Description: | Sometimes between Jan and March 2007 the V-band noise diode started to be unstable. V-band
channels during this period show large discrepancies with model computations. The
problem was evident during the month of January. During February and March the problem was less
visible, however measurement model comparisons show an increased bias. The instrument
was calibrated with LN2 on March 15 and the calibration results showed a large drift in the
calibration parameters. The hardware failure will have consequences in the retrievals
of temperature and relative humidity profiles.
It is difficult to establish when the failure started. Disregard the V-band channels
during this period. Vertical profiles of temperature and humidity are affected as well. Please
note that this DQR only covers the 7 channels (brightness temperatures) in the V-band
range (51 to 60 GHz). The 5 K-band channels (20-31 GHz) are not affected. |