Topic:
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:
NOAA-17 AVHRR
Date/Time of Initial Impact:
March 9, 2010, 0300 UTC
Date/Time of Expected End:
Permanent
Length of Event:
Permanent
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 Dejiang.Han@noaa.gov 301-817-4119 Level 1B operations support
Web site(s) that contain other relevant information (where applicable):
http://www.osdpd.noaa.gov/PSB/PPP/PPP.html - History of level 1B notices
http://www.ssd.noaa.gov/PS/SATS/messages.html - All user notices