Increasing levels of GOES-12 sounder noise
GOES-12 sounder radiance images
Beginning in September 2009, the GOES-12 sounder instrument filter wheel began to experience problems (tied to syncronization issues associated with increased friction in the filter wheel bearing) that resulted in intermittent periods of noisy data and pixel dropouts — this was previously discussed on a 25 November 2009 CIMSS Satellite Blog post. Originally the problem was primarily affecting the shortwave IR channels (sounder bands 13-18) — however, at times it had an impact on all 19 of the sounder channels, as seen on a 17 December 2009 multi-panel display of GOES-12 sounder radiance images (above) from the CIMSS Realtime GOES Derived Product Imagery site. This GOES-12 sounder filter wheel problem is currently being investigated by NOAA/NESDIS engineers.
GOES sounder Total Precipitable Water product
While this GOES-12 sounder filter wheel problem persists, AWIPS users of GOES sounder Derived Product Imagery (DPI) such as Total Precipitable Water (above) and Cloud Top Height (below) will notice periods of noisy data characterized by widespread pixel drop-outs over the eastern US and adjacent portions of the Gulf of Mexico and the western Atlantic Ocean. Note that the sounder DPI over the western US (using data from GOES-11) does not exhibit any pixel drop-outs.
GOES sounder Cloud Top Height product