More Information about the NOAA-15 AVHRR Failure
Thank you to Carl Reinmann (aka usradioguy) for submitting his blog post which goes into deeper detail about the NOAA-15 weather satellite imaging failure that we posted about last week.
In his post Carl discusses in detail the technical aspects of the AVHRR Scan Motor failure, shows plots of the AVHRR motor current increasing, provides multiple examples of corrupt images being recently received and notes the history of previous failures which were eventually resolved.
He also notes that even with the AVHRR failure the other sensors on the satellite will remain functional, however a failure of this instrument would mean the end of the easy to receive APT images at 137 MHz from NOAA-15. We note that there is still the opportunity to receive NOAA-18 and NOAA-19 which are the remaining operational satellites that transmit APT at 137 MHz.
NOAA have now also released an official notice about the failure which reads:
Product Outage/Anomaly: NOAA-15 AVHRR degraded image data issued by NESDIS NSOF
Date/Time Issued: Oct 22, 2022 1947Z
The NOAA-15 AVHRR Scan Motor current began showing signs of instability on Oct 18 at approximately 1800Z, when the current began to gradually rise from about 205 mA to about 250 mA, where it remained until Oct 24. At about 0000Z on Oct 24, the current began rising again throughout the day, peaking at about 302mA on Oct 25. Scan motor temperature began rising about the same time and is currently steady at ~29°C. The instrument is still producing data, but it is highly degraded. This behavior may be a sign of an impending scan motor stall but requires further investigation. Options for recovery are limited.