Administrative, Update #1, NOAA-18 Reduced Gyro Test on 16 and 17 April 2011 - Issued: 15 April 2011 1745 UTC


NOAA-18 Reduced Gyro Test

Date/Time(UTC) Message Issued:

April 15, 2011, 1745 UTC

Product(s) Involved/Affected:

All data and products from NOAA-18 (AVHRR, AMSU-A, AMSU-B, HIRS, MHS, SBUV)

Date/Time(UTC) of Initial Implementation:

April 16, 2011, Time 12:24 UTC

Date/Time(UTC) of Expected End:

April 17, 2011, Time 15:34 UTC

Length of Outage:

27 hours and 10 minutes

Details/Specifics of Change:

Update #1:

The NOAA-18 Reduced Gyro Test will start at 12:24 UTC on April 16 (DOY 106) according to the original plan. The only change is that engineers will add one more action. They will perform the MHS Machine Error Count (MEC) memory dump during the DOY 106 Wallops contact between 17:11 UTC and 17:24 UTC. As a result, there will be no earth observations and users will experience a data gap only during this period. The MHS MEC memory dump will not affect other instrument observations.

The backup time for the MHS MEC memory dump will be the same UTC time on April 17, which is the backup date for the NOAA-18 Reduced Gyro Test


From 16 April 2011 at 12:24 UTC (orbit 30422) to 17 April 2011 at 15:34 UTC (orbit 30438), NOAA-18 will be placed into the Reduced Gyro Mode for a baseline test. Products may be impacted by slightly larger than normal yaw attitude disturbances. The performance of NOAA-18 instrument L1b data is expected to be similar to the counterpart of NOAA-15, which has been operated in the Reduced Gyro Mode since March 17, 2010.

The test will be ended on April 17th on REV 30438 AOS 15:34:10 UTC, and the spacecraft reconfigured for normal operation. The spacecraft will be commanded back to nominal mode on REV 30440 at 18:39:00.

Backup dates due to a Critical Weather Day Period cancellation are 17 April 2011 to 18 April 2011 roughly in the same UTC times as above.

Products that use NOAA-18 that will be affected:
ATOVS Polar Soundings
Radiation Budget
Fire Identification Mapping and Monitoring Algorithm (FIMMA) for Hazard Mapping system (HMS) input
SST and Coastwatch
Microwave Surface and Precipitation Products (MSPPS)
Microwave Integrated Retrieval System (MIRS)
Blended TPW
Ozone: SBUV/2
Ozone: TOAST
Ensemble Tropical Rainfall Potential (eTRaP)
Global Vegetation Index Products (GVI)

Contact Information for Further Information: ESPC Operations at at 301-817-3880