R. Spang noticed on Oct 2008 an anomaly in some MIPAS L1b spectra of the FR mission in the January and December 2003 period.
The problem was found with a statistical analysis on a monthly basis of the cloud index in band A,
where 'unrealistic' extremely low values of CIA were found at high altitudes see Figure below.
These values of the CI indicate an anomaly in the radiometric calibration of the L1b data.
The problem is due to wrongly calibrated L1b products, for which the incorrect set of auxiliary files was used in the processing.
These anomalous data was deleted from the D-PAC ftp server and reprocessed (during Dec 2008)
with correct and updated auxiliary files, for the L1b products of the FR mission the corresponding L2 products were also generated.