Satellite engineers from NOAA’s Office of Satellite Operations (OSO) have informed the Office of Satellite Data Processing and Distribution
(OSDPD) of a series of tests on the NOAA-18 gyro sub-system. These tests are a result of ongoing analysis of the current operational
and backup NOAA-18 gyro sub-systems and concerns about the imminent failure of these systems resulting in unusable products within six
months. While NOAA-18 is considered a backup POES spacecraft, we understand that many users rely on NOAA-18 for operational data and
product processing, including input into global Numerical Weather Prediction models.
The NOAA-18 gyro tests will result in possible significant navigation errors during the tests of up to 100 km for many instruments. To that
end, OSDPD will process the NOAA-18 level 1b data on a backup system but cease the flow of NOAA-18 data to all operational products and
halt the distribution of NOAA-18 data to the NOAA CLASS archive.
Users obtaining data directly from NOAA-18 through APT or HRPT are advised of the possible severe degradation of the NOAA-18 data during
these tests.
Details of the tests are as follows:
– Initial NOAA-18 gyro test to take place beginning on 8/10/10 at 1130 UTC, running for 25.5 hours
– Second NOAA-18 gyro test to take place beginning on 8/12/10 at 1109 UTC, running for 24 hours
– A third NOAA-18 gyro test to take place approximately two or three months following second test.
12:53 UTC The huge navigation errors (anticipated and advised) are already obvious in
the APT imagery of NOAA 18 currently on its 25 hour gyro tests.