOROLOGY SATELLITE PROGRAM MANAGER
SUBJECT GOES-9 MOTOR WINDING MITIGATION FOR SPRING 1997:
MITIGATION OPERATIONS FROM FEB 14 1997 TO FEB 28 1997
AND APRIL 9 1997 TO APRIL 23 1997
NESDIS PLANS TO CONDUCT THE GOES-9 MOTOR WINDING MITIGATION
OPERATION FOR THE SPRING ECLIPSE SEASON FOR TWO 15-DAY
PERIODS SURROUNDING THE ECLIPSE. WE PLAN TO BEGIN THE FIRST
MITIGATION OPERATION ON FRIDAY...FEBRUARY 14...AND CONTINUE
THROUGH FRIDAY...FEBRUARY 28. THE SECOND MITIGATION OPERATION
WILL BEGIN WEDNESDAY...APRIL 9...AND RUN THROUGH WEDNESDAY...
APRIL 23.
WHILE GOES-9 DATA AVAILABILITY WILL BE SEVERELY IMPACTED DURING
THE MITIGATION...WE HAVE SIGNIFICANTLY DECREASED THE TOTAL DAILY
OUTAGE FROM THE FALL 1996 OPERATION. FOR EACH DAY OF THE
MITIGATION PERIOD...THERE WILL BE NO IMAGER OR SOUNDER DATA FROM
GOES-9 FOR APPROXIMATELY 6.5 HOURS...FROM 0430Z TO 0500Z...AND
FROM 0630Z TO 1223Z. THIS IS A 1.5 HOUR IMPROVEMENT OVER THE
FALL MITIGATION. THIS IS THE RESULT OF THE PLANNED OPERATIONAL
IMPLEMENTATION OF THE CAPABILITY TO CORRECTLY NAVIGATE THE IMAGES
AND SOUNDINGS TAKEN BETWEEN 0500Z TO 0625Z WHEN THE SPACECRAFT IS
BIASED BY FOUR DEGREES.
FOR YOUR INFORMATION...IMAGE MOTION COMPENSATION WILL NOT BE
APPLIED DURING THIS PERIOD...RESULTING IN IMAGES THAT ARE NOT
REGISTERED WITH THOSE OUTSIDE OF THE MITIGATION PERIOD DUE TO THE
PERSPECTIVE CHANGE INDUCED BY THE SPACECRAFT BIAS.
A DETAILED SUMMARY OF THE SPACECRAFT AND INSTRUMENTS COMMAND
ACTIVITY FOR THE UPCOMING PROTECTION FOLLOWS. THE NESDIS OFFICE
OF SATELLITE OPERATIONS IS PREPARED TO BEGIN PROTECTION
OPERATIONS IMMEDIATELY ON GOES-8 IF THE IMAGER EXPERIENCES A
MOTOR WINDING FAILURE. IF YOU HAVE ANY QUESTIONS...CONTACT KATHY
KELLY AT 301-457-5130.
GOES-9 MOTOR MITIGATION FOR SPRING 1997
O MOTOR MITIGATION FOR THE SPRING 1997 ECLIPSE SEASON WILL
OCCUR PRIOR TO THE START OF THE ECLIPSE PERIOD AND AGAIN AT
THE END OF THE ECLIPSE PERIOD.
O FROM OUR EXPERIENCE DURING THE FALL 1996 ECLIPSE SEASON...WE
PROPOSE THAT THE APPROXIMATE 2-WEEK TIME SPAN BE CONTINUED.
O THE FIRST MITIGATION PERIOD WILL BE FEBRUARY 14...1997
/FRIDAY/ TO FEBRUARY 28...1997 /FRIDAY/.
O THE SECOND MITIGATION PERIOD WILL BE APRIL 9...1997
/WEDNESDAY/ TO APRIL 23...1997 /WEDNESDAY/.
O IMAGE MOTION COMPENSATION /IMC/ WILL BE COMMANDED OFF EACH
OF THESE DAYS FROM 0435Z UNTIL 0626Z.
O THE +4 DEGREE PITCH MANEUVER /EAST/ WILL START AT 0444Z.
O FOLLOWING RECONFIGURATION OF THE ATTITUDE AND ORBIT CONTROL
ELECTRONICS /AOCE/ AND SLEWING OF THE SOLAR ARRAY...THE
NOMINAL OPERATIONAL SCHEDULE WILL BE EXECUTED FROM 0500Z
UNTIL 0625Z.
O AT 0630Z EACH DAY...THE INSTRUMENTS WILL BE PARKED IN THEIR
RESPECTIVE AVOIDANCE POSITIONS /IMAGER-EAST...SOUNDER-
WEST/.
O FROM FEBRUARY 14 TO FEBRUARY 28...THE INSTRUMENTS WILL BE
PARKED NORTH OF THE DISK AND FROM APRIL 9 TO APRIL 23...THE
INSTRUMENTS WILL BE PARKED SOUTH OF THE DISK.
O EACH DAY AT 0844Z...THE SPACECRAFT WILL BE PITCHED -8
DEGREES WEST.
O AT 1123Z EACH DAY...THE INSTRUMENTS WILL BE COMMANDED TO
NADIR STARE POSITION
O AT 1130Z...THE +4 DEGREE /EAST/ PITCH MANEUVER WILL BE
EXECUTED TO BRING THE SPACECRAFT BACK TO ITS NOMINAL
POINTING POSITION.
O AT 1150Z...A SERIES OF FOUR INSTRUMENT STAR SENSES /TWO
IMAGER AND TWO SOUNDER/ WILL BE EXECUTED WITH EACH ACTIVITY
BEING 6.5 MINUTES IN DURATION.
O NOMINAL IMAGER AND SOUNDER OPERATIONS WILL CONTINUE AT
1223Z.
O IMAGER AND SOUNDER BASEPLATE HEATER OFF AND ON TIMES WILL BE
0300Z TO 0818Z AND 0500Z TO 0818Z...RESPECTIVELY...FOR
OPTIMUM THERMAL GAIN AND INSTRUMENT PERFORMANCE.
O BASEPLATE HEATER COMMANDING HAS NO IMPACT ON PRODUCT
GENERATION OR QUALITY.
END