Administrative, NOAA-17 MIRP Rephase to Be Disabled, 9 March 2010 - Issued: 8 March 2010 2015 UTC

NOAA-17 MIRP Rephase to Be Disabled to Mitigate Data Loss Events Due to AVHRR Scan Motor Degradation

Date/Time Issued:
March 8, 2010, 2015 UTC

Product(s) or Data Impacted:

Date/Time of Initial Impact:
March 9, 2010, 0300 UTC

Date/Time of Expected End:

Length of Event:

Impacts on Users and Significance:
Possible major impact

Details/Specifics of Change:
NOAA-17 MIRP rephase will be disabled on 9 March 2010 at 0300 UTC. Recent instability in NOAA-17 AVHRR Scan Motor is believed to cause excessive amounts of MIRP rephrase events, which consequently result in the problems reported in the previous notification (below). Disabling the rephrase function of MIRP will mitigate the data loss events.

(Previous Notification Issued on February 19)
Recently the NOAA-17 AVHRR Scan Motor began having a timing synchronization problem between the AVHRR and the MIRP. On February 12, users started to report that they received images with a sudden displacement, had data gaps, and experienced failures in processing NOAA-17 direct readout data. The same problem was believed to be observed on the previous AVHRR Scan Motors in the past. It is an instrument aging issue. The solution has been to disable the automatic re-sync by the MIRP and to activate it on a schedule. Once we reach a decision on how to implement our new schedule/procedure, we will provide a follow-up notification.

Contact Person(s) Name/Email/Phone Number for Questions:
Dejiang Han 301-817-4119 Level 1B operations support

Web site(s) that contain other relevant information (where applicable): - History of level 1B notices - All user notices