| Description: | The Raman lidar was stuck in "calibration mode" (filter=3). Site operations restarted the
system, but it appears that the filter wheel associated with the low water vapor channel
became slightly off-sync at this time, and thus the filters were being incorrectly
positioned in the wheel. This effectively lets only a fraction of the light through the filter
and resulted in signal strengths that were at least a factor of 2 smaller than normal.
The problem was discovered in the data on 11/14 near the close of business PST, and site
operations corrected the problem on the 17th.
Only the low channel water vapor mixing ratio will be affected. As the VAPs provide
automatic calibration of the data, the only real effect should be much lower signal-to-noise
(especially during the daytime) from the low channel; i.e., for mixing ratio data below 1 km. |