TWP/VCEIL/C2 - occasional communication fault

Beginning August 30, 2005, the Nauru Ceilometer periodically went into a strange 
operational mode where the backscatter data exhibits vertical stripes.  Looking at the backscatter 
data - there are high amplitude oscillations occuring in the backscatter as a function 
of time at a given height.  The phenomenon appears to be more common at night.  Dates 
include: 30 Aug, 31 Aug, 1 Sep, 9 Sep, 15 Sep, 20 Oct, 22 Oct, 8 Dec, and others.

The fiber optic link to the ceilometer was faulty and causing periodic data corruption. 
The problem was corrected when the fiber optic line was replaced with a hard wired RS232 
link.

Data should be ignored during obvious periods of data corruption.

• Vertical visibility(vertical_visibility)
• Aerosol volume backscattering coefficient at 355 nm(backscatter)
• lon(lon)
• Second lowest cloud base height(second_cbh)
• -180.0 - +180.0(alt)
• Percentage of nominal factory setting (0 to 999%)(receiver_sensitivity)
• Millivolts at internal ADC input (0 to 2500)(background_light)
• Distance to the center of the corresponding range bin(range)
• Window contamination(window_contamination)
• Warning, alarm, and internal status information(status_string)
• North Latitude(lat)
• Time offset from base_time(time_offset)
• Lowest cloud base height detected(first_cbh)
• Laser temperature(laser_temperature)
• Raw data filename(filename)
• Degrees from vertical (-15 to +90)(tilt_angle)
• Percentage of nominal factory setting (0 to 999%)(laser_pulse_energy)
• Detection status.(detection_status)
• 6 character string describing instrument measurement parameters(measurement_parameters)
• Third cloud base height(third_cbh)
• Flag indicating aeri retrieval status(status_flag)
• base time in epoch(base_time)
• Altitude of highest signal(alt_highest_signal)
• Sum of detected and normalized backscatter(sum_backscatter)